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S. HRG. 109–1111 

PROJECTED AND PAST EFFECTS 

OF CLIMATE CHANGE: A FOCUS ON 

MARINE AND TERRESTRIAL SYSTEMS 

HEARING 

BEFORE THE

SUBCOMMITTEE ON GLOBAL CLIMATE CHANGE 

AND IMPACTS 

OF THE

COMMITTEE ON COMMERCE, 

SCIENCE, AND TRANSPORTATION 

UNITED STATES SENATE 

ONE HUNDRED NINTH CONGRESS 

SECOND SESSION 

APRIL 26, 2006 

Printed for the use of the Committee on Commerce, Science, and Transportation 

( 

(II) 

SENATE COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION 

ONE HUNDRED NINTH CONGRESS 

SECOND SESSION 

TED STEVENS, Alaska, Chairman 

JOHN MCCAIN, Arizona 

CONRAD BURNS, Montana 

TRENT LOTT, Mississippi 

KAY BAILEY HUTCHISON, Texas 

OLYMPIA J. SNOWE, Maine 

GORDON H. SMITH, Oregon 

JOHN ENSIGN, Nevada 

GEORGE ALLEN, Virginia 

JOHN E. SUNUNU, New Hampshire 

JIM DEMINT, South Carolina 

DAVID VITTER, Louisiana 

DANIEL K. INOUYE, Hawaii, Co-Chairman 

JOHN D. ROCKEFELLER IV, West Virginia 

JOHN F. KERRY, Massachusetts 

BYRON L. DORGAN, North Dakota 

BARBARA BOXER, California 

BILL NELSON, Florida 

MARIA CANTWELL, Washington 

FRANK R. LAUTENBERG, New Jersey 

E. BENJAMIN NELSON, Nebraska 

MARK PRYOR, Arkansas 

LISA J. SUTHERLAND, Republican Staff Director 

CHRISTINE DRAGER KURTH, Republican Deputy Staff Director 

KENNETH R. NAHIGIAN, Republican Chief Counsel 

MARGARET L. CUMMISKY, Democratic Staff Director and Chief Counsel 

SAMUEL E. WHITEHORN, Democratic Deputy Staff Director and General Counsel 

LILA HARPER HELMS, Democratic Policy Director 

SUBCOMMITTEE ON GLOBAL CLIMATE CHANGE AND IMPACTS 

DAVID VITTER, Louisiana, Chairman 

TED STEVENS, Alaska 

JOHN MCCAIN, Arizona 

OLYMPIA J. SNOWE, Maine 

FRANK R. LAUTENBERG, New Jersey, 

Ranking 

JOHN F. KERRY, Massachusetts 

(III) 

C O N T E N T S 

Page 

Hearing held on April 26, 2006 .............................................................................. 1 

Statement of Senator Lautenberg .......................................................................... 3 

Statement of Senator Stevens ................................................................................ 2 

Statement of Senator Vitter .................................................................................... 1 

WITNESSES

Akasofu, Dr. Syun-Ichi, Director, International Arctic Research Center, University of Alaska Fairbanks ................................................................................ 39 

Prepared statement .......................................................................................... 40 

Armstrong, Dr. Thomas R., Program Coordinator, Earth Surface Dynamics 

Program, U.S. Geological Survey, Department of the Interior ........................ 20 

Prepared statement .......................................................................................... 22 

Corell, Dr. Robert W., Senior Fellow, American Meteorological Society; Affiliate, Washington Advisory Group; Chair, Arctic Climate Impact Assessment ...................................................................................................................... 47 

Prepared statement .......................................................................................... 50 

Murawski, Ph.D., Steven A., Director of Scientific Programs/Chief Science 

Advisor, National Marine Fisheries Service and Ecosystem Goal Team 

Lead, National Oceanic and Atmospheric Administration, Department of 

Commerce ............................................................................................................. 5 

Prepared statement .......................................................................................... 8 

Reiter, Paul, Chief, Insects and Infectious Disease Unit; Professor, Institut 

Pasteur .................................................................................................................. 71 

Prepared statement .......................................................................................... 73 

APPENDIX

Inouye, Hon. Daniel K., U.S. Senator from Hawaii, prepared statement ........... 89 

Response to written questions submitted by Hon. Daniel K. Inouye to Steven 

A. Murawski, Ph.D. .............................................................................................. 89 

Response to written questions submitted by Hon. Frank R. Lautenberg to: 

Dr. Syun-Ichi Akasofu ...................................................................................... 98 

Steven A. Murawski, Ph.D. ............................................................................. 92 

(1) 

PROJECTED AND PAST EFFECTS 

OF CLIMATE CHANGE: A FOCUS ON 

MARINE AND TERRESTRIAL SYSTEMS 

WEDNESDAY, APRIL 26, 2006 

U.S. SENATE, 

SUBCOMMITTEE ON GLOBAL CLIMATE CHANGE AND IMPACTS, 

COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION, 

Washington, DC. 

The Subcommittee met, pursuant to notice, at 2:30 p.m. in room 

SD–562, Dirksen Senate Office Building, Hon. David Vitter, 

Chairman of the Subcommittee, presiding. 

OPENING STATEMENT OF HON. DAVID VITTER, 

U.S. SENATOR FROM LOUISIANA 

Senator VITTER. This is the Subcommittee on Global Climate 

Change and Impacts of the Senate Commerce Committee, and our 

hearing today is on the projected and past effects of climate 

change, a focus on marine and terrestrial systems. 

Thank you all for being here. Today, we’ll have a hearing on just 

that, the projected and past effects of climate change, with a particular focus on marine and land systems. 

It’s clear that we are experiencing a warming trend. Many scientists say that temperatures we’re seeing right now are not outside of historical ranges experienced on Earth; however, if temperatures continue to increase, we would be entering uncharted territory. 

Similarly, carbon dioxide concentrations in both our atmosphere 

and oceans are at levels never seen before. And while I enjoy forging new frontiers in many areas, this is not one any of us are excited to do. 

So, this hearing will concentrate on the realized historical and 

also future predicted impacts of climate change, specifically on the 

health of our oceans, humans, plants and animals, and other Earth 

systems. 

I’m very interested in examining, through this hearing, how 

much we can ascertain from historical climatic variation and apply 

this knowledge to current and future changes and conditions. For 

once, we’re not here to argue about the causes of observed warming 

trends or whether mandatory or market-based incentives are the 

best solution to reducing greenhouse gas emissions. Rather, we all 

agree that clearly understanding the potential changes we face in 

our environment as a result of this current cycle is an important 

task. 

2 

We’ve seen predictions that our seas will rise 30 feet, and other 

extraordinary estimates. Certainly, I hope those won’t come true. 

If so, I imagine many of us will have to migrate to higher ground 

in Alaska, maybe even run against Ted Stevens. I don’t look forward to that. I know what the outcome would be. 

In addition, the State of Louisiana has many low-lying coastal 

areas, as many in the Nation discovered after Hurricanes Katrina 

and Rita. The impressive work of LSU’s Spatial Reference Center 

and the Center for GeoInformatics and the National Geodetic Survey have been very helpful in providing data we need in our part 

of the world, in terms of that situation in south Louisiana. 

So, we’re facing many of these challenges at home. The land is 

sinking, levees are settling. We lose a football field of wetlands 

every 38 minutes. The Corps of Engineers is currently rebuilding 

our flood and hurricane protection systems without the design 

flaws of the past, but the issue of net sea-level rise is very important as we do that work, as well. 

Sea-level rise is just one component of the hearing today. The 

State of Louisiana is the largest producer of fisheries in the lower 

48, and we need to gain a better understanding of how ocean 

changes could affect our fishermen and the growing demand for 

wild, domestic seafood. 

We’ll also discuss other potential changes related to our polar 

and temperate glaciers, impacts on plants and animals, and, of 

course, the important issue of human health. 

I want to commend to my colleagues that we share the common 

goal of ensuring the best science and understanding of all of these 

potential future changes. 

As CEQ Chair Jim Connaughton testified at our last hearing, the 

U.S. is dedicating more resources to climate change science and 

technology than any other country, probably more than all other 

countries combined. We’re seeing reductions in our emissions intensity now, and we must continue these efforts to meet national 

goals. 

In closing, I want to point out that we have witnesses that have 

traveled from Paris and Fairbanks to be with us today. And, while 

I appreciate all of you being here today, I want to extend a special 

thanks to Dr. Akasofu and Dr. Reiter for your efforts to be with us. 

And I look forward to everyone’s testimony. 

With that, we’ll turn to the full Committee Chairman, Senator 

Stevens. 

STATEMENT OF HON. TED STEVENS, 

U.S. SENATOR FROM ALASKA 

The CHAIRMAN. Well, thank you very much, Senator Vitter, for 

conducting this hearing. 

At my suggestion, the full Committee created this new subcommittee to deal specifically with global climate change. And it’s 

imperative that the decisionmakers in all our governments and industry have the best possible science to rely upon as we deal with 

the problems of global climate change. 

There is a great deal of uncertainty, as we all know, about the 

causes, but I don’t think there’s much, really, doubt that there are 

changes taking place, and in particular in Alaska and the Arctic. 

3 

We have faced severe coastal erosion. We have faced polar glacier 

recession. We have had melting permafrost, migration of species, 

all sorts of problems regarding our forests, and increased risks of 

fires in Alaska. And our native villages have faced the problems of 

changes that are much greater than taking place anywhere else in 

the United States. 

We think that if we can understand and, really, watch what’s 

going on in Alaska, that the rest of the country will learn from it. 

And I hope that this hearing will demonstrate that. 

It is critical that we examine the problems of Alaska on the basis 

of sound science, and that’s why I’m delighted that there are some 

familiar faces here today, for me. Dr. Bob Corell is Chair of the 

Arctic Climate Impact Assessment Team, and he’s done a great 

deal of research. We’ll learn more about that today. And my longtime friend and advisor, Dr. Syun Akasofu, who directs our International Arctic Research Center in Fairbanks. He has, as you said, 

flown a long way, and I think it’s about the third time he’s come 

down this year, at our request, to appear in various ways. He 

earned his doctorate in studying the composition of the aurora borealis—‘‘northern lights,’’ to most people—and he’s devoted 20 

years now to studying the climate of our area. So, I know of no one 

in the world that I would rely on more than Syun, who has, I 

think, demonstrated his objectivity and his honesty, in terms of 

dealing with these issues. 

So, again, I think that this is a very timely hearing. I wish the 

whole Senate was here to listen to these people, because these are 

the people that can give us the information now that we ought to 

listen to as we try to consider some of the suggestions that are 

being made concerning what the Federal Government could do— 

should do concerning global climate change. 

Thank you very much. 

Senator VITTER. Thank you, Mr. Chairman. 

And we also have our Ranking Member, Senator Lautenberg. 

Thank you for being here, Senator. And if you have any opening 

statement, please feel free to make it. 

STATEMENT OF HON. FRANK R. LAUTENBERG, 

U.S. SENATOR FROM NEW JERSEY 

Senator LAUTENBERG. Thanks, Mr. Chairman. I’m pleased to be 

here. And I’m pleased, particularly, that our Chairman of the 

whole Committee is with us. 

We have, Mr. Chairman, a vote that’s started. And I don’t know 

what you’d like to schedule. Should we—I’ll make my statement, 

and then shall we adjourn for a few minutes to carry on with our 

business? I’m—— 

Senator VITTER. Why don’t we do just that, if it’s—— 

Senator LAUTENBERG. Yes. 

Senator VITTER.—agreeable to you. 

Senator LAUTENBERG. That’d be perfect. 

And one of the reasons that I’m pleased to share this platform 

today with each of you is the fact that you, in Louisiana and Alaska and New Jersey, are all threatened by these climate changes 

that we see and that we worry about, the sea-level rise and Atlantic storms, the increased air pollution, harm to our fisheries. But 

4 

we’re also affected by things that happen beyond our shores. We’ll 

be harmed by the impacts of global warming that occur across the 

oceans or on—even on the other side of the world. 

Now, if the Greenland ice sheet melts into the sea, we’ll be affected. If the glaciers of Central Asia disappear, taking water used 

for drinking and irrigation for more than a billion people with 

them, we will be affected. If the sea rises and washes over homes 

in Bangladesh, we will be affected. And if a range of plant and animal species go extinct, from frogs to sea coral to polar bears, we, 

all of us, will be affected. 

Thousands of scientists around the world have identified potential impacts of global warming, and many of their dire predictions 

are already coming true; in some cases, at a rate far faster than 

forecasted. The indicators include increased hurricane intensity, 

the retreat of glaciers, loss of sea ice, and our oceans are becoming 

more acidic. There is no dispute that these changes are occurring. 

Senator Stevens said it very clearly, and there is broad scientific 

consensus, that the global warming that we are experiencing is 

mostly due to human activity, not the result of natural climate cycles. 

The most common argument heard from those who oppose 

prompt action to address global warming is that we don’t want to 

wreck our economy until we’re absolutely sure that the threat is 

real. Well, there are two fallacies to this argument. First, reducing 

global warming will not wreck our economy. In recent years, some 

companies have reduced greenhouse gases and have actually found 

that they’ve saved money. Second, we can’t afford to delay taking 

action until every doubter is convinced. Once greenhouse gases 

enter our atmosphere, they’re going to remain for a long time, and 

we can’t continue to race toward catastrophe, hoping that we can 

throw the car in reverse at the last minute. We’ve got to slow it 

down now. 

We’ve heard these doubters before. Every time a meaningful protection of our environment or public health has been proposed, they 

raise reasons as to why we shouldn’t be concerned about it now. 

The tobacco industry successfully fought efforts to curtail its deadly 

products for decades, based on the claim, ‘‘We just didn’t know 

enough.’’ But we did know enough to justify taking action. 

In 1994, when President Clinton proposed stronger protections 

from air pollution, industry-funded think tanks argued that our 

economy would be ruined and that barbecues and fireworks on the 

4th of July would be barred. But after President Clinton strengthened air-quality standards, our economy did thrive, and fireworks 

and barbecues continued. 

Now, we know that global warming is occurring. We also know 

it will continue to increase even if we act quickly to flatten and 

then reduce our greenhouse gas emissions. We know that the impacts of this warming are already being observed, and that it will 

continue and quicken, particularly if we take no action to reverse 

our current course. 

So, our country’s got to act. And this doesn’t mean that when we 

act, that we’ll see an immediate result. But at some point a beginning has to be made, and failure to do so could be our greatest failure as a nation and as human beings. 

5 

Now, I’m pleased that we have two panels of witnesses today before us. I’m particularly interested in the views of Dr. Corell, whose 

ideas on this matter are well respected, as are others in the field 

of climate science. 

Mr. Chairman, I went down to the South Pole a few years. I 

wanted to see what the National Science Foundation was doing. 

And it seemed to me, at night, that you could almost hear the glaciers groaning as there were climate shifts and as the temperatures 

changed. And 70 percent of the world’s fresh water was stored in 

those—in that ice. Much of that ice has disappeared, and much 

more of it will disappear. 

And so, once again, Mr. Chairman, I thank you for doing this. 

I look forward to hearing from our witnesses, and sorry that we 

have to delay them, but we’ll be back. It’s been said before. 

Senator VITTER. Thank you, Senator. 

And right now we’ll take a very brief recess to vote on the Senate 

floor, and we’ll all return absolutely as quickly as possible. I apologize for the delay. 

[Recess.] 

Senator VITTER. We’ll reconvene the hearing. Thanks to everyone, particularly our witnesses, for their patience. 

We’ll start with Panel I, comprised of two individuals. First, Dr. 

Steve Murawski, Director of Scientific Programs and Chief Science 

Advisor for the National Marine Fisheries Service and Ecosystem 

Goal Team Lead with the National Oceanic and Atmospheric Administration, and then he’ll be followed by Dr. Thomas Armstrong, 

Program Coordinator of the Earth Surface Dynamics Program with 

the U.S. Geological Survey. 

Thank you both for being here. And, Dr. Murawski, please begin. 

STATEMENT OF STEVEN A. MURAWSKI, PH.D., DIRECTOR OF 

SCIENTIFIC PROGRAMS/CHIEF SCIENCE ADVISOR, 

NATIONAL MARINE FISHERIES SERVICE AND ECOSYSTEM 

GOAL TEAM LEAD, NATIONAL OCEANIC AND ATMOSPHERIC 

ADMINISTRATION, DEPARTMENT OF COMMERCE 

Dr. MURAWSKI. Good afternoon, Chairman Vitter and Chairman 

Stevens. Thanks for the opportunity to testify. 

Among NOAA’s diverse missions, our tasks include understanding and predicting changes in the Earth’s environment and 

acting as the Nation’s principal steward of coastal and marine resources critical to our Nation’s economic, social, and environmental 

needs. 

Climate change is only one of a complex set of interacting factors 

that simultaneously influence the marine ecosystems. It is challenging, but vital, for us to isolate the influences of individual factors, such as natural and anthropogenic climate cycles and other 

influences, such as pollution, land development, fishing pressures, 

and others on ecosystems. 

In order to manage such a complex set of human activities, 

NOAA is committed to an ecosystem approach that addresses the 

many simultaneous pressures affecting resources, including the effects of climate change. 

Because changing climate is one of the significant long-term influences on marine species, we must meet this challenge head-on. 

6 

Climate-related issues are of particular concern for marine ecosystems that include the effects of long-term rising sea levels, increasing acidification of the world’s oceans, bleaching of shallowwater coral reefs, loss of sea ice, and rising water temperatures. All 

of these factors have been documented as influencing marine ecosystems, and all are cause for concern. As Winston Churchill said, 

‘‘The farther backward you can look, the farther forward you’re 

likely to see.’’ 

Paleoclimate and paleoecological indicators provide perspective 

on the scale of recent observed changes in marine ecosystems. Over 

hundreds of thousands of years, numerous ice ages and warming 

events have occurred, and populations have responded by changing 

growth patterns, abundance, and geographic location. 

Over the last 10,000 years since the last ice age, there were 

slightly warmer than average conditions during 1200 to 1400 A.D., 

slightly cooler conditions from 15- to 1800 A.D.—that is the Little 

Ice Age—and an increase in the last centuries to temperatures that 

are the warmest in the last millennium. 

Companion biological records show that, as compared to the preceding 1,000 years, organisms and the ecosystems are now exhibiting unusual patterns of growth, abundance, distribution, and 

other characteristics. 

Recent changes in the Earth’s climate are having observable impacts on marine ecosystems and the human communities that depend on them. Rising sea levels alter ecosystems and habitat in 

coastal regions. The coastlines of our Atlantic and Gulf States, as 

well as portions of Alaska and the Pacific Islands are especially 

vulnerable to long-term sea-level rise. For example, coastal Louisiana is projected to have sea-level rise 3 to 4 feet over the next 

century. Factors contributing to sea-level rise in coastal Louisiana 

are complex and multifaceted. Rising sea levels in coastal Louisiana are having effects on coastal marshes that are important to 

nursery areas for Gulf Coast fisheries. 

The oceans are the largest reservoir of carbon dioxide. Estimates 

are that by the middle of this century, atmospheric carbon dioxide 

levels will increase, resulting in a decrease in the surface water pH 

by approximately 0.4 pH units. 

As the oceans become more acidic, more species of marine plankton will have a reduced ability to produce protective calcium carbonate shells. These plankton species are the base of the marine 

food web, and shifts in the base can have cascading consequences 

through trophic levels. The loss of calcium carbonate will also have 

negative impacts on the world’s coral reefs, which are areas of the 

highest biodiversity in the ocean. Coral reefs are also extremely 

vulnerable to sea surface temperatures. Rising global temperatures 

over the past 30 years have been accompanied by an increase in 

the extent and frequency of coral bleaching in many tropical areas 

of the world. September of 2005 was, by far, the warmest in the 

eastern Caribbean in the entire 100-year record that we have. 

Many of these areas experienced over 90 percent of corals bleached, 

and 30 percent of the corals have died in some of these areas. This 

loss is significant, as coral reef ecosystems are among the most diverse and biologically complex areas in the oceans. 

7 

The loss of sea ice has been documented in both the Arctic and 

the Antarctic. The amount and duration of ice cover in the southeast Bering Sea has decreased substantially since the early 1970s 

as the southeast Bering Sea has warmed 2 to 3 degrees Centigrade 

in the past 10 years. These changes have had substantial biological 

impacts on the distribution and abundance of many commercial 

finfish and shellfish species. This means that the resource base 

supporting individual communities has been displaced, affecting 

the economics of fisheries and the communities. Other changes in 

the food web of the Bering Sea have occurred, affecting marine 

mammals and subsistence hunting for them. 

Temperatures in the South Shetland Islands in Antarctica have 

warmed by over 4 degrees Centigrade since the 1940s, and the extent of ice around Antarctica has declined appreciably. The density 

of krill, a central link in the Antarctic food web, has decreased by 

more than 90 percent in the region since 1976. Declines in krill 

have been associated with decreasing populations of penguins, 

seals, and other marine life. 

In temperate regions, many marine fish and shellfish species 

have been observed to shift their distributions northward in response to warmer waters. 

This is just a sample from the growing body of evidence linking 

climate change to marine ecosystem function. It is our challenge to 

understand these linkages both to better predict their effects and 

to identify the conservation and management policies in the face of 

changing climate that may help to mitigate their effects. 

Improving the predictability of ocean responses to a changing climate will require improvements in ocean observing, research, and 

modeling. A large broadscale and robust system for observing and 

measuring oceanographic climate and economic conditions is essential to better understanding climate change effects and ecosystem 

effects. 

To provide such a comprehensive set of measurements, the Administration and NOAA have supported the development of the 

U.S. Integrated Ocean Observing System, or IOOS. The full development of IOOS is a high priority for improving our understanding 

of climate effects on marine ecosystems. 

And, last, the President’s FY 2007 budget request restores significant cuts made by Congress in NOAA’s climate program in 

2006. This funding is critical to NOAA’s ability to understand and 

study climate change, including the impacts of climate on ecosystems. And we urge the Committee to support NOAA’s FY 2007 

budget request. 

Thank you, Mr. Chairman. I’d be happy to answer questions. 

[The prepared statement of Dr. Murawski follows:] 

PREPARED STATEMENT OF STEVEN A. MURAWSKI, PH.D., DIRECTOR OF SCIENTIFIC

PROGRAMS/CHIEF SCIENCE ADVISOR, NATIONAL MARINE FISHERIES SERVICE AND

ECOSYSTEM GOAL TEAM LEAD, NATIONAL OCEANIC AND ATMOSPHERIC

ADMINISTRATION, DEPARTMENT OF COMMERCE

Introduction 

Good afternoon, Mr. Chairman and Members of the Committee. My name is Steven Murawski, and I am the Director of Scientific Programs and Chief Science Advisor at the National Marine Fisheries Service (NMFS), within the National Oceanic 

and Atmospheric Administration (NOAA). I also serve as leader of NOAA’s EcoVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00011 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
8 

system Goal Team, which integrates the Agency’s many ecological activities across 

its various offices. Thank you for inviting NOAA to discuss projected and past effects of climate change with a focus on marine and terrestrial ecosystems. Among 

NOAA’s diverse missions, our tasks include understanding and predicting changes 

in the Earth’s environment and acting as the Nation’s principal steward of coastal 

and marine resources critical to our Nation’s economic, social and environmental 

needs. 

Today I will focus my remarks on how changes in climate affect marine ecosystems, particularly as they relate to NOAA’s stewardship responsibilities. NOAA’s 

work on climate change and ecosystems relevant to this hearing includes observations of the physical environment and biota, research to understand the changes in 

the environment and the broader ecosystem, and incorporating projected impacts of 

climate change into NOAA’s conservation and management programs for living marine resources and ecosystems. Climate change is only one of a complex set of factors that influence marine ecosystems. It can be difficult to separate the influence 

of natural climate cycles, recent climate change, and other factors such as overfishing, air pollution such as sulfates, agricultural run-off, land use changes resulting from land fills, drainage practices, uses of pesticides and fertilizers, development, recreational facilities and practices, inadequate storm water management, 

and sewage treatment. NOAA is committed to an ecosystem approach to resource 

management that addresses the many simultaneous pressures affecting ecosystems. 

This Administration recognizes climate change as a complex and important issue 

and acknowledges human activities are contributing to recent observed changes in 

the climate system. However, scientific uncertainties still remain, including how 

much of the observed warming is due to human activities and how large and fast 

future changes will be. In 2002, the Administration created the Climate Change 

Science Program (CCSP; the Federal interagency program focused on climate 

change research) to ensure the Federal Government’s efforts and resources are used 

to obtain the best possible scientific knowledge as the foundation to address challenging climate change questions and support decisionmaking. There is much important research yet to be done and CCSP—whose leadership resides in NOAA—is 

seeking to increase our understanding of climate change. Within CCSP there is an 

Ecosystem Interagency Working Group which is currently examining a variety of 

topics relevant to today’s hearing, including: (1) the use of integrated modeling systems, observations, and process studies to project the effects of climate variability 

and change on near-coastal and marine ecosystems and communities; (2) combined 

effects of changes in land use and climate on non-point sources of pollution entering 

estuaries; and (3) a long-term study of the western U.S. mountains and the relationship of observed sudden ecosystem changes to changes in climate conditions. 

The Climate Change Science Program is a coordinated effort across 13 agencies 

(U.S. Agency for International Development; Department of Agriculture; Department of Commerce, National Oceanic and Atmospheric Administration and National 

Institute of Standards and Technology; Department of Defense; Department of Energy; Department of Health and Human Services, National Institutes of Health; Department of State; Department of Transportation; Department of the Interior, U.S. 

Geological Survey; Environmental Protection Agency; National Aeronautics and 

Space Administration; National Science Foundation; and the Smithsonian Institution), 12 of which fund CCSP research. Funding for NOAA’s CCSP initiatives are 

included within the NOAA Climate Program. The fiscal 2007 President’s budget request for NOAA includes spending for CCSP near-term research focus areas, including integrating new remote-sensing observations with expanded observations to 

build the next generation of climate prediction capabilities; development of an integrated Earth system analysis capability; integrating of water cycle observations, research and modeling; using global LANDSAT data to answer critical climate questions; an integrated North American Carbon Program; understanding the impacts 

of climate variability and change on ecosystem productivity and biodiversity; coping 

with drought through research and regional Partnerships; the International Polar 

Year; and an Integrated Ocean Observing System. The President’s budget restores 

cuts made by Congress to NOAA’s Climate Program in 2006, particularly in the 

area of Research Supercomputing, critical to NOAA’s ability to reduce some of the 

highest uncertainties in understanding impacts of climate variability and change. 

We urge the Committee to support the FY 2007 President’s budget request for 

NOAA. 

In my testimony today I will: (a) provide information on NOAA’s contributions relevant to climate change science and links to effects on marine ecosystems, (b) detail 

the importance of understanding climate-ecosystem links both for the affected marine areas and the human communities dependent upon them, (c) briefly describe 

some paleontological observations of how ecosystems have changed in response to 

9 

climate variations in the past, and (d) review some contemporary observed changes 

in marine ecosystems thought to be related to changes in the Earth’s climate and 

issues surrounding them. Finally, I will outline some of the scientific challenges and 

needs for improving science to better define ecosystem impacts and inform conservation and management strategies for living marine resources taking into account climate impacts. 

NOAA’s Roles in Climate and Ecosystem Sciences 

Within the climate science community, NOAA is a recognized leader both nationally and internationally. Our scientists actively participate in many important national and international climate working groups and assessment activities. One of 

NOAA’s mission goals is to ‘‘understand climate variability and change to enhance 

society’s ability to plan and respond.’’ NOAA is the only Federal agency that provides operational climate forecasts and information services (nationally and internationally). NOAA is the leader in implementing the Global Ocean Observing System (NOAA contributes 51 percent of the world-wide observations to GOOS, not including satellite observations). NOAA also provides scientific leadership for the 

Intergovernmental Panel for Climate Change Working Group I and CCSP. To better 

serve the Nation, NOAA recently created a Climate Program Office (CPO) to provide 

enhanced services and information for better management of climate sensitive sectors, such as energy, agriculture, water, and living marine resources, through observations, analyses and predictions, and sustained user interaction. Services include 

assessments and predictions of climate change and variability on timescales ranging 

from weeks to decades. 

Within the ecosystem community, NOAA’s ecosystem researchers have been at the 

forefront of establishing links between ocean variability and impacts on marine ecosystems. NOAA has funded some research programs specifically dedicated to evaluating impacts of changes in the physical environment on marine resources. These 

include a program jointly undertaken with the National Science Foundation called 

GLOBEC (Global Ocean Ecosystem Dynamics), which just last week co-hosted a 

symposium on ‘‘Climate variability and ecosystem impacts on the North Pacific’’ 

with PICES (the North Pacific Marine Science Organization of which the U.S. is 

also a member). An exclusively NOAA program called NPCREP (North Pacific Climate Regimes and Ecosystem Productivity) seeks to improve climate-ecosystem 

science in the Alaskan Large Marine Ecosystem complex. Even more information on 

the impacts of climate on marine ecosystems is derived from NOAA’s many observing programs established to aid in the management of fisheries, protected species, 

marine sanctuaries, corals and other specific Agency mandates. 

These data, primarily collected in support of NOAA’s ecosystem stewardship authorities, provide a wealth of information for interpreting climate impacts when 

combined with NOAA’s climate, oceanographic and weather information. Results of 

these analyses have been widely disseminated and NOAA’s contributions to the 

emerging science of ecosystem impacts of climate change have been significant. 

However, a greater understanding of the full range of climate induced impacts on 

ecosystems will require us to increase our observation of ecosystems in relation to 

variable climate forcing and focus our research on the mechanisms through which 

ecosystems are affected. In this way we can develop quantitative assessments and 

projections of climate’s ecological impacts, including impacts on the resources on 

which human communities rely. 

Why are Links between Climate and Marine Ecosystems So Important? 

Irrespective of the ultimate causality, changes in the world’s climate has resulted 

in changes in marine ecosystems, on several different time scales, affecting the 

abundance, distribution and feeding relationships among components of many marine communities 1, 2, 3, 4, 5, 6 While we are still working toward a complete understanding of the causes of the observed phenomena, recent projections indicate that 

a number of climate change scenarios have the potential to affect marine ecosystems 

in even more fundamental ways. These changes are related both to long-term trends 

in the ocean environment and to the cyclic variation in ocean conditions observed 

in many areas. These changes are important in their own right, but even more so 

because of the dependence of many of our coastal communities on living marine resources—for food, recreation, and cultural fulfillment. Over half of the U.S. population now lives within 100 miles of the coast, and this proportion is increasing dramatically. Our $60 billion per year seafood industry, marine tourism industries, recreational activities, and the very existence of some communities may be dependent 

on changing ocean conditions affecting marine ecosystems. 

Changing climate is one of the most significant long-term influences on the structure and function of marine ecosystems and must therefore be accounted for in 

10 

NOAA’s management and stewardship goals to ensure healthy and productive ocean 

environments. Changes and variations in climate may directly or indirectly impact 

marine ecosystems. This includes changes and variations of sea surface temperature, ocean heat content, sea level, sea ice extent, freshwater inflow and salinity, 

oceanic circulation and currents, pH, and carbon inventories. Each of these properties of the global ocean is being measured to varying degrees by NOAA. Through 

the continued collection of data and the implementation and integration of observing 

systems, we strive to create longer, more globally inclusive data records that will 

improve our understanding of climate change and our ability to reliably predict impacts on marine ecosystems over time scales of interest to our constituents now 

(e.g., 5–10 year time horizon) and in the future. 

A Paleontological Perspective on the Impacts of Climate Change on Marine 

Ecosystems 

The paleoclimate record provides a long view of how populations and entire ecosystems have responded to climate change over hundreds to thousands of years. 

Many sources of paleoclimate data are from biological indicators such as tree rings, 

corals, and fossil plankton. By comparing the time series from biological indicators 

with paleoclimate data from non-biological material such as ice cores, boreholes, and 

cave stalagmites, one can reconstruct not only how climate has changed, but also 

how marine and terrestrial populations have responded. 

Over hundreds of thousands of years, ice ages have come and gone, and populations have responded by changing growth patterns, abundance and geographic location. Remarkably only a few documented extinctions occurred in terrestrial and 

marine ecosystems during ice age cycles, apart from the extinction of the Pleistocene 

megafauna (e.g., the woolly mammoth). Just as the changes in climate during the 

ice ages were large and sometimes abrupt, ecosystem changes were similarly large 

and abrupt. For example, at the end of the last ice age, pollen from lake sediments 

indicate an abrupt northward migration and establishment of the modern biomes 

across North America,7 while in the adjacent oceans fossil plankton from marine 

sediments reveal that the region where certain plankton species were abundant also 

moved to higher latitudes.8

While these changes in the ocean environment were abrupt compared to the radiation changes that caused the ice ages, the changes were slow compared to the 

changes occurring in the current millennium. The end-of-the-ice-age ecosystem 

changes occurred over thousands of years. Over the last 10,000 years climate has 

remained relatively stable apart from small changes caused by the changes in seasonal solar radiation. Over the past 1,000 years, where the paleoclimate record is 

most complete, climate has been even more constant except for the recent trends 

in temperature and rainfall. The climate of the last 1,000 years can be characterized 

as: 1200–1400 AD—slightly warmer than average conditions; 1500–1800 AD— 

slightly cooler than average conditions; and 1900–2000 AD—an increase in the last 

centuries to temperatures that are likely to be the warmest in the last millennium.9, 10 Companion biological records show that organisms and ecosystems are 

changing in growth pattern, abundance, and other characteristics in ways that are 

unusual compared to the preceding 1,000 years. Detailed information on terrestrial 

and marine ecosystem responses to past climate change is detailed on the NOAA 

Paleoclimatology website (www.ncdc.noaa.gov/paleo). One selected example relevant 

to marine ecosystems involves the long record of sockeye salmon populations in 

Alaska. 

The paleoclimate record of sockeye salmon from Alaskan lakes reveals the difficult 

task of separating the influence of natural climate cycles, recent climate change, and 

fishing pressure on salmon abundance. Sockeye salmon return to lakes in Alaska 

to spawn, and their remains are reflected in chemical (e.g., nitrogen-15) concentrations in lake sediments, creating a 2000 year-long record of salmon abundance. Dr. 

Bruce Finney, from the University of Alaska, and his colleagues correlated centuries-long cycles in salmon abundance with climate variations from other paleo 

proxies, demonstrating the existence of natural cycles in salmon populations prior 

to significant human activity in the region.11 Near the end of the record the decline 

due to intense fishing pressure in the last century is also evident. Finney and colleagues note that natural cycles in salmon abundance appear out of phase with the 

abundance of other fish species farther south in the California Current system, a 

pattern they also attribute to natural climate variability. In addition to fish abundance, paleo-ecological records have also been developed for plankton that form the 

base of the food chain. Compared to the fish proxies, the plankton records are more 

complete and subject to fewer uncertainties. While these records are continuously 

being developed, the records published so far document a clear link between climate 

11 

change and marine ecosystems. One important conclusion from this work is that 

marine ecosystems are sensitive to even small changes in climate. 

Current and Projected Impacts of Climate Change on Marine Ecosystems 

and Living Marine Resources 

Impacts of Sea Level Rise on Ecosystems 

Sea level rise is projected to accelerate during the 21st century, with the most significant impacts in low-lying regions where subsidence and erosion problems already 

exist. Rising sea level has worldwide consequences because of its potential to alter 

ecosystems and habitat in coastal regions. Sea level rise and global climate change 

issues in the coastal zone include: 

• Higher (deeper) and more frequent flooding of wetlands and adjacent shores; 

• Increased flooding due to more intense storm surge from severe coastal storms; 

• Increased wave energy in the nearshore area; 

• Upward and land-ward migration of beaches; 

• Accelerated coastal retreat and erosion; 

• Saltwater intrusion into coastal freshwater aquifers; 

• Damage to coastal infrastructure; and 

• Broad impacts on the coastal economy. 

The coastlines of our Atlantic and Gulf states, as well as portions of the Alaska 

coastline are especially vulnerable to long-term sea level rise. The slope of these 

areas is so gentle that any small rise in sea level can produce a large inland shift 

of shoreline. 

Sea level rise threatens to alter wetland ecosystems. Sea level rise may also result 

in increased susceptibility to nutrient-related eutrophication, due to changes in estuarine circulation. Changes in the wetland and estuarine processes will affect resident marine organisms and the fisheries dependent upon them. 

NOAA has maintained long-term continuously operating stations of the National 

Water Level Observation Network (NWLON), and has recently documented the relative sea level trends at all of the longest-term stations (1854–present). The map 

below (also available at http://tidesandcurrents.noaa.gov/sltrends/slrmap.html) 

shows sea level trends for the United States for those locations where tide stations 

exist. This map provides an indication of the differing rates of relative sea level rise 

(vertical land and sea level motion combined) around the United States. There is 

a general scientific agreement that sea level rise is occurring at a global average 

rate of 2 mm per year. Referring to the map the mid-Atlantic and Gulf Coast are 

experiencing 3–5 mm and 5–15 mm per year rise in sea level, respectively. 

12 

One area particularly vulnerable to sea level rise is coastal Louisiana. The graphic above illustrates that these areas are projected to have sea levels rise 3–4 feet 

over the next century. Factors contributing to sea level rise in coastal Louisiana are 

complex and multifaceted, including land subsidence due to petroleum extraction, 

declining sediment loads deposited from rivers into the marshes, land use practices 

exacerbating wetlands loss, and rising sea levels due to global climate change and 

other factors. Whatever the causes, a 3–4 foot rise in sea level in coastal Louisiana 

will have profound effects on marine resources, since coastal marshes there are important nursery areas for most of the valuable living resources (e.g., shrimp, oysters, 

many finfish species) in the Gulf of Mexico. In addition, loss of Louisiana’s coastal 

marshes to sea level rise makes coastal communities much more vulnerable to recurring storm events. 

The Northwestern Hawaiian Islands (NWHI) are of particular concern with respect to sea level rise. The NWHI have high conservation value due to their concentration of endemic, endangered and threatened species, and large numbers of 

nesting seabirds. Most of these islands are low-lying and therefore potentially vulnerable to increases in global average sea level. The potential for NWHI habitat loss 

was recently assessed by the NMFS Pacific Islands Fisheries Science Center, by creating topographic models of several islands and atolls in the NWHI and evaluating 

the potential effects of sea-level rise by 2100 under a range of basic passive flooding 

scenarios. Projected terrestrial habitat loss varied greatly among islands: 3 percent 

to 65 percent under a median scenario (48-cm rise), and 5 percent to 75 percent 

under the maximum scenario (88-cm rise). Spring tides may repeatedly inundate all 

land below 89 cm (median scenario) and 129 cm (maximum scenario) in elevation. 

Sea level is expected to continue increasing after 2100, which would have greater 

impact on atolls such as French Frigate Shoals and Pearl and Hermes Reef, where 

virtually all land is less than 2 m above sea level. Higher islands such as Lisianski, 

Laysan, Necker, and Nihoa may provide longer-term refuges for species. The effects 

of habitat loss on NWHI biota are difficult to predict, but may be greatest for endangered Hawaiian monk seals, threatened Hawaiian green sea turtles, and the endangered Laysan finch at Pearl and Hermes Reef. 

Ocean Acidification 

The oceans are the largest natural long-term reservoir for carbon dioxide, absorbing approximately one-third of the carbon dioxide added to the atmosphere by 

human activities each year. Over the past 200 years the oceans have absorbed 525 

billion tons of carbon dioxide from the atmosphere, or nearly half of the fossil fuel 

carbon emissions over this period. Over the next millennium, the global oceans are 


mura.eps
13 

expected to absorb approximately 90 percent of the carbon dioxide emitted to the 

atmosphere.12

For over 20 years, NOAA has participated in decadal surveys of the world oceans, 

documenting the ocean’s response to increasing amounts of carbon dioxide being 

emitted to the atmosphere by human activities. These surveys confirm that oceans 

are absorbing increasing amounts of carbon dioxide. Estimates of future atmospheric and oceanic carbon dioxide concentrations, based on the Intergovernmental 

Panel on Climate Change emission scenarios and general circulation models, indicate that by the middle of this century atmospheric carbon dioxide levels could 

reach more than 500 parts per million (ppm), and near the end of the century they 

could be over 800 ppm. This would result in a surface water pH decrease of approximately 0.4 pH units as the ocean becomes more acidic, and the carbonate ion concentration would decrease almost 50 percent by the end of the century. To put this 

in historical perspective, this surface ocean pH decrease would be lower than it has 

been for more than 20 million years.13

Recent studies indicate that such changes in water chemistry, or ocean acidification as the phenomenon is called, would have effects on marine life, such as corals 

and plankton.13, 14 The carbonate chemistry of seawater has a direct impact on the 

dissolution rates of calcifying organisms (coral reefs and marine plankton). As the 

pH of the oceans decreases and becomes more acidic, some species of marine algae 

and plankton will have a reduced ability to produce protective calcium carbonate 

shells. This makes it more difficult for organisms that utilize calcium carbonate in 

their skeletons or shells to build and maintain their structures. These organisms 

form the foundation of the food chain, upon which other marine organisms feed. Decreased calcification may also compromise the fitness or success of these organisms 

and could shift the competitive advantage toward organisms not dependent on calcium carbonate. Carbonate skeletal structures are likely to be weaker and more susceptible to dissolution and erosion. There is paleooceangraphic evidence that during 

the last high CO2 regime (55 million years ago) increased ocean acidification was 

associated with mass extinctions of phytoplankton species, followed by a recovery 

period of about 80,000 years.15 Because of the importance of phytoplankton to marine food webs, biodiversity and productivity of the oceans may be altered 14, which 

may result in adverse impacts on fishing, tourism, and other economies that rely 

on the continued health of our oceans. 

Recent findings indicate that such conditions could develop within decades at high 

latitudes.14 This will likely have impacts on high latitude ecosystems because 

pteropods, a shelled, swimming mollusk, is a significant prey item for fish in these 

regions. It is important to gain a better understanding of how ocean chemistry and 

biology will respond to higher carbon dioxide conditions so that predictive models 

of the processes and their impacts on marine ecosystems can be developed. 

Coral Bleaching Events 

Coral reef ecosystems are among the most diverse and biologically complex ecosystems on Earth and provide resources and services worth billions of dollars each 

year to the United States economy and economies worldwide. Coral reefs support 

more species per unit area than any other marine environment, including about 

4,000 species of fish, 800 species of hard coral and thousands of other species. Approximately half of all federally-managed fish species depend on coral reefs and related habitats for a portion of their life cycles. The National Marine Fisheries Service estimates the annual commercial value of U.S. fisheries from coral reefs is over 

$100 million. Local economies also receive billions of dollars from visitors to reefs 

through diving tours, recreational fishing trips, hotels, restaurants, and other businesses based near reef ecosystems. In the Florida Keys, for example, coral reefs attract more than $1.2 billion annually from tourism. In addition, coral reef structures 

buffer shorelines against waves, storms and floods, helping to prevent loss of life, 

property damage and erosion. 

Coral reefs are extremely vulnerable to increased sea surface temperatures. As 

global temperatures have risen over the past 30 years, there has been a corresponding increase in the extent and frequency of extremely high sea surface temperatures and coral bleaching events in many tropical regions.4, 16

Coral bleaching is a response of corals to unusual levels of stress primarily 

thought to be associated with light and ocean temperature extremes. Bleaching occurs when corals expel their symbiotic algae and lose their algal pigment. Loss of 

the symbiotic algae leaves the coral tissue pale to clear and, in extreme cases, 

causes a bleached appearance. Corals often recover from mild bleaching. However, 

if the stress is prolonged and/or intense, the corals may die or weaken, causing them 

to be more susceptible to disease and other stressors. 

14 

Coral bleaching has occurred in both small localized events and at large scales. 

Although many stressors can cause bleaching, mass bleaching events have almost 

exclusively been linked to unusually high ocean temperatures. There is still much 

that we do not know about the impacts of bleaching-associated mass coral mortality 

on: (1) the function of coral reef ecosystems; (2) the associated fisheries; and (3) the 

value (loss) to recreation and tourism industries. 

Through satellite and in situ monitoring of thermal stress, NOAA tracks the conditions that may lead to coral bleaching. When the data show that conditions are 

conducive to bleaching, NOAA provides watches, warnings, and alerts to users 

throughout the globe through NOAA’s Coral Reef Watch project and Integrated 

Coral Observing Network. Coral bleaching alerts allow managers and scientists to 

deploy monitoring efforts which can document the severity and impacts of the 

bleaching to improve our understanding of the causes and consequences of coral 

bleaching. 

Large scale or mass bleaching events were first documented in the eastern Pacific 

in the early 1980s in association with the El Nin ̃ o Southern Oscillation.16 In 1997– 

1998, coral bleaching became a global problem when a strong El Nin ̃ o (period of 

warmer than average water temperature), followed by a La Nin ̃ a (period of colder 

than average water temperature) caused unprecedented coral bleaching and mortality world-wide.17

However, coral bleaching events are not only tied to the El Nin ̃ o/La Nin ̃ a phenomena. In 2005, a year lacking El Nin ̃ o or La Nin ̃ a climate patterns, unusually 

warm temperatures were recorded in the tropical North Atlantic, Caribbean, and 

Gulf of Mexico. Corals in the Caribbean region experienced temperatures in 2005 

that greatly exceeded any of the previous 20 years. While the thermal stress in the 

Caribbean has increased over the last 20 years, 2005 was a major anomaly from 

the upward trend in temperatures there. As a result of NOAA satellite and in situ 

monitoring, we were able to alert managers and scientists to this temperature 

anomaly. The unusually warm temperatures gave rise to the most intense coral 

bleaching event ever observed in the Caribbean. NOAA is working with local partners in Florida, Puerto Rico and the U.S. Virgin Islands to better assess the impacts 

from the 2005 bleaching event. It is clear that mass bleaching is a serious concern 

to the communities that depend upon these resources. 

Preliminary analyses by NOAA show that the cumulative thermal stress for 2005 

was 50 percent larger than the cumulative stress of the prior 20 years combined.18

September 2005 was by far the warmest September in the Eastern Caribbean in the 

entire 100-year record. Many areas, including the U.S. Virgin Islands, averaged over 

90 percent of their corals bleached and some have already lost 30 percent of these 

corals due to direct thermal stress or subsequent disease. NOAA is currently analyzing the impact of this bleaching event on already vulnerable elkhorn and 

staghorn coral species. These two species have been proposed for listing as ‘‘threatened’’ under the Endangered Species Act. 

NOAA and the Department of the Interior (DOI) are leading the interagency effort of the U.S. Coral Reef Task Force to respond to and assess the massive coral 

bleaching event in the Caribbean region in 2005. This effort has engaged many government and non-government partners from across the region to assess the impacts 

of the massive event and make recommendations on how to prepare for and address 

future events. For example, NOAA, DOI, and the National Aeronautics and Space 

Administration (NASA) conducted missions in October and December 2005 to examine the extent of bleaching and recovery/mortality of corals within the Buck Island 

Reef National Monument, as well as obtain aerial and hyperspectral imagery to 

quantify the extent of bleaching within St. Croix, St. John, and southwestern Puerto 

Rico. Initial findings indicate that in many areas, including the U.S. Virgin Islands, 

over 90 percent of coral cover had bleached. While some recovery had occurred by 

December, hardest hit areas have already had over 30 percent of their coral die. 

Further analyses are currently underway. 

Impacts of Climate on Fisheries and Protected Resources 

NOAA has stewardship responsibilities for coastal and living marine resources 

from over 90 Acts of Congress. Resources managed under these authorities are extremely valuable to the country, with fisheries alone contributing over $60 billion 

a year and 520,000 jobs to the U.S. economy. Interannual climate variability (e.g., 

El Nin ̃ o, La Nin ̃ a) and trends (e.g. global warming) can cause profound geographic 

shifts in marine ecosystems and are of great consequence to fishery-dependent communities. Climate variability/change impacts environmental conditions on multiple 

time scales, ranging from interannual to decadal; since Earth’s temperature is 

warming on a global scale, it is important to assess the environmental impacts on 

large marine ecosystems. 

15 

In the past several decades, there have been significant changes in the distribution, growth, and abundance of living marine resources resulting from changes in 

ocean temperatures and related ocean conditions. These changes have occurred in 

polar regions, in temperate waters, and in the tropics. These changes have altered 

the productivity and structure of marine food webs and change the flow of goods 

and services to coastal communities. Below are cited some specific examples of ecosystems changes documented by NOAA that are likely linked to climate variations. 

Polar Regions: Loss of sea ice at high latitudes has been documented in a number 

of recent scientific articles and other forums. Until recently, the northern Bering 

Sea ecosystem had extensive seasonal sea ice cover and high water column and sediment carbon production. Recently, NOAA researchers and other colleagues have 

demonstrated that these ecosystems are shifting away from these characteristics.2, 19

The amount and duration of ice coverage in the southeast Bering Sea has decreased 

substantially since the early 1970s. In addition, the southeast Bering Sea has 

warmed 2–3°C over the past 10 years. Recent work has documented differences in 

ice coverage and thickness as far north as St. Lawrence Island in the northern Bering Sea. These changes have substantial impacts to both arctic and subarctic marine 

species in the area. For example, Greenland turbot, a flatfish that prefers cold temperatures, has shown a steady decrease in abundance since the mid-1970s. During 

this same time period, abundance of walleye pollock, which prefers warmer waters, 

has increased dramatically, with the present landings valued at $295 million per 

year. Bering Sea snow crab distribution has shifted northward, and pollock distribution in the Bering Sea may soon follow, affecting ecosystem interactions, fishery assessment surveys and the economics of the fishing fleet which have to travel farther 

and spend more days at sea to find and capture the same number of fish. In addition, juvenile pollock act as forage fish in this ecosystem and changes in their abundance, size, or distribution has the potential to affect marine mammals. 

Changes in the Bering Sea marine mammals have also been observed. Gray 

whales have shifted their distributions northward, apparently in response to decreases in sea ice and declines in their preferred prey on the ocean floor.20 In addition, ice-dependent seals (ring, spotted, bearded, and ribbon seals) require ice for 

parts of their life history (molting and pupping) and there is concern that these animals are being forced away from suitable feeding grounds as the ice retreats.21

Similar concerns have been expressed regarding polar bear and walrus populations 

in Alaska.21, 22 These changes to the ecosystem have clear implications for subsistence harvests in Alaskan native communities. 

In addition to the effects of climate variability and change on the distribution and 

abundance of commercially important species of fish and shellfish, as well as marine 

mammal species important to subsistence hunters, the reduction in the extent and 

duration of sea ice in the Bering and Chukchi Seas in recent years has led to serious 

erosion problems for several remote villages and towns, including Barrow, Pt. Lay, 

Wales, and particularly in the village of Shishmaref. In these villages, traditionally 

the sea ice would buffer the impacts of storm driven waves during the winter and 

spring. With less sea ice, wave action is causing serious erosion problems and 

threatening buildings and roads. To better predict the likely rate at which erosion 

will impact this area, requires better information on trends in sea level height, extent and duration of sea ice, and storm frequency. 

Decreases in sea ice appear to be affecting other ecosystems as well. The annual 

air temperature near the South Shetland Islands, Antarctica has warmed by over 

4°C since the 1940s 23 and ice extent around areas of Antarctica monitored by 

NOAA has declined appreciably.24 Air temperatures at Palmer station are closely 

correlated with the annual amount of ice cover. While air temperatures in the Shetlands have increased, the density of krill, a shrimp-like organism that is the central 

link in the Antarctic food web has decreased by more than 90 percent in the region 

since 1976.25 Warming of Antarctic waters and loss of ice affect predator (seals, penguins, whales, etc.) and krill populations in the Southern Ocean in several ways. 

Krill are a keystone species in the Antarctic because so many species (fish, seals, 

penguins, sea birds, whales) feed upon them. Declines in krill populations will negatively affect populations of krill predators. Over the past two decades, populations 

of Adelie and chinstrap penguins have declined significantly on the Antarctic Peninsula, and the average reproduction rate of fur seals in the South Shetlands has 

slowed as well. Years of low sea ice appear to be associated with low krill production 

but relatively high populations of salps (a gelatinous zooplankton, of little nutritional value to krill predators).5 In addition, some predators are dependent upon sea 

ice to haul out and rest during the over-wintering migrations, and declines and 

shifts in sea-ice will impact their movements and distributions. Thus, climate-related changes in the environment of Antarctica have had and will likely continue 

to have important consequences for the marine ecosystems of the region. 

16 

Temperate Regions: Climate-induced shifts in species distribution and abundance 

have been observed in the temperate regions of the Atlantic and Pacific. Many marine fish species have been observed to shift their distributions northward in response to warming waters.3, 26 Populations of surf clams, an economically important 

species along the mid-Atlantic coast of the United States (particularly from New 

Jersey to Virginia), show evidence of increased mortality in the southern regions of 

their territory. This is thought to be due to elevated sea temperatures.27 These populations are also susceptible to low oxygen events that may increase in frequency 

and severity with the anticipated warming in the Mid-Atlantic region. A severe low 

oxygen event off New Jersey in 1976 caused economic losses of over $70 million to 

the clam fishery and it was many years before the clam populations recovered.28 Declining recruitment levels of some species linked to cooler water temperature (e.g., 

yellowtail flounder in Southern New England) impedes rebuilding of the stock to 

provide long-term sustainable fisheries. 

In the western North Atlantic, a study of the distribution patterns of three dozen 

pelagic and demersal fish species was conducted using consistent data from over 

three decades to examine impacts of water temperature changes on geographic distributions.25 This study revealed a set of species whose center of distribution shifts 

from 0.5–0.9 degrees of latitude pole-ward for each degree Celsius of water temperature increase. Because not all species responded in this manner, there is likelihood 

that the structure of predator-prey relationships in the ecosystem would be altered 

under a scenario of long term warming of Atlantic waters.17, 24 Studies from the 

eastern Atlantic have drawn similar conclusions. In the southern North Sea, there 

has been a gradual replacement of species with primarily cold water affinities with 

ones previously associated with more southern waters.29

In the California Current ecosystem there have also been sustained shifts in the 

dominance of various fish species over the past few decades. Off California, the dominant fish fauna has shifted from cold-water species to ones of primarily warm water 

affinities. These changes have occurred gradually over a sustained two decade period, and are confounded by overfishing of many of the stocks. 

From the 1970s through the 1990s there were overall declines in the California 

fishery landings that coincided with an unprecedented period of unusually warm 

ocean conditions and a decline in ecosystem productivity.30 Changes in the survival 

of Pacific salmon appear to follow a decadal-scale cycle (the Pacific Decadal Oscillation, or PDO), with salmon survivorship being relatively high during the cool periods and low during warm periods.6 In addition the California sardine collapse in the 

1940s was driven in part by a shift to cooler conditions and a different ecosystem 

structure. Ocean sediment records indicate sardine biomass has fluctuated for centuries on time scales associated with decadal-scale shifts in the north Pacific temperature.31

Climate and weather patterns over the North Atlantic are strongly influenced by 

the relative strengths of two large-scale atmospheric pressure cells—the Icelandic 

Low and a high pressure system generally centered over the Azores in the eastern 

Atlantic. A deepening of the Icelandic Low often corresponds with a strengthening 

of the Azores High and vice versa. This see-saw pattern is called the North Atlantic 

Oscillation (NAO) and a simple index of its state is given by the difference in sea 

level pressure between the Azores and Iceland. 

When the NAO index is positive, we see an increase in westerly winds across the 

Atlantic and in precipitation over southeastern Canada, the eastern seaboard of the 

United States, and northwestern Europe.3 We also see increased storm activity 

tracking toward Europe. Water temperatures are markedly low off Labrador and 

northern Newfoundland, and warm off the United States. Conversely, when the 

NAO index is negative, we have decreased storminess, and drier conditions over 

southeastern Canada, and colder conditions over the eastern United States and 

northwestern Europe. Water temperatures are warmer off Labrador and Newfoundland, but cooler off the eastern United States. These changes in the state of the 

North Atlantic Oscillation show a tendency to persist on decadal time scales. The 

NAO was generally positive during the 1980s and 1990s but has shown a tendency 

to decrease since about the year 2000. 

Variation in the NAO has very different effects on cod recruitment on the western 

and eastern Atlantic.3 The direction of the NAO effect on cod recruitment exhibits 

patterns consistent with the regional manifestation of the NAO in the North Atlantic, with a coherence in the NAO effect in northern Canada and Iceland and between southern Canada-United States and western Europe. The decline in cod in 

areas such as the North Sea has been linked to the interplay of over-exploitation 

and changes in the planktonic ecosystem affecting the food supply of larval cod 

(which is in turn affected by the NAO). Specifically, the supply of the copepod 

17 

Calanus finmarchicus declined during positive NAO conditions and was replaced by 

smaller bodied species, apparently less suitable as food for larval cod. 

In the Northwest Atlantic, researchers have suggested a linkage between oceanographic conditions related to the North Atlantic Oscillation, abundance of the 

copepod Calanus finmarchicus, and the calving success of the endangered right 

whale in Gulf of Maine.32

Abundance of adult Calanus declined with these water mass changes and a concomitant decline in the birth rate of right whales was observed. The decline in the 

calving success comes at a time when other human impacts such as ship strikes 

threaten recovery of this species. These observations suggest that climate-induced 

changes can have far reaching ramifications for commercially important fish species 

throughout the North Atlantic and for critically endangered marine mammal species. 

These examples of climate-related effects on marine ecosystems are just a sample 

from the growing body of evidence linking climate change to marine ecosystem function. All of these changes, whether trended or variable over some time scale, may 

have profound implications for the health and viability of marine ecosystems and 

for the human communities that are dependent upon them. It is our challenge to 

understand these linkages both to better predict their effects and to identify the conservation and management policies in the face of climate variability and change 

that may help to mitigate their effects. 

Various management authorities have responded. For example, the Pacific Fisheries Management Council routinely takes into account decadal-scale changes in 

marine productivity regimes when setting harvest policies for Pacific groundfish and 

other species. Similar management responses are being used or contemplated in 

other living marine resource arenas in which NOAA participates. 

Ongoing Challenges for Improving Climate and Ecosystems Information 

Marine ecosystems and their component parts have proved to be sentinels of climate change and ocean variability. Changes in living marine resources, when observed at proper scales, give us new information about how changes in climate are 

affecting the Earth, and have opened new avenues of research into understanding 

the importance of human activities contributing to these observed changes. It is 

vital that we improve our understanding of past, current and projected ecosystem 

impacts of climate change in order to improve the stewardship of these resources. 

Management policies we use in living marine resource management can either help 

mitigate or exacerbate changes due to impacts of climate variation. Below I detail 

a few of NOAA’s scientific priorities in improving the predictability of ecosystem responses to climate change. 

Regional Climatologies 

Regional impacts of climate variability and change are important and are being 

studied. In fact, some region-specific modeling predicts that part of the planet—and 

the marine environment—will experience cooler and/or wetter conditions, while 

other areas will be hotter and drier. Therefore, regional ecosystem responses may 

result in stable or increasing resources in one region while at the same time resulting in declines in abundance and distribution shifts elsewhere. 

Understanding these regional impacts on marine and associated terrestrial ecosystems will require more detailed regional models and data linking global climate 

variations to regional atmospheric and ocean conditions. This requirement is consistent with NOAA’s focus over the last 5 years to integrate multidisciplinary research at the Large Marine Ecosystem level. Eight such marine ecosystems have 

been recognized in the U.S. Exclusive Economic Zone. It is at the ecosystem scale 

where we expect to be able to fully realize how anthropogenic effects (e.g., fishing, 

land use practices, pollution) and naturally driven environmental variation combine 

to produce the current abundance levels and composition of species in each of our 

marine ecosystems. 

The following will help improve our understanding the ecosystem consequences of 

climate change: 

Improved Climate and Ecosystem Modeling 

Extreme weather events as well as long term trends in atmospheric and ocean 

conditions necessitate that we further improve our predictive understanding of the 

climate system and its impacts on ecosystems. To do so, NOAA believes that expanded Earth and ecosystems modeling could serve as a tool for studies of: (1) the 

impacts of climate variability and change on land ecosystems, ocean ecosystems and 

carbon cycling; (2) the strength of ecological and carbon feedbacks on climate (e.g. 

the effects of increasing atmospheric carbon dioxide on plant growth, which in turn 

affects distributions of atmospheric carbon dioxide); and (3) improved predictions of 

18 

the impacts of climate trends on regional large marine ecosystems and their species. 

An expanded Earth and ecosystems model capability would take advantage of the 

current suite of weather, air quality, climate variability, and ecosystem models to 

include biogeochemical cycling, dynamic vegetation, atmospheric chemistry, and anthropogenic forcing (e.g. carbon and aerosols) of climate. Existing hydrodynamic 

models of ocean circulation would be expanded to include trophic interactions, primary productivity, and spatial distributions and movement models for specific taxa, 

among other ecological phenomena. It would employ a unified modeling framework, 

enabling integration of a comprehensive suite of physics, assimilation, biogeochemical, and ecosystem model components. 

As model development progresses, components will be expanded to include: (a) a 

land model (currently under evaluation) that simulates dynamic land vegetation and 

land use changes, as well as the exchange of water and energy between land, vegetation, and atmosphere; (b) a comprehensive ocean biogeochemical model (under refinement) and (c) state-of-the-art marine ecological models incorporating ocean circulation and spatially explicit processes. 

Comprehensive Earth-ecosystems models have a wide range of applicability for 

managers of marine ecosystems, including: 

• Short term (6 months to 1 year) and medium term (2–5 year) projections of the 

regional response of fisheries and protected species to climate change 

• Seasonal-interannual prediction of the abundance and distribution of marine 

populations; 

• Seasonal forecasting of coral bleaching potential and assessment of the longterm impact of climate variability and change on coral bleaching frequency; 

• Assessments of the health of coastal ecosystems under the stress of pollution 

and runoff; 

• Predictions of harmful algal blooms and eutrophication zones; 

• Identification of impact of climate change on species diversity; 

• Analysis relating to land use practices and climate; 

• Design of marine protected areas and other management measures; 

• Predictions of pollution transport and effects on human health; and 

• Understanding seasonal patterns of plant reproduction and animal migration. 

In order to develop these integrated regional and global models of ecosystem response, we face a number of technical challenges. Additional research to provide the 

information needed to understand the underlying processes linking climate change 

to the response of living marine resources is critical. Many of the examples of ecological response cited above are based on statistical correlations of time series of environmental data rather than a fundamental understanding of the complex relationships responsible for the observed phenomena. Predictive models must take such 

complex dynamics into account. Expanded ecosystem research capabilities will be required to assess these critical links. At the same time, expanded modeling capabilities will require more comprehensive physical observations and related routine monitoring data than we have the capability to deploy today. 

Importance of the Integrated Ocean Observing System 

NOAA has a large, broad-scale and robust system of oceanographic, climate, and 

ecosystem measurement stations throughout the U.S. EEZ and the world. To make 

data from these systems available to climate and ecosystem scientists both within 

the U.S. and globally, NOAA is working with other Federal agencies and academic 

and State partners to build the U.S. Integrated Ocean Observing System (IOOS). 

IOOS, when fully integrated, will provide more complete and improved access to observations of the oceans, including ecological and physical parameters linked to climate variability and change and requisite social and economic information, to serve 

multiple societal goals. IOOS will support regional climatologies and will provide information necessary to model climate impacts on ecosystems at appropriate global, 

regional, and local scales. Full development of IOOS is a high priority in understanding climate effects on U.S. marine ecosystems, and contributes to U.S. support 

of the Global Earth Observing System of Systems (GEOSS). 

Management of Living Marine Resources using Ecosystems Approaches 

Our current understanding of climate impacts on marine ecosystems points to the 

critical need to employ ecosystem-based approaches to monitoring, assessing, and 

managing living marine resources. Climate change is only one of a complex set of 

factors (both human-induced and naturally-occurring), that influence living marine 

resources. These include harvesting policies for fisheries, protected species recovery 

19 

policies, and management of increasingly complex uses of the coastal zone for a variety of other societal needs. Effective management of resources in this complex environment means we will have to balance many competing and simultaneous objectives. NOAA is committed to advancing an ecosystem approach to its many stewardship responsibilities as a way forward in striking this balance. NOAA defines an 

ecosystem approach to managing living resources is one that is geographically specified, collaborative, adaptive, accounts for the broad scope of ecosystem knowledge 

and uncertainties, considers multiple factors affecting resources, is incremental in 

approach, and balances diverse societal objectives. Incorporating the effects of climate change into the conservation of living marine resources is one of the Nation’s 

greatest and most critical challenges facing ocean ecosystems management. 

Thank you Mr. Chairman, I would be pleased to answer any questions you or the 

other Committee members may have. 

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2005, Highly variable Northern Hemisphere Temperatures Reconstructed from Lowand High-Resolution Proxy Data, Nature, 433: 613—617. 11Finney, B. P., I. Gregory-Eaves, M. S. V. Douglas, and J. P. Smol, 2002, Fisheries productivity in the northeastern Pacific Ocean over the past 2,200 years, Nature, 416: 729–733. 12 Archer, D. E., H. Kheshgi, E. Maier-Reimer, 1998, Dynamics of fossil fuel CO2

neutralization by marine CaCO3, Global Biogeochemical Cycles, 12: 259–276. 13Feely, R. A., C. L. Sabine, K. Lee, W. Berrelson, J. Kleypas, V. J. Fabry, and 

F. J. Millero, 2004, Impact of anthropogenic CO2 on the CaCO3 system in the 

oceans, Science, 305(5682): 362–366. 14Orr, J. C., V. J. Fabry, O. Aumont, L. Bopp, S. C. Doney, R. A. Feely, A. 

Gnanadesikan, N. Fruber, A. Ishida, F. Joos, R. M. Key, K. Lindsay, E. MaierReimer, R. Matear, P. Monfray, A. Mouchet. R. G. Najjar, G.-K. Plattner, K. B. Rodgers, C. L. Sabine, J. L. Sarmiento, R. Schlitzer, R. D. Slater, I. J. Totterdel, M.- 

F. Weirig, Y. Yamanaka, and A. Yool, 2005, Anthropogenic ocean acidification over 

the twenty-first century and its impact on calcifying organisms, Nature, 437: 681– 

686. 15Zachos, J. C., U. Ro ̈hl, S. A. Schellenberg, A. Sluijs, D. A. Hodell, D. C. Keely, 

E. Thomas, M. Nicolo, I. Raffi, L. J. Lourens, H. McCarren, and D. Kroon, 2005, 

Rapid acidification of the ocean during the Paleocene-Eocene thermal maximum, 

Science, 308: 1611–1615. 16 Brown, B. E., 1997, Coral bleaching: causes and consequences, Coral Reefs 

16(5): S129-S138. 17Wilkinson, C. R., 2000, Status of Coral Reefs of the World: 2000. Townsville, 

Australia, Australian Institute of Marine Science. 

20 

18 Eakin, C. M. et al., 2006, Record-Setting Coral Bleaching the Result of Thermal 

Stress, intended for Science, in preparation. 19Overland, J. E., and P. J. Stabeno, 2004, Is the climate of the Bering Sea warming and affecting the ecosystem? EOS Trans. Am. Geophys. Union, 85(33): 309–316. 20Moore, S. E., J. M. Grebmeier, and J. R. Davies, 2003, Gray whale distribution 

relative to forage habitat in the northern Bering Sea: current conditions and retrospective summary, Can. J. Zool., 81: 734–742. 21Tynan, C.T., and D.P. DeMaster, 1997, Observations and predictions of arctic 

climate changed: potential effects on marine mammals, Arctic, 50: 308–322. 22Stirling, I., Lunn, N.J., and Iacozza, J. 1999. Long-term trends in the population ecology of polar bears in western Hudson Bay in relation to climatic change. 

Arctic 52: 294–306. 23Smith, R. C. and S. E. Stammerjohn, 2001, Variations of surface air temperature and sea-ice extent in the western Antarctic Peninsula region, Ann. Glaciol., 33: 

493–500. 24 Hewitt, R. P. and E. H. Linen Lowe, 2000, The Fishery on Antarctic Krill: Defining an ecosystem approach to management, Rev. Fish. Sci., 8(3): 235–298. 25 Atkinson, A., V. Siegel, E. Pakhomov, and P. Rothery, 2004, Long-term decline 

in krill stock and increase in salps within the Southern Ocean, Nature, 432: 100– 

103. 26Murawski, S. A., 1993, Climate change and marine fish distributions: Forecasting from historical analogy, Trans. Am. Fish. Soc., 122: 647–658. 27Weinberg, J.R., T.G. Dahlgren, and K.M. Halanych. 2002. Influence of rising sea 

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Bethesda, MD. 28Swanson, R. L. and C. J. Sinderman, 1979, Oxygen depletion and associated 

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24–40. 32Greene, C. H., A. J. Pershing, R. D. Kenney, and J. W. Jossi, 2003, Impact of 

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Senator VITTER. Thank you very much, Doctor. 

We also have, as I said, Dr. Armstrong. Thank you for being 

here, as well, Doctor, and please proceed with your testimony. 

STATEMENT OF DR. THOMAS R. ARMSTRONG, PROGRAM 

COORDINATOR, EARTH SURFACE DYNAMICS PROGRAM, U.S. 

GEOLOGICAL SURVEY, DEPARTMENT OF THE INTERIOR 

Dr. ARMSTRONG. OK. Mr. Chairman and members of the Subcommittee, thank you for the opportunity to participate in today’s 

hearing. 

I am Dr. Thomas Armstrong, Program Coordinator for the Earth 

Surface Dynamics Program at the U.S. Geological Survey. I also 

represent USGS in the Department of the Interior with the U.S. 

Climate Change Science Program and the Climate Change Working 

Group of the Arctic Monitoring and Assessment Program. 

The USGS strives to understand how the Earth works and to anticipate changes in how the Earth functions. To accomplish this, 

USGS science aims to understand the interrelationships amongst 

Earth’s surface processes, ecological systems, and human activities. 

This includes understanding current changes in the context of prehistoric and recent Earth processes, distinguishing between natural 

21 

and human-induced changes, and recognizing ecological and physical responses to changes in climate. 

The scientific community is largely in agreement that human activity in the 20th and 21st centuries has enhanced greenhouse gas 

concentrations in the atmosphere and has affected global temperature and climate. But climate change is also a natural, continuous, 

inevitable Earth process that has occurred throughout Earth’s history. Natural climate change is influenced by many forces, one of 

which is concentration of both naturally-emitted and human-induced greenhouse gases into the atmosphere. In fact, natural climate change has occurred on a regular basis on this planet for millions of years. 

Paleoclimate research conducted at USGS and elsewhere has 

shown that the Earth has experienced several episodes of global 

warming in the last 800,000 years, during which air temperatures 

and levels of CO2 increased in ways comparable to present changes. 

By studying various parameters or proxies in the prehistoric 

record, such as tree rings, ice cores, and fossil records, scientists at 

USGS and elsewhere have developed a detailed record of prehistoric climate change, including changes in temperature and atmospheric CO2 concentrations over the last several hundred-thousand years. This record shows that natural climate change is generally cyclical in nature, with 40,000- to 50,000-year-long cycles of 

global cooling and glaciation, punctuated by, typically, 10,000-to 

15,000-year-long cycles of global warming and deglaciation, which 

are often called interglacial periods. 

The general consensus among climate scientists is that we are 

now in an interglacial period with related global warming. 

One of the major challenges facing the climate science community today is distinguishing natural change from change imposed 

upon the natural system through human activities. Although the 

prehistoric climate record includes temperature conditions comparable to those today, ice core records and other recent scientific 

findings show that the current concentrations of CO2 in the atmosphere are now higher than at any time in human existence or in 

the prehistoric record. This trend suggests a significant excursion 

from the prehistoric natural climate record that may lead to unprecedented climatic conditions in the future. A better understanding of the causes of this change is necessary before scientists 

can differentiate between the natural and human-influenced components of present climate change, as well as the potential influence of human activities on future global climate. 

Understanding the processes and distinguishing natural variability from human-influenced change is just the first step toward 

success in the field of climate change. Equally important is effectively communicating climate science to the rest of the world. 

Scientists must relay the information, analyses, and, more importantly, conclusions to policymakers, resource managers, and the 

general public in ways that are both easy to understand and useful. 

In addition, and very important, scientific findings related to climate change must be delivered in a timely manner so that decisionmakers will be informed by the most relevant, up-to-date, objective information possible. Furthermore, scientists must provide 

this information with very accurate estimates of uncertainty so 

22 

that conclusions and recommendations drawn from scientific studies can be properly evaluated. 

The climate science community continues to struggle with development of a consensus on the specifics of the long-term climate future for our planet, but, as we continue to conduct well-planned 

science to make progress on defining natural climate change and 

to better distinguish natural from human-influenced climate 

change, we will gain a fuller and more useful understanding of how 

climate has changed in the past, how it occurs today, and how it 

may occur in the future under different sets of human-influenced 

scenarios. 

Thank you, Mr. Chairman, for the opportunity to present this 

testimony, and I will be pleased to answer any questions you and 

the other Members of the Subcommittee may have. 

[The prepared statement of Dr. Armstrong follows:] 

PREPARED STATEMENT OF DR. THOMAS R. ARMSTRONG, PROGRAM COORDINATOR, EARTH SURFACE DYNAMICS PROGRAM, U.S. GEOLOGICAL SURVEY, DEPARTMENT OF

THE INTERIOR

Mr. Chairman and Members of the Subcommittee, thank you for the opportunity 

to participate in this hearing on climate change and its effects on terrestrial and 

marine systems. My name is Tom Armstrong, and I am the Program Coordinator 

for the Earth Surface Dynamics Program at the U.S. Geological Survey (USGS). I 

also represent USGS and the Department of the Interior as a member of the U.S. 

Climate Change Science Program and the Climate Change Working Group of the 

Arctic Monitoring and Assessment Program. 

The USGS strives to understand how the Earth works and to anticipate changes 

in how the Earth functions. To accomplish this, USGS science aims to understand 

the interrelationships among Earth surface processes, ecological systems, and 

human activities. This includes understanding current changes in the context of prehistoric and recent Earth processes, distinguishing between natural and human-influenced changes, and recognizing ecological and physical responses to changes in 

climate. 

We conduct scientific research in order to understand the likely consequences of 

climate change, especially by studying how climate has changed in the past and 

using the past to forecast responses to shifting climate conditions in the future. My 

testimony today will address three major sets of challenges: 

1. Distinguishing natural from human-influenced climate change; 

2. Understanding ecological and physical responses to climate change, and predicting the related impacts of these responses on climate; and 

3. Effectively conveying cutting-edge climate science to policy-makers, decisionmakers, and the public. 

I will conclude my testimony with a brief discussion of the state of our understanding of climate science and how this provides a roadmap to our future understanding of long-term climate change and its impact on people, natural resources, 

and the Earth. 

Distinguishing Natural from Human-influenced Climate Change 

In a statement on behalf of the Administration to the Senate in July, 2005, Dr. 

James R. Mahoney, now former Assistant Secretary of Commerce for Oceans and 

Atmosphere, and Director of the U.S. Climate Change Science Program, stated, ‘‘We 

know that an increase in greenhouse gases from the use of energy from fossil fuels 

and other human activities is associated with the warming of the Earth’s surface.’’ 

This statement underlies the growing public debate on climate change: are humans 

and their activities the driving force behind global warming? The scientific community is largely in agreement that human activity in the 20th and 21st centuries has 

enhanced greenhouse gas concentrations in the atmosphere, and these added gases 

have an effect on global temperatures and climate. Climate change is also a natural, 

continuous, inevitable Earth process that is influenced by many forces, one of which 

is the concentration of both naturally-emitted and human-induced greenhouse gases 

in the atmosphere. Many other forces also control climate change, including cyclical 

changes in solar radiation, movement of the Earth’s tectonic plates, oscillations in 

23 

ocean temperatures and ocean currents, and the positions and magnitudes of meteorological entities such as high, low, and convergent zones. In fact, natural climate 

change has occurred on a regular basis on this planet for at least the last 800,000 

years and possibly much longer. Paleoclimate research has shown that the Earth 

has experienced several episodes of global warming in this timeframe during which 

air temperatures and levels of CO2 increased in ways comparable to the present day 

changes, although the ice record indicates that the current concentrations of CO2

in the atmosphere are unprecedented during human existence. Understanding the 

science of natural variability in climate is essential to the formation of effective policy regarding the mitigation of or adaptation to climate change, both human and 

natural. 

One of the major challenges facing the climate science community is distinguishing natural climate change from that imposed upon the natural system 

through human activities. This science must also develop an effective understanding 

of the consequences of the human-induced component. The science we conduct in 

order to understand both the human component of climate change and its potential 

impacts on the natural climate system is known as climatology; paleoclimatology 

looks into the prehistoric past of the Earth in order to determine how climate 

change occurred prior to human activity. Through paleoclimate studies, scientists 

have been able to determine that climate changes naturally, and that there indeed 

are natural climate cycles that have occurred regularly, and in a predictable fashion, 

over at least the last 800,000 years of Earth history. 

By studying various parameters, or proxies, in the prehistoric record, such as treerings, ice-cores, and fossil pollen records, scientists at USGS and elsewhere have 

been able to develop a detailed record of climate change, including changes in temperature and atmospheric CO2 concentrations over the last several hundred thousand years (Figure 1). This record shows that natural climate change predates 

human influence and is generally cyclical in nature, with long-term periods of global 

cooling and glaciation (40,000 to 50,000) years long, punctuated by shorter-term periods of global warming and deglaciation (10,000 to 15,000 years in duration). The 

general consensus among climate scientists is that we are within a new interglacial 

period with related global warming. 

24 

Ecological and Physical Responses to Climate Change 

A second set of very important challenges relates to developing a better understanding of how the Earth and its physical and biological processes respond to climate change over the short-term and well into the Earth’s future. Scientific research conducted over the past several decades reveals that climatic changes are 

part of a larger interactive system of changes in ecosystems, oceans, glaciers, atmospheric chemistry, and many other components. The geologic record provides information on how this complex system has operated over time and clues to the potential causes of change. By looking back into the Earth’s geologic record, scientists 

have been able to determine how ecological and physical systems and processes 

change, adapt, or terminate as climate changes; and how these responses can alter 

climate (known as a feedback mechanism). Many of these climate changes are gradual and continuous, with ecological and physical responses occurring over hundreds 

or thousands of years. Some of these climate changes are abrupt, spanning decades, 

with the resulting ecological and physical changes being short-lived but very dramatic. 

Some examples of responses and feedbacks to climate change include: 

• The temperature of the United States has increased by an average of less than 

1 degree Celsius during the past 56 years, with much variation among regions. 

For example, Alaska has experienced an average warming of 4 degrees since 

1950, more than 4 times the U.S. average of 1 degree. 

• The higher the latitude, the greater the increase in temperature. Of particular 

concern are the rapid changes occurring in northern latitudes, where temperature changes have been greater than elsewhere on the globe. Permafrost is 

thawing and has the potential of releasing significant amounts of carbon dioxide 


arms.eps
25 

to the atmosphere and nutrients to the coastal ocean. Decreasing ice cover is 

exposing coastlines to rapid erosion and the Arctic Ocean to accelerated warming. The USGS and the U.S. Forest Service are initiating a multi-agency, multidisciplinary research and monitoring effort to track and understand these 

changes in the Yukon River Basin in Alaska and northwest Canada. The Yukon 

Basin will serve as a benchmark landscape for interpreting and responding to 

rapid climatic, hydrologic, and ecological changes occurring in Northern latitudes. 

• Decreased cloud cover in the northern latitudes related to climate change correlates to decreased snow levels, less solar reflection, and thus greater melting 

of snow, glacial ice and permafrost. This creates an additional feedback mechanism where more melting leads to greater atmospheric water vapor, which in 

turn leads to a warmer atmosphere. 

• Over the last 50 years, climate change in the northeast (Maine and New Hampshire) and mountain-west (Washington and Oregon) of the United States has 

led to between 8 and 17 percent declines in annual winter snow pack. The physical response to this decline includes decreased recharge of the ground-water 

systems, decreases in surface-water flows, increased stress to public water systems, changes in the timing of river ice-outs, and significant impacts on the 

spawning environments for fish such as Pacific and Atlantic salmon. 

The Effective Conveyance of Climate Science to Policy-makers, Decisionmakers, and the Public 

Scientists must relay relevant information, analyses, and conclusions to policymakers, resource managers, and the general public as a whole. Besides global 

warming, other ecological and physical consequences of climate change may include 

strong storms, sea-level rise, droughts and floods. If scientists can better inform decision-makers about what to expect from climate change, this will effectively enhance the development of short- and long-term strategies for protecting the public 

welfare and maintaining healthy and viable ecosystems and natural resources. For 

instance, studies conducted by USGS and others are showing that sea-level rise will 

continue to impact coastal zones throughout the world. Present and future resource 

managers will need to take into consideration this scientific conclusion when developing an adaptive management strategy for restoration and long-term stewardship 

of land, water, and biological resources. 

Scientific findings related to climate change must be delivered in a timely manner 

so that decision-makers are informed by the most relevant, up to date, objective information possible. Furthermore, scientists must provide this information with very 

accurate estimates of uncertainty so that conclusions and recommendations drawn 

from scientific studies can be properly evaluated. The U.S. Climate Change Science 

Program, of which USGS and the Department of the Interior are members, is actively involved in developing a more effective decision support strategy for all interested stakeholders. 

The Future of Climate Change 

Understanding the paleoclimate history—where we look at climate information 

well beyond the 50 to 100 year instrumental record—is important because it provides us a natural climate baseline from which to work. The instrumental record 

provides us only a momentary glimpse of the entire picture of past and future climate change. We need to understand what has happened in the past in order to 

forecast future short- and long-term climate trends. Once the baseline has been established we can then begin to distinguish the human-induced factors that must be 

considered. This information then allows us to validate model predictions of past climate change and use that information to develop better-constrained models to forecast the effects of future climate change, and related ecological and physical responses and feedbacks. 

For all of the information we have gathered, and for all of the understanding of 

climate change that we have developed, the climate science community continues to 

strive toward development of a consensus on the long-term climate future for our 

planet. Given our current scientific understanding of climate change, the following 

are areas in which USGS science can make a valuable contribution: 

• Determining the baseline physical, chemical, and ecological conditions of the 

Arctic and Subarctic. Without new baseline data and monitoring infrastructure, 

our ability to determine what changes are occurring in northern latitudes, and 

our capacity to help society develop cost-effective adaptations to those changes, 

may be greatly diminished. 

26 

• Developing decision support systems for the impact of sea-level rise. Current research concludes that sea level rise will continue. Since sea-level rise is already 

having impacts on some ecosystems and human communities, decision support 

systems will be critical tools for planners to anticipate levee construction or relocation of shoreline infrastructure. 

• Focusing attention on the potential changes in the most vulnerable regions and 

systems (e.g., polar regions, coastal zones, and the tropics), and assessing regional impacts of long-term climate change. 

• There might be surprises: critical thresholds in Earth and biological systems 

may be abruptly reached that have long-term or even permanent consequences. 

• Adaptation strategies can minimize negative impacts of natural climate change, 

as well as the impacts of human-induced climate change; mitigation may work 

to quell human-induced climate change and variability. 

• Although possibly successful, mitigation of natural changes may very likely lead 

to unforeseen additional problems unless the system under study is extremely 

well understood. 

Thank you, Mr. Chairman, for the opportunity to present this testimony. I will 

be pleased to answer questions you and other Members of the Subcommittee might 

have. 

Senator VITTER. Thank you both very much. 

I’ll open it up with questions, and pose this question to both of 

you. Where do 20th century measurements and trends fall in the 

very, very long-term historical record, in terms of previous natural 

historical cycles? 

Dr. ARMSTRONG. Senator, I’ll go first. 

The current conditions of temperature fit within what we see in 

terms of cycles of climate change over the last 400,000 years. We 

need to look at climate both in terms of long-term climate change 

over a long-term many thousands-of-years in order to distinguish 

various long-term natural climate cycles, but also to distinguish 

those long-term cycles from human-induced change. But temperature is a component that is on—in the realm of what we’ve seen 

in the prehistoric past. 

What is most unique, I think, is that the temperature is out of 

alignment with the present CO2 concentrations and methane concentrations that we see in the atmosphere. Those, according to the 

most recent scientific information, are at unprecedentedly high levels compared to the prehistoric past. 

Senator VITTER. Doctor? 

Dr. MURAWSKI. Just look at the shorter time cycle, the last 

10,000 year, since the last ice age. The current temperatures and 

current amount of precipitation is actually the highest levels that 

we’ve seen in the last thousand years. 

Senator VITTER. But that’s sort of one cycle. I guess what I’m 

asking is, If you look at previous historical cycles, including peaks, 

is this—fall within those boundaries, or not? 

Dr. MURAWSKI. I agree with the testimony that Dr. Armstrong 

gave, in terms of long-term cycling of—— 

Senator VITTER. Right. 

Dr. MURAWSKI.—ice ages that have come and gone. 

Senator VITTER. What would be the temperature point or line beyond which this current trend would clearly be moving beyond previous historical experience? 

Dr. ARMSTRONG. I can get the specific information for you. 

But I can say, offhand, that we are—within the uncertainties 

that we have from the geological record, we are on par for being 

27 

at the peaks of what we’ve seen in long-term climate cycles. We are 

at a peak, in terms of temperature. If it goes much higher than 

what we see today, we will be getting into that realm within the 

uncertainties of the information we have in the past, where temperatures will reach unprecedented levels. But it really—I want to 

stress, Senator, that it is the CO2 and the methane levels in the 

atmosphere that are significantly higher than what we have seen 

in the prehistoric record. 

Senator VITTER. Right. Right. But, of course, one of our biggest 

concerns about those levels is impact on temperature. 

Dr. ARMSTRONG. Correct. 

Senator VITTER. And so, that’s why I’m—— 

Dr. ARMSTRONG. That is correct. 

Senator VITTER.—asking about impact on temperature. 

Dr. ARMSTRONG. Right. And that is something that USGS science 

looks a lot at the past record, and we see that there is a coincidence between changes in greenhouses gases naturally emitted, obviously, in the prehistoric record, greenhouse gas concentrations, 

and temperature changes. They do mimic each other. What—if we 

look at the present scientific literature, the most recent information 

from ice core records and other information, there seems to be a 

disconnect now between levels of greenhouse gases, which are 

going up, compared to what we see with temperature. 

Senator VITTER. OK. Also, another pretty broad question for both 

of you. What’s each of your opinions regarding the state of science, 

in terms of climate models? Obviously, in terms of your projection 

to the future and impacts that it could have on the environment 

and animals, as well as human populations, we need to depend on 

certain models and predictions. What’s your assessment of the current state of the accuracy and fine-tuning of those models? 

Dr. MURAWSKI. We see a convergence of many global climatechange models that are being run now, and we see a general convergence in the results. In fact, there was a paper published in Nature a couple of weeks ago that looked at the various model runs 

and looked at their assumptions. And we do seem to be closing in 

on the general range of temperature increases that’ll be there. 

That being said, we know that we have to do more, in terms of 

the modeling, in terms of understanding regional impacts, because 

that’s what’s so important for the ecosystems, both terrestrial and 

in the ocean, how the regional climatologies will influence what 

goes on, because even the global models that we have now, are indicating some places will be wetter and cooler under a general rise 

in Earth’s temperature. And so, we need to understand and step 

those models down into the regional size to understand the regional ecosystem impacts better. 

Senator VITTER. And I assume—Doctor, before you answer—I assume part of this analysis of modeling is how a model predicts past 

behavior. And how do they? How do the best models we have developed to date compare, in terms of predicting past activity? 

Dr. MURAWSKI. Well, I’m not a climatologist, so I’ll pass on that 

one. We can certainly get that information back to you. 

Senator VITTER. OK. 

Doctor? 

28 

Dr. ARMSTRONG. Yes, I would actually like to go back to what Dr. 

Murawski was saying about the articles in Nature by Dr. Overpeck 

and other scientists. There are several in the journal, Nature and 

Science. One of the global circulation models that was used in this paper 

was doing just what you asked, Senator, and that was looking— 

using the current model framework and incorporating the geologic 

record, the prehistoric record into the model, and found that, as 

they put in various parameters from the past into the framework 

of this model, including starting conditions and intermediate and 

long-term conditions, they were able to mimic very well the proxy 

record or the conditions that the—you would predict, that we know 

occurred in the past, and then take that, in turn, and look toward 

the future. And I would say that’s one of the things at USGS that 

we—I would have to say are—have been critical of in the past with 

research, is that some of the research hasn’t really looked at the 

natural variability of systems as effectively as it needed to. And I 

think these papers, by Dr. Overpeck and others, are a real significant breakthrough in the use of the paleorecord in order to better 

understand or calibrate to the past to predict into the future. 

Senator VITTER. OK. 

Dr. Murawski, in your testimony you mentioned, somewhat in 

passing, that subsidence in Louisiana, which I’m obviously very interested in, is attributable to hydrocarbon recovery in coastal areas. 

I’ve talked to some experts down there who also say that there is 

long-term natural subsidence unrelated to more recent activity. 

Would you like to comment on how you think those two factors contribute, in terms of subsidence in coastal Louisiana, in particular? 

Dr. MURAWSKI. Sure. There are a lot of factors that are influencing the rate of sea-level rise there. And, of course, coastal Louisiana is the hotspot for sea-level rise throughout the country. Obviously, you’ve got the issues of the reduction in sediment coming 

down the Mississippi and other major rivers, which are contributing to the marshlands being reduced in size. You’ve got all sorts 

of exploration and production activities that are creating voids 

there, that contribute to subsidence. And then, you’ve got general 

sea-level rise. And so, it’s the mix of those three factors that’s important. And, of course, we’re trying to mitigate sea-level rise 

issues in the coastal marshes down there, because they’re so important to the marine fisheries of the Gulf area, because most of the 

species there are estuarine dependent. That means their juvenile 

nursery areas are in those marshes, and they’re so important. 

Senator VITTER. In terms of the relative significance of the various factors, do you think there is a scientific consensus about it? 

Because obviously that drives, in part, what we might do to stop 

it or mitigate it. 

Dr. MURAWSKI. Well, there has been a lot of work in trying to 

look at those relative factors, and they’re probably playing out differently in different locations. Obviously, the reduction in sediment 

load in the Mississippi over the last century has been very significant, in terms of that, but, of course, you know, in various places 

the balance of those factors may play out differently, just because 

of the nature of those activities, the very local, you know, exploration activities, et cetera. 

29 

Senator VITTER. OK, thank you. 

Chairman Stevens? 

The CHAIRMAN. In terms of looking at the long, long, long history 

of the world, what is the—sort of, the period of time that the cycles 

have taken place? One of you go back 30- to 40,000 years. How far 

back do you go, in terms of your measurements? 

Dr. ARMSTRONG. Well, the science that I was referring to, Senator, we were looking back over the geologic record 400- to 800,000 

years, and obviously the farther back you go, the less perfect the 

record, the lower our resolution, and the higher our uncertainty, 

which is important to clearly define. 

There are different cycles related to different things—orbital forcing, solar insulation. These cycles occur on time periods of cycles 

of 100,000 years, 40,000 years, 17,000 years, possibly 9,000 years. 

But these cycles combine to present what is a very regular cyclical 

pattern over that long-term geological record. 

The CHAIRMAN. If I understood Dr. Armstrong, if you compare 

the current period to the distant past, there still are some cycles 

where the highs and lows and the differences would be similar to 

what we’re—we’ve gone through in the past. Is that right? 

Dr. ARMSTRONG. That’s correct. That’s in my written testimony, 

as well, at figure 1. Absolutely so. 

The CHAIRMAN. So, we could—then we could be either at the top 

of the cycle and going up, or we could be at the top of the cycle 

and starting to turn down. 

Dr. ARMSTRONG. The—one of the problems you’ll see, even in figure 1 of my written testimony, is that if we try to telescope too 

much the instrumental record, be it 40 years or 100 years, we’re 

looking at a very short period of time in that long-term climate 

cycle. It is not much information, in terms of the long period of 

time. And without that geologic—that paleoclimate information, we 

really can’t deduce the long-term cycle. That’s why the ice core 

analyses, both from west Antarctica and Greenland, have been so 

invaluable to us in understanding long-term climate cycles, because 

those cycles are much, much longer than the instrumental record 

itself. 

The CHAIRMAN. All right. As you say—if your number-one challenge is to distinguish natural from human-influenced climate 

change, right? 

Dr. ARMSTRONG. I believe that is one of our major challenges, 

yes. 

The CHAIRMAN. What do we need to do to do that job better? 

Dr. ARMSTRONG. I think one of the things that we’ve been trying 

to do at the USGS—and I know that other people at NOAA, with 

their group on paleoclimate, and academia, are trying to develop 

better proxies or better indicators of past climate conditions, and 

certainly a better handle on age uncertainties of the climate record 

itself, so that we can have a higher resolved, more accurate understanding of when changes occurred, exactly, or as close to exactly 

we can in the geologic record, and what were the exact conditions 

that occurred, both in terms of temperature or gas concentrations 

or other valuable pieces of information, including ecological responses to climate change over the geologic record. 

30 

The CHAIRMAN. Well, Dr. Akasofu’s volcano observatory can give 

us a prediction of how soon a volcano may erupt, but we can’t get 

a prediction over a period of years ahead how often is that going 

to happen. Those are natural emissions, right? Now, do we need 

any more measurements to determine how much is natural and 

how much is manmade on—from the natural side? 

Dr. ARMSTRONG. My opinion is, yes, we do. We need more science 

that can distinguish—first, truly understand natural variability, 

natural climate change, because that baseline is not static, it is not 

flat, it is changing. It’s constantly changing. It may not change a 

lot on a daily basis or over 100 years, but at times it can be abrupt 

or it can occur dramatically over 1,000 years. Having more information on that natural baseline and how it changes and will 

change over time is critical to understanding what the additive effects of human activities are on global climate, and as Dr. 

Murawski said, on regional climate, as well. 

The CHAIRMAN. All right. Dr. Murawski, you’re more connected 

with the ocean side of this, right? 

Dr. MURAWSKI. Right. 

The CHAIRMAN. Which is two-thirds of the world’s surface, right? 

Dr. MURAWSKI. Right. 

The CHAIRMAN. Do you really think you have the ability to measure that two-thirds today? 

Dr. MURAWSKI. Well, one of our proposals, obviously, is to try to 

improve the observing that we’re doing in the ocean side through 

the Integrated Ocean Observing System and other things. We’re 

trying to take more and more physical measurements and correlate 

them with a more dense biological observing system, as well. I 

mean, we’re trying to measure things like changes in walrus distribution and whale distribution in the Bering Sea, along with the 

fish species, crab species, and other things. It’s a—— 

The CHAIRMAN. I’m a fisherman. I think the whales and mammals go where the fish are, just like we do. But I’ll put that aside. 

What do you think you need, in terms of ability to measure the 

oceans, that you don’t have? 

Dr. MURAWSKI. Well, we need a lot more dense observation network, in terms of physical measurements—basic buoys, the sea surface temperatures from satellites. Next generation, we need the 

basic tools to measure the biological processes that we’re looking 

at. They need to be more dense. They need to be distributed around 

the coasts. We have a system that’s about 50 percent built out at 

this point, in terms of measuring the various parameters, both on 

the physical—— 

The CHAIRMAN. Right. 

Dr. MURAWSKI.—side and—— 

The CHAIRMAN. Last question, I’ll—I’ve got a lot more questions, 

but I’ll only ask one more. I’m sure you’re familiar with what Dr. 

Sylvia Earl is doing with her submersibles. Are we learning anything from those submersibles, in terms of what’s happening in the 

deep sea, as compared to what’s happening on the surface? 

Dr. MURAWSKI. Well, in terms of the deep sea, obviously, you 

know, this is one of the most unexplored areas on the planet. Now, 

we have an ocean exploration project in NOAA that we’ve been trying to nip away at, understanding deep coral reefs and other 

31 

things. We’re learning that, there’s a lot more biological diversity 

down there than we have anticipated. For example, the coral gardens off Alaska, in the deep water, were unknown to science until 

we started poking around in the deep water. We definitely need a 

research program that looks not only at the coastal ocean, but the 

deeper ocean, as well. 

The CHAIRMAN. Well, I’ve just—I lie a little, that that was my 

last question. What’s the impact of changes in the deep sea, as far 

as human experience, compared to that on the surface? Is there 

anything going on down there we should—we really should be excited about? 

Dr. MURAWSKI. Well, one of the things that we need to be careful 

about is this new discovery of these deep coral gardens that we see 

in the deep oceans. Those deep cold-water corals are at risk to increasing acidification of the ocean, because those corals are formed 

by the accumulation of calcium carbonate. And if, in fact, the calcium carbonate budget of the deep ocean is going to decline, particularly in the polar areas, which some of the projections indicate, 

then they could be at risk for long-term climate change. 

The CHAIRMAN. Well, I have a bill to authorize further ocean exploration to deal with that kind of research. Unfortunately, we 

have a Senator that doesn’t want anything else new authorized, 

thinks there are too many programs already authorized. So, we’ll 

probably have to wait until we solve that problem. 

Thank you very much, Senator. 

Senator VITTER. Thank you, Mr. Chairman. 

Senator Lautenberg? 

Senator LAUTENBERG. Thanks, Mr. Chairman. 

I’m sorry I didn’t hear all of the testimony that each of you gave, 

but I’ve read through, and I would just like to ask you, What do 

each of you think about the widest differences of view for those 

who don’t see any real alarm out there, as opposed to those who 

are—who feel that this is a matter of great urgency? Are we now 

being forced to take actions, if I may use the expression, before it’s 

too late, in terms of the climate change in—that we’re seeing? 

Dr. MURAWSKI. As I said in my verbal testimony—and I’m sorry 

you weren’t here—these factors of increasing acidification of the 

ocean, sea-level rise, changes in the distribution of animals are all 

sources of concern that we have to have, in terms of the ecosystem 

effects of climate change. 

Senator LAUTENBERG. Serious concern. 

Dr. MURAWSKI. Certainly. 

Senator LAUTENBERG. Urgent. 

Dr. MURAWSKI. The urgency of the issue depends on the issue, 

in terms of where we are. 

Senator LAUTENBERG. Well—— 

Dr. MURAWSKI. We have a number of issues—— 

Senator LAUTENBERG.—because we have a debate, an honest debate among us in the Senate, those who think that, as I said in 

my opening remarks, that we’re going to endanger our economy. 

And I have a comma, and that is, ‘‘if we’re still alive after that.’’ 

And so, you know, the—I’m, kind of, one of those who could be 

called an alarmist. The principal reason for that is, I have ten 

grandchildren. They’re very young. And we love the outdoors in my 

32 

family. And it’s not simply going for a swim or fishing. I have a 

grandchild who has asthma fairly severely, and we have to be very 

careful when he over-exercises or what have you. And now, is the 

world that we’re looking at going to endanger his health even 

more? We see a—substantial rises in the number of juvenile 

asthmatics and other autoimmune diseases that are connected to 

the respiratory well-being. Is that—might we expect a turnaround 

in things and suddenly see the air start to clear up? Or will we be 

looking at face masks along the way? 

Dr. MURAWSKI. Well, obviously we’re concerned about issues like 

oceans and human health. That’s a new, emerging set of sciences 

that we’re trying to understand the ramifications of how changes 

in ocean systems influence the prevalence of disease, the relationship of atmospheric issues to ocean changes, et cetera. And those 

are obviously areas of emerging science and emerging interest, in 

terms of you and others. 

Senator LAUTENBERG. Dr. Armstrong, do you have any comments 

about my question? 

Dr. ARMSTRONG. Yes, sir. And I am—I’m sorry you missed my 

oral—part of my oral testimony—— 

Senator LAUTENBERG. I am, too. 

Dr. ARMSTRONG.—as well. I think the issue that you’re really getting at here, first and foremost, is the disagreement on how much 

of what we’re seeing today—and Senator Stevens said it, we’ve 

heard it in testimony—I don’t think there’s much disagreement 

that there is ecological and physical response to global warming, to 

climate change. There are responses. There always have been responses. The question becomes, What is natural change and response, and what is human-induced change? And I think the question really becomes, Can we distinguish between natural climate 

change or climate variability and that influenced or induced by 

human activity? And that is something that I think we still have 

a fair amount of disagreement of, is, How much of each of those 

components plays into what we see today? But we recognize that 

both have a very large role, and we need more science to really 

help distinguish that. But, beyond that, sir, I’d have to say that, 

as a scientist, it isn’t my job to define urgency or what mitigation 

or what policy needs to occur; rather, provide you with the science 

you need in order to—you and others—to make those decisions. 

Senator LAUTENBERG. Well, if we know that human activity 

causes a significant part of the changing climate that we see, are 

we wise to, instead of trying to balance the scales and see which 

comes from where, to get on with that part that we can deal with 

and accept some of the natural responses that we get? Shouldn’t 

we focus on that part, that we know the reduction of the effects of 

the human production of problems to the climate—wouldn’t it be a 

good idea to get going on those things and—— 

Dr. ARMSTRONG. I agree that in order to mitigate, you need to 

understand what you can mitigate. And science can help provide 

the information you need in order to understand what it is that can 

be mitigated and what are the things that may have to—we may 

need to adapt to. But in terms of what those are, I believe that we 

just need to provide you with the best, most relevant science to 

make those decisions. 

33 

Senator LAUTENBERG. Well, if there’s a fire at home, and you 

know that it’s going to engulf you, and—what you do is, you immediately respond to getting the fire out, and not try to just run 

through the house and find the coolest place. And, you know, when 

I see what I think are the irrefutable results of life as we know it, 

is that when we look at places like Glacier National Park and we 

see that it won’t be too long before there are no more glaciers in 

Glacier National, or if we see Kilimanjaro, if we see places in 

Greenland where shelves of ice are floating away and leaving something different—and then Senator Stevens—there are few who are 

better naturalists than Senator Stevens, but Alaska is a place with 

its abundant beauty, but also there are obviously problems arising. 

And when I see what’s happened—there was a—and I’m not sure 

which of the programs I was watching—the polar bears, and how 

their reductions in weight is endangering their existence, and cubs 

are born less—in smaller numbers than they used to be—commonly 

two or three at a time, now it’s barely one at a time, and the reproduction rate is substantially reduced. When I see things like that, 

it—I must confess you, it scares me. 

Now, am I correct in saying of the hottest years on record, 19 occurred in the 1980s, or later, and three of the warmest years on 

record, average global temperatures, in 1998, 2002, and 2005? Stop 

me if I’m incorrect with any of these. 2005 was the highest annual 

average temperature worldwide since instruments—instrumental 

recordings began, in the late 1800s. To your knowledge, are those 

statements correct? 

Dr. MURAWSKI. I believe they’re accurate. 

Dr. ARMSTRONG. Yes. 

Senator LAUTENBERG. Don’t know? 

Dr. ARMSTRONG. I believe they’re accurate. 

Senator LAUTENBERG. They’re accurate. Did you say you weren’t 

sure—— 

Dr. ARMSTRONG. I said I believe they’re accurate. 

Senator LAUTENBERG. Oh, OK. Well, the—that tells me that 

we’ve got to get going. 

I would ask if any of you have—it’s—Mr. Chairman, you’ve 

picked an interesting subject on the—it’s one that should absorb 

even more attention than we’re giving it—have you—either of you 

been approached by NOAA scientists who are concerned that we’re 

not doing enough to address the threat of global warming? 

Dr. MURAWSKI. I’ll take that issue. Obviously, you know, we have 

5,000 scientists in NOAA, and we give scientific opinions on a lot 

of different issues. And we have a lot of intense debate about these 

issues, in terms of what we’re trying to deal with. Admiral 

Lautenbacher, who runs the agency, has expressed to all the staff 

the importance of having open debate, in terms of these issues of 

policy. Our corporate culture is, trying to make sure that the 

science is available. We have an interest in making sure that our 

science is peer-reviewed. And so, once it’s peer-reviewed, it’s generally available in the public. And, you know, we publish that 

science, and we make it widely available within the climate-change 

science program and elsewhere. And so, that’s our corporate policy, 

in terms of dealing with the science that we produce. 

34 

Senator LAUTENBERG. Dr. Armstrong, have you been approached 

by anybody from the USGS registering alarm at the pace of our response to climate change? 

Dr. ARMSTRONG. In terms of the pace of conducting our research? 

Senator LAUTENBERG. Yes. 

Dr. ARMSTRONG. No, sir, I have not. 

Senator LAUTENBERG. Oh, everybody—that—they think that 

we’re moving at the right pace, investing enough resources in doing 

that, is that—is that your view? 

Dr. ARMSTRONG. I—the scientists who I personally fund and am 

responsible for, I believe—we have not had an open discussion 

about that, but I can say that they feel that they’re adequately 

funded to do the work that they have at hand, yes, sir. 

Senator LAUTENBERG. Dr. Murawski? 

Dr. MURAWSKI. I think we have a fair difference of opinion in our 

agency, as any individual science would have a difference of opinion about their research and the importance of their research. And, 

obviously, we have to balance what we can afford with what Congress gives us to do our work. 

Senator LAUTENBERG. Just one last thing, Mr. Chairman. 

Do we have obvious examples—and you may have had this in 

your testimony—commercially significant fish and shellfish, their 

responses to acidification—are these species at risk as a result of 

the changing acid levels in ocean waters? 

Dr. MURAWSKI. Well, it’s interesting, because we had a similar 

event about 55 million years ago, in terms of the rising acidification—— 

Senator LAUTENBERG. I know I’m old, but I don’t remember that. 

Dr. MURAWSKI. Neither do I. And what we saw was rapid loss 

of species of plankton that are the base of the food chain. And so, 

we’re concerned that as acidification rises, that we will see not only 

issues with various plankton species, which support the food web, 

but also the deep corals, which are potentially at risk, as well. 

Senator LAUTENBERG. Thanks, Mr. Chairman. 

The CHAIRMAN. Could I just—— 

Senator VITTER. Sure. Mr. Chairman? 

The CHAIRMAN. I don’t want to be obtuse, but, Doctor, I had a 

briefing from the BLM that located a site in northern Alaska where 

there is a promontory that they decided was—I’m sure you know 

about it, Dr. Armstrong—a watching place for hunters who used to 

hunt dinosaurs—— 

Dr. ARMSTRONG. Yes. 

The CHAIRMAN.—and such animals. Now, I don’t want to offend 

you, but what if, at that period, someone had gotten alarmed about 

the rate of change and tried to disturb the natural occurrence of 

change? Are we in a similar position? 

Dr. ARMSTRONG. Senator, I think that, as I said, if natural 

change is inevitable, and it’s part of just the Earth’s engine and its 

processes, then we do need to understand what it is that we are 

dealing with. We need to understand, as best we can, what is natural change, versus human-induced change, because if we do try to 

mitigate natural issues, natural change itself, if we do not understand, in totality, the system in which that natural change is occurVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00038 Fmt 6633 Sfmt 6601 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
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ring, there may be unforeseen complications or other problems that 

occur due to the mitigation itself. 

So, my point is not to say that we should not mitigate. My point 

is not to say we shouldn’t adapt. My point is simply that the 

science needs to inform you as to our best understanding today 

what is natural change, what do we believe is—based on the scientific information with the degrees of uncertainty we have today, 

what is the human-influenced part of climate change, so that the 

people that are really the ones responsible for mitigation and policy 

on adaptation can make those decisions in an informed environment. 

The CHAIRMAN. Well, thank you. That’s my hope, that we’ll concentrate not just on the change that’s caused by man, but concentrate on trying to understand how much of it is natural. 

Doctor? 

Dr. MURAWSKI. Yes, I’d like to comment on that. I think we’re 

already starting to see some of our public resource agencies stepping out on this and trying to accommodate, you know, changes in 

the Earth’s climate, in terms of the fishery management, for example. And one good example is, in the Pacific there is a phenomenon 

known as the Pacific decadal oscillation, which is a climatological 

feature that varies the climate between Alaska and the Pacific 

West Coast. The fishery managers there know that this happens 

from time to time, and the productivity of the stocks goes up and 

down when these cycles change. And so, what they’re trying to do 

is put in polices that recognize when these cycles are changing 

back and forth, and shift the management accordingly, so that you 

don’t over-harvest in times when it’s poor, or you take advantage 

of, when the cycle is actually favorable. 

The CHAIRMAN. Absolutely. That’s what my interest is. 

Thank you very much. 

Senator VITTER. Just final wrap-up questions. 

Dr. Armstrong, I’m really very interested in your figure 1 in your 

testimony. And, looking at that, one obvious question that jumps 

out is, What might the lag time be between CO2 rises and CH4

rises and temperature rises? Is the past historical record from Antarctic ice cores or anything else with regard to high temperature 

periods clear enough to tell us, in a pretty narrow number of years, 

which is what we’re experiencing in the 20th century, what that 

lag might be so that, you know, we have some beginning of an understanding of whether the temperature chart is about to spike or 

not? 

Dr. ARMSTRONG. Senator, I will—before I give you my answer, I’d 

like to say that I think several of the people, including Dr. Corell, 

on the second panel, are outstanding scientists who ask that very 

same question, too, and will have some very—a more accurate estimate for you, or a more insightful prediction. 

But what I will say is that there is a significant amount of debate in the scientific literature itself about whether or not the 

next—the current interglacial we’re in now is one that will—is 

similar to the past, in terms of frequency and in terms of duration. 

There’s a fair amount of debate over that. There are some scientists who have published recently—in the past 15 years, that 

have said that, based on predictions of orbital forcings and solar inVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00039 Fmt 6633 Sfmt 6601 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
36 

sulation, that we may be looking at a longer interglacial this time 

than what we’ve seen in the last 400,000 years, and that it is, in 

fact, a unique natural cycle that we’re going into. 

I’m not enough of an expert on that field to give you an opinion 

on that, but I would say that that, in itself, is something that we 

need to look into more specifically, as to nail down just what will 

the next 15- to 35,000 years look like in terms of the natural climate change, and how will, with increasing greenhouse gases that 

I think we all agree we’re seeing in the instrumental record—how 

will those impact temperature along with the natural cycle over the 

next 100,000 or tens of thousands of years? 

Senator VITTER. What about the very narrow question I posed 

about the lag time, if any, between CO2, CH4, and temperature? Is 

the historical record, you know, going back a long time to previous 

high temperature eras, precise enough for us to know anything 

about that? 

Dr. ARMSTRONG. I would say that it almost becomes a moot 

point, sir, because of the additive effect of the human-influenced 

greenhouse gas emissions, that we need to have a better understanding of what the response will be to the combined—the additive and the cumulative—effect of natural and human-induced 

greenhouse gases. And I will defer to Dr. Corell on that question. 

I think you’ll get an accurate—a better understanding of the answer to that question. I do not have estimates for you. 

Senator VITTER. OK. Well, what I’m getting at, I don’t think is 

a moot point, because it basically goes to whether, at the end of 

your figure 1, we’re going to experience a spike in temperature or 

not. 

Dr. ARMSTRONG. I do not have the answer to that question. 

That—I didn’t mean to infer that that—you know, your question 

was a moot—— 

Senator VITTER. Right. 

Dr. ARMSTRONG.—point. It’s not. It’s a very important point. And 

it really need—we need to have a better understanding from the 

people that are conducting the models and forecasting forward, 

what will be the additive effect in this case, in this interglacial—— 

Senator VITTER. Right. 

Dr. ARMSTRONG.—which is unique because of the human activity 

on this planet. What will be the additive effect to both greenhouse 

gas emissions for the future, and, therefore, the impact on temperature—global temperatures, for the near future and the long-term 

future? I do not have the answer to that question, sir. 

Senator VITTER. Thanks. And I’d invite, ahead of time, the second panel to respond to that question, too. 

And, Dr. Murawski, in the Magnuson-Stevens reauthorization, 

I’ve included some authority for restoration work for fish habitat, 

particularly with the hurricanes and other events in mind, that 

would go through the National Marine Fisheries Service, through 

NOAA. Do you have any comment about the usefulness of that sort 

of work? 

Dr. MURAWSKI. Well, as you know, NOAA is involved in a number of activities for restoration. There is quite a vigorous program 

in Louisiana, in particular, that’s—the Army Corps of Engineers, 

NOAA, USGS, and the State of Louisiana are involved in someVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00040 Fmt 6633 Sfmt 6601 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
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thing called CWPPRA. And CWPPRA is quite successful. This is 

the Breaux bill. It funds about $55 million a year, in terms of habitat restoration. And the projects that we’re responsible for in 

CWPPRA, have been quite successful. In fact, they negotiated the 

hurricanes quite well, in terms of the design of their properties. 

And we see that coastal restoration can work in those areas, that 

we can mitigate against sea-level loss and loss of those marshes by 

projects that go through that sort of process, where we get the best 

projects, and the highest priority ones. 

Senator VITTER. Great. Thank you all very, very much. Appreciate your testimony. 

Dr. MURAWSKI. Thank you. 

Dr. ARMSTRONG. Thank you. 

Senator VITTER. I was going to, but, Senator, if you have any further questions—— 

Senator LAUTENBERG. Well, just—at what point is there a predictability, that’s reasonable from evidence that you’ve seen in your 

studies, that says that there is no going back to the conditions that 

we’ve seen before—talking about the shellfish, talking about what’s 

happening with wetlands as the flooding takes place and so forth, 

what happens to those bird populations or the fish populations that 

dwell in those areas. Is it expected that there’s always going to be 

some replacement for those? I mean, are we—if we’re going to be 

a hot world, is it likely that we’re going to be able to sustain life 

as we know it? I mean, one thing we know is that there’s going to 

be more carbon poured into our atmosphere than there is now. 

That’s—one doesn’t have to be a forecaster for that. Well, what’s 

that going to do to us? 

And I admire your patience, I must tell you, as you search the 

scientific routes for knowledge. But I’m an ordinary plain human 

being, and I worry about the things that I see in front of me, about 

things that change, temperatures changing, the—I mentioned the 

polar bears. There are other species that are under assault as a result of this. We see penguin populations. I’ve told you spent time 

in Antarctica, and went to the South Pole, and scientists who are 

working there are very worried about what’s happening. 

And, at some point, when do we extinguish the fire before it totally consumes the forest? And at what point do we work on these 

problems that we see in front of us to say there’s enough out there 

to alarm us, to—for us to say, ‘‘Hey, we’re going to find out more 

about the natural cycles that can be anticipated?’’ But we know 

something that we’re doing that has affected it. There’s a report by 

the National Academy of Sciences that say that the human influence on us is a—the changes observed—temperature is, in fact, rising. It’s—the changes observed over the last several decades are 

likely mostly due to human activities. We can’t rule out that some 

significant part of these changes are also a reflection of the natural 

variability—National Academy of Science, 2001. Do we dismiss that 

in the interest of research and say, ‘‘OK, that’s there, but we’ve got 

to get on with it, with doing more research before we dampen the 

fire? ’’ 

Dr. MURAWSKI. Sir, I think most of the research that we’re trying 

to do is to try to frame these sets of issues for people, as yourself, 

the people who make public policy, in terms of how we’re going to 

38 

make adjustments or mitigation or adaptation to these issues. And 

we’re trying to narrow the bounds of uncertainty, and to try to understand particularly the regional effects, which will play out in 

many of the examples that you talked about. 

As to what we do about them, it’s a much larger problem than 

scientists can actually deliver the information and the bounds of 

certainty, but this is in the public-policy arena. 

Dr. ARMSTRONG. Sir, one of our—— 

Senator LAUTENBERG. Doctor? 

Dr. ARMSTRONG.—responsibilities is—at USGS is—being the 

science wing of the Department of the Interior, is to provide science 

information to our land resource brethren at National Park Service, 

Bureau of Land Management, Fish and Wildlife Service, Bureau of 

Indian Affairs. And I will tell you that the problems that you’ve addressed today are real problems, and they are things that we are— 

the response of polar bears, of seals, of invasive species, of plants 

and other animals, especially in climate-sensitive areas, are things 

that we are currently addressing and looking into and trying to develop an understanding of the cause and effect. What causes a 

polar bear to lose weight, or what causes a seal population to migrate to other areas? We’re looking at these things now. 

And I would actually say to you that it would be irresponsible 

of us, as scientists, not to provide you the information you need 

and to give you our best professional judgment. But, in doing that, 

we need to show you, also, what degree of certainty and what kind 

of confidence level can we give you that information you need to 

make decisions with. And that’s the thing that we’re working on 

now, is trying to better understand those cause-and-effect processes. 

Senator VITTER. Second panel. 

Senator LAUTENBERG. Yes, OK. So—and I’ll wrap up here—I 

just—would it be advisable for us to try to reduce deforestation of 

our wooded lands? Do they matter? Would it be wise for you folks 

to say, ‘‘Hey, listen, cut down on the amount of carbons that are 

released into the atmosphere’’? We’re—is that a good idea, or is 

that to be left for another day or another year, another century? 

Dr. ARMSTRONG. I think it’s appropriate for the policymakers and 

the resource managers to give you that information that they determine to be appropriate. At USGS, it’s up to us to provide the 

science to those people that make those decisions. 

Senator LAUTENBERG. Thank you. 

Senator VITTER. Thank you all very much. 

Dr. ARMSTRONG. Thank you. 

Senator VITTER. And as the second panel is taking the witness 

table, I’ll begin to introduce our three panelists who comprise the 

second panel. 

First we’ll hear from Dr. Syun–Ichi Akasofu, Director of the 

International Arctic Research Center in Fairbanks, Alaska. And we 

thank him, again, for traveling such a distance to be with us. We’re 

also joined by Dr. Robert Corell, Senior Policy Fellow of the American Meteorological Society and affiliate of the Washington Advisory Group; and, also, Dr. Paul Reiter, Professor of the Institut 

Pasteur, in Paris, France. And we also thank him for traveling 

such a long distance. 

39 

And as soon as everyone is settled, we’ll begin with Dr. Akasofu’s 

testimony. 

Thank you. 

The CHAIRMAN. Could I introduce Dr. Akasofu to you? 

Senator VITTER. Absolutely, Mr. Chairman. 

The CHAIRMAN. I just think you should know that Dr. Akasofu 

conceived the idea of the Arctic Research Center and obtained the 

support of Japan and of Canada and the United States, and, to a 

certain extent, of Russia, for the activities that are conducted 

there. This is an international center. Substantial Japanese funds 

have gone into that, as well as others. And I think we owe him a 

debt of gratitude for what he’s done, dedicated a substantial portion of his life to this one area of science. 

Senator VITTER. Absolutely. I agree completely. 

Doctor? 

STATEMENT OF DR. SYUN–ICHI AKASOFU, DIRECTOR, 

INTERNATIONAL ARCTIC RESEARCH CENTER, UNIVERSITY 

OF ALASKA FAIRBANKS 

Dr. AKASOFU. Mr. Chairman and members of the Subcommittee, 

I really appreciate, thank you for providing me with the opportunity to testify at this important hearing today. 

The CHAIRMAN. Syun, pull the mike toward you, will you? Pull 

it right—— 

Dr. AKASOFU. Let’s see. As Senator Stevens says, that I am the 

Director of the International Arctic Research Center. Senator Stevens helped us to establish the center. We have been working on— 

specifically on climate change. 

I would like to summarize my testimony. And the most—the 

prominent warming in the world was taking place in the continental Arctic during the last half of the last century. So, it—the 

three times more than the rest of the world. So, the warming signals are the largest, so we like to concentrate on that to try to understand it. 

The—in the continental Arctic, we have—because of warming, we 

have degradation of permafrost—forests and so on, and many other 

phenomena. 

However, we have at least two firm scientific indicators that 

show it is incorrect to conclude that this warming in the continental Arctic is due entirely to the greenhouse effect caused by 

man. The first indicator is that most advanced 14 IPCC global climate models, which includes the best scientific knowledge of the 

greenhouse effect, cannot reproduce the warming of the continental 

Arctic during last half of the last century. The IPCC cannot reproduce. This is what we call hindcasting. We are using last 50 years 

of data, last IPCC—best IPCC group to reproduce that. And so, we 

think it’s best scientific test of the greenhouse hypothesis. 

In the scientific methodology, what we do is we make observation—in this case, global warming. Then we hypothesize the causes 

of the warming, the second step. And the last step is to verify the 

hypothesis. If necessary, using the supercomputer. And if computer 

simulation and observation agree, then the observations and the— 

our understanding becomes scientific fact. 

40 

But if there is—computer cannot reproduce what we observe, 

then the hypothesis has to be disproved. And—but you still insist 

that—someone still insists that greenhouse effects is going, then 

that belongs to the area of what we call science fiction, because the 

science fiction you don’t have to rely on any science. 

So, then—so, the first test is, we cannot reproduce the continental warming, which is—as the largest, most prominent feature 

of the warming today. The second indicator is that geographic pattern of the warming in the Arctic has been drastically changing 

during the last—in recent years. Strong continental Arctic warming 

trend is no longer evident during the last two decades. 

If the warming trend during the last half of the last century were 

entirely due to the greenhouse effect, the past geographic pattern 

of the warming should intensify, but this is not the case. Various 

warming and cooling of similar magnitudes has continuously occurred at different locations and different times during the last 

hundred years. So, it’s natural to conclude that such a trend will 

continue, as Dr. Armstrong said, the—both natural and manmade 

component. 

In addition, long-term record of the glaciers and the sea ice show 

that they have been—those glaciers and the sea ice have been receding around about 1,800, well before the CO2 effects became serious. We have some evidence that the present recession of sea ice 

in the Arctic Ocean is due partly to the intrusion of warm North 

Atlantic water, which is caused by what we call North Atlantic oscillation, a natural phenomenon, like El Nin ̃ o. So, this warm water 

is now flowing around the Siberian coast and approaching Alaska. 

Also, it’s very important to notice that our sun is changing. The 

solar physicists have been working on this for years, and they’ve 

found that very important solar output is changing. 

So, it is my conclusion that it is urgent to identify both natural 

and manmade components of the present warming. So, results that 

will be—of—like house-fire example that Senator mentioned, we 

are not sure if the house is really on fire. And to put the water 

where it would make water damage may be more damaging. 

That’s my testimony. 

[The prepared statement of Dr. Akasofu follows:] 

PREPARED STATEMENT OF DR. SYUN-ICHI AKASOFU, DIRECTOR, INTERNATIONAL

ARCTIC RESEARCH CENTER, UNIVERSITY OF ALASKA FAIRBANKS

Thank you for providing me with the opportunity to testify at this important hearing today. 

In order to avoid any misunderstanding, I would like to state at the outset that 

it is in the best interests of mankind to reduce the rate of increase of our release 

of CO2. My talk is about how much this future reduction should be. For this purpose, I would like to demonstrate that: 

1. Prominent climate change is in progress in the Arctic, compared with the rest 

of the world. However, 

2. arctic climate change consists of both natural change and the greenhouse effect, and thus 

3. it is incorrect to conclude that the present warming in the Arctic is due entirely to the greenhouse effect caused by man. 

4. Therefore, it is important to find out the contribution of both natural and 

manmade components to the present climate change in the Arctic. 

The first statement can be illustrated in Figure 1. The range of temperature 

change along the coastline of the Arctic Ocean is much greater than that of the globVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00044 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
41 

al average. Please note a rapid increase from 1920 to 1940, a decrease from 1940 

to 1970, and a rapid increase again from 1970 on. 

It is also important to note that both the Arctic and global temperatures began 

to decrease in about 1940, when our release of greenhouse gases began to increase 

rapidly. Thus, the increase-decrease between 1920 and 1970 must be natural 

change. One important task we have is to find out the nature of the warming periods from 1920 to 1940, and from 1970 to the present time. An important question 

is whether or not the present rise will continue or whether future temperatures will 

decrease, as was the case during 1940 to 1970. 

Let us examine where in the Arctic temperature changes occurred during the last 

half of the last century. The left-hand side of Figure 2 shows clearly that the most 

prominent warming was in the continental Arctic (Siberia, Alaska, and Canada), except in Greenland, where it cooled. 


aka1.eps
42 

The IPCC Arctic Group, consisting of 14 Global Climate Modeling (GCM) teams 

headed by V. Kattsov, tried to reproduce the temperature change for about the same 

time period on their models. Their results are shown in the right-hand side of Figure 2. The simulation result bears no resemblance to the observed, real temperatures in the continental Arctic. If the simulation were reasonably accurate, the results should be similar. This is the most quantitative test to date to examine if the 

continental arctic warming during the last half of the last century was caused by 

the manmade greenhouse effect. This comparison shows clearly that much of the 

prominent warming in the continental Arctic after 1970 was not caused by the 

human-induced greenhouse effect. 

If, in fact, the continental warming indicated in the right-hand side of Figure 2 

were caused by the greenhouse effect, this trend should have been intensified during 

the last few decades. However, that is not the case. The continental warming in the 

upper part of Figure 3 (which is similar to the left-hand side of Figure 2) is absent 

during the last 20 years (the lower part of Figure 3). Thus, the continuous increase 

of the warming is not taking place any more. Instead, intense warming is now in 

progress in Greenland, which experienced cooling in the recent past. 


aka2.eps
43 

Further, let us examine temperature changes during the last century. Figure 4 

is similar to Figure 1, except it includes the Subarctic, and the zero line represents 

the average value of the last century. One can see that warming and cooling continuously occurred during the last century. Thus, it is not difficult to infer that the 

rise after 1970 is not entirely due to the manmade greenhouse effect. 


aka3.eps
44 

Fortunately, we now have longer-period ice core data from an island in the Arctic 

Ocean. It is shown at the top of Figure 5. The bottom trace is the reproduction of 

Figure 1, and the middle one is the temperature record in northern Norway. All 

three traces show similar change from 1900. In addition, the ice core data show 

clearly that there are both linear and irregular changes from 1725, well before the 

effects of the Industrial Revolution became serious. Thus, it is clear that the last 

rise since 1970 is not entirely due to the greenhouse effect. 


aka4.eps aka5.eps
45 

It is likely that part of the rises and falls of temperature in 1920–1970 can be 

identified as what is called a ‘‘multi-decadal change.’’ One possible cause of this 

multi-decadal change is the changing intensity of the intruding warm North Atlantic water into the Arctic Ocean (Figure 6), which is associated with a natural phenomenon called the North Atlantic Oscillation (NAO). At the present, the warm 

water is flowing toward the Alaska coast. Studying and tracking this warm-water 

pulse, which may be a natural reason for some loss of sea ice, is one of the major 

projects of the International Arctic Research Center (IARC), conducted with the help 

of the Russian Icebreaker Kapitan Dranitsyn. 

In recent years, there have been a large number of reports that both glaciers and 

sea ice in the Arctic Ocean have been receding. However, longer-term records show 

that such phenomena have been in progress continuously since 1800 or earlier (Figures 7a and 7b), and are not phenomena that began after 1970. Glaciers in the Glacier Bay National Park began to recede at least by the time Captain Vancouver 

passed by in 1794, and the ice edge in the Norwegian Sea began to recede in about 

1800. 

These data show clearly that it is dangerous to infer causes of climate change 

using only data that cover the last 40 years or so. In recent years, there have been 

a large number of excellent papers that describe arctic climate change since about 

1970. This is because high quality satellite data became available only after 1970. 

Fortuitously, this period also coincides with the beginning of temperature rise durVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00049 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE

aka6.eps aka7.eps
46 

ing the last several decades. Thus, all such reports on scientific results are naturally 

related to the topic of rising temperatures. 

Although I respect the authors of those papers, I cringe somewhat when the papers are consumed immediately by the media and then the public. Unfortunately, 

members of the press often champion these papers as showing examples of the 

greenhouse effect, which tends to sensationalize the results. Thus, the general public often interprets the results to mean that all climate change in the Arctic must 

be caused by the manmade greenhouse effect. 

These scientific reports should be treated like any other scientific papers in professional journals. Any significant conclusions should be scrutinized by the scientific 

community before they become material for public consumption. This requires a certain period of time. Although I am happy to have the present great public interest 

in our research topic of global warming, such instant reporting of results for relatively short time periods can cause much confusion in the minds of the public. It 

is not as simple as stating that ‘‘warming melts ice.’’ 

Unfortunately, data gathering for periods before the 1970s is much more difficult 

and much more time consuming than obtaining satellite data. Today, many climatologists tend to avoid dealing with the topic of climate change before the 1970s. 

Further, those data may not be of the quality researchers desire, and some researchers tend to discredit results based on data before 1970, which is a good excuse to 

avoid longer-period data. Therefore, these days there are only a handful of researchers who deal with climate changes over the last century in great detail. In fact, it 

is alarming that only a few researchers in the world are studying the sharp increase 

of temperature that occurred from about 1920 to 1940 and the sharp decrease that 

occurred from 1940 to 1970. 

Our understanding of the change between 1920 and 1970 is crucial for interpreting the rapid rise from 1970 on and also for future predictions, because the 

change between 1920 and 1940 is most likely a natural one. If computer modeling 

were adjusted to reproduce the present rise, assuming that the present rise is due 

entirely to the greenhouse effect, its prediction for future years will not be accurate. 

We tend to forget that some climatologists, who were studying the temperature 

decrease from 1940 to 1970, warned the public that a new Ice Age was just around 

the corner. Apparently, we have not learned the lesson of the ‘‘new Ice Age mistake’’: short-period data do not tell the whole story. 

In conclusion, the nature of the climate change after 1970 should be a matter of 

great debate. It should not be assumed that this short period of warming is entirely 

due to the greenhouse effect caused by the actions of man. The prediction of future 

trends depends greatly on the understanding of the nature of the rise after 1970. 

Thank you again for the opportunity to present this testimony today, and thank 

you for your interest in this important issue. Please feel free to contact me if you 

have any additional questions. 

References 

ACIA (Arctic Climate Impact Assessment), Cambridge University Press, 2005. 

Fritzsche, D., R. Schutte, H. Meyer, H. Miller, and F. Wilhelms, T. Opel, L.M. 

Savatyugin, Late Holocene ice core record from Akademii Nauk Ice cap, 

Severnaya Zemlya, Russian Arctic, in Papers accepted for publication in Annals 42, International Symposium on Arctic Glaciology, Geilo, Norway, 23027 

August 2006, J.W. Dowdeswell and I.C. Willis, Eds., Annals of Glaciology, No. 

42, A150, 2006. 

Hansen, J., L. Nazarenko, Reto Ruedy, Makiko Sato, Josh Willis, Anthony Del 

Genio, Dorothy Koch, Andrew Lacis, Ken Lo, Surabi Menon, Tica Novakov, 

Judith Perlwitz, Gary Russell, Gavin A. Schmidt, and Nicholas Tausnev, 

Earth’s energy imbalance: Confirmation and implications, Science, Vol. 308, 

no. 5727, pp. 1431–1435, doi:10.1126/science.1110252, 2005. 

IPCC (Intergovernmental Panel on Climate Change), http://www.ipcc.ch. 

Polyakov, I., R.V. Bekryaev, G.V. Alekseev, U. Bhatt, R. Colony, M.A. Johnson, and 

A.P. Makshtas, Variability and trends of air temperature and pressure in the 

maritime Arctic, 1875–2000, J. Climate, 16(12), 2067–2077, 2003. 

Polyakov, I.V., G.V. Alekseev, L.A. Timokhov, U. Bhatt, R.L. Colony, H.L. Simmons, 

D. Walsh, J.E. Walsh, and V.F. Zakharov, Variability of the intermediate Atlantic Water of the Arctic Ocean, over the last 100 years, J. Climate, 17(23), 

4485–4497, 2004. 

Vinje, T. Anomalies and Trends of Sea-Ice Extent and Atmospheric Circulation in 

the Nordic Seas during the Period 1864–1998, J. Climate, 14, 255–267, 2001. 

Wiley, S.D., Blue Ice in Motion: the story of Alaska’s Glaciers, The Alaska Natural 

History Association, 1990. 

47 

Senator VITTER. Thank you very much, Doctor. 

Dr. Corell, welcome. 

STATEMENT OF DR. ROBERT W. CORELL, 

SENIOR FELLOW, AMERICAN METEOROLOGICAL SOCIETY; 

AFFILIATE, WASHINGTON ADVISORY GROUP; 

CHAIR, ARCTIC CLIMATE IMPACT ASSESSMENT 

Dr. CORELL. Thank you, and good afternoon, Mr. Chairman, Senator Stevens, Senator Lautenberg, and all gathered here. I really 

appreciate the opportunity to join you in this hearing today. 

I’d like to put some context for our discussion, because there 

have been significant shifts of the climate in our planet, with substantial changes and increases in temperature, particularly during 

the last 150 years or so, as reported by Professor Moberg and many 

others who have documented, as depicted here, the picture over the 

last 2,000 years, the so-called hockey stick. And, as you can see, 

the instrumental record is clear that things are happening in the 

last 150 years that certainly are unparalleled in the last 2,000 

years. 

The IPCC third report concludes that while some of the fluctuations we see—and you can see them here, they are natural in character—come from natural variability, it is clear now, to the IPCC 

any ways, that human influences are responsible for most of the 

roughly 1 degree Fahrenheit global warming that has occurred over 

the 20th century, and that the IPCC predicts and suggests that 

those temperatures, over the next hundred years, may reach as 

much as 5 to 9 degrees Fahrenheit. 

First let me say a word or two about the ocean and the marine 

setting. A simple and important message, the oceans control the 

timing and magnitude of the changes of the climate system, and do 

so over decadal timescales. Further, the—any imbalance of incoming radiation—and we do have an imbalance at the moment—90 

percent of that energy ends up in the ocean. The 10 percent is what 

we hear about, reducing sea ice, melting glaciers, warming the atmosphere. So, the oceans are the dominant player in the situation. 

Professor and Dr. Hansen and his group in Columbia have done 

an extensive study of the last 10 years of this increased warming 

of the ocean, and have concluded that the Earth is now absorbing 

about .85, plus or minus a small amount, watts per square meter. 

That number doesn’t mean anything, but it does mean the following, and that is, already stored in the ocean is another .6 degrees, or roughly 1 degree Fahrenheit, of warming of the planet 

without any further increase of greenhouse gases in the atmosphere. So, it’s like a supertanker. It stores it, and it takes a long 

time for it to play out. 

And, in that regard, Mr. Chairman, in answer to your question, 

at least when we’re combining warming that’s due to both natural 

and anthropogenic factors, it’s clear that there is a lead-lag relationship, that, as CO2 goes up and the warming takes place of the 

ocean, it will take a somewhat longer time for that to be expressed 

as a warming of the overall atmosphere. 

This oceanic warming has a wide range of impacts, both physically and biologically. The first is that there’s a long-term effect on 

sea level, which I’ll come back to. As the heat is propagated downVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00051 Fmt 6633 Sfmt 6601 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
48 

ward into the ocean, we’re only heating the upper few hundred meters already, and we have 4,000 meters to go. And as that heat 

propagates down, the oceans expand, and sea level will continue to 

rise. And I should note that most of the sea-level rise that we’ve 

experienced to date has come from this thermal expansion of the 

ocean, and not from land-based ice melting. 

As Dr. Murawski has indicated, there certainly is a clear impact 

on fisheries, marine mammals, sea birds, and other marine life, 

and it will have a significant change in the future. The shift in 

fisheries have already been observed, and will continue to occur as 

both oceanic temperatures and currents shift. Marine mammals, 

including walrus, sea whale, seals, and polar bears, are already 

being impacted, as Senator Lautenberg aptly pointed out. 

While the ocean, as a whole, can store vast amounts of CO2, it’s 

not very well mixed, and much of that absorption of CO2 builds up 

near the surface. And this has the effect of altering the oceanic 

chemistry and resulting in increased acidity of the ocean, which 

has already been noted by previous testimony. 

What I’d like to note here is that as the CO2 in the atmosphere 

increases from our present level, about 380 or so parts per million, 

up toward the 6–700 region, laboratory experiments on the calcification process of plankton strongly indicate that these animals—or 

these plants at the lower end of the food chain will have a very difficult time forming. And you can see the difference between the 

lower left and the lower right. So, the acidification will play a profound role, and the impact in the whole life chain in the oceanic 

region. 

The extent of summer sea ice has already been reduced by about 

20 percent in the past 20 years or so, and the Northern Sea route 

is already opening up along the Russian coast, which will, in the 

end, open up seaways that are about 45 percent closer in time between the two markets of the Far East and Europe. 

What are some of the impacts in the terrestrial biosphere? 

Changes in CO2 itself will have an effect on the terrestrial biosphere. As a result, higher concentrations will lead to greater carbon uptake by plants. Storage in the plant material will increase 

as long as the soils have adequate nutrients, such as nitrogen, to 

support it. Food production will likely increase in the short term, 

or at least until concentration gets sufficiently high that—where 

other factors will start limiting their productivity. 

So, for natural systems in forests and grasslands, the situation 

is likely to be even more problematic than it is in the agricultural 

region. Each ecosystem has a preferred set of conditions, relationships between each element in the system. And as the climate 

shifts some range—some ecosystem elements can move slowly, 

some move fastly. And, therefore, the out-year composition of those 

ecosystems is likely to be quite different than they are now. 

The temperature increases that we’ve already experienced in 

Alaska since 1970 in the Kenai peninsula have indicated how disastrous those modest temperature increases can have, because the 

over-wintering of the spark—the spruce bark beetle has already led 

to sudden and really widespread loss of the white spruce forests. 

Finally, the projected increase in frequency of droughts, wildfires, 

floods, and other extremes, such as hurricanes, are the kind of 

49 

thing that we can expect to have impact not only on our ecosystems, but on our society as a whole. And because these projected 

changes are evident in the frequency of the events, the timing and 

the intensity, and the localization of some of the participation, all 

sorts of challenges lie ahead, some of which we have ability to see, 

others of which will require continued research, and one of the 

most important of which is the status of freshwater reserves 

around the planet. 

Now, in the Arctic, the melting of snow cover and the river-ice 

permafrost combined with the loss of sea ice has had, and will continue to have, a really profound effect on wildlife, particularly on 

its movement across the regions. Warmer species—warming conditions have already resulted in new species. If you go to the Inuits, 

in the north of Canada, the word ‘‘robin’’ doesn’t exist in their vocabulary or in their language, and robins are now prolific in those 

regions. 

As a result of these kinds of changes across the U.S. and also 

around the world, conditions such as heat waves, drought conditions, will be more favorable to propagate wildfires, as Alaska has 

experienced one of the most incredible wildfires a couple of years 

ago, of 600—6.5 million acres destroyed in one setting. 

On the other side of the precipitation question, there is going to 

be more intense—— 

Senator VITTER. Doctor, if you could start to sum up, I want 

to—— 

Dr. CORELL. I would—surely. There will be more intense rainfall, 

which will result in more flooding. 

I want to say a word or two about Greenland. The ice melting 

there is pretty dramatic, as you can see in these images. And there 

has been a melt of about 20 percent increase just in the past 25 

years, and last year the melt region was the largest in recorded 

history. 

Sea-level rise will have an impact, such as 1 meter of sea-level 

rise on Florida, as indicated in this diagram here; and elsewhere 

around the planet, even more profound implications. 

I was just recently in Alaska to visit Shishmaref, which is a very 

important village to the Alaskans, and the picture in the lower 

right—lower left-hand corner was taken only a couple of weeks ago. 

It resulted from a storm last fall, that the sea ice used to protect 

that shoreline, and the sea ice is no longer there to do so. And, as 

a consequence, the village is going to have to move, at very costly 

levels. 

So, the Arctic now is really experiencing some of the most rapid 

and severe changes, and it’s going to be that way in the future. 

Let me just summarize by saying that the Arctic is one of the 

most important regions to note what’s happening. As Senator Stevens said, it’s the bellwether, it’s the place in which we will see the 

most change most rapidly, and it is a part of our country. 

And while it’s clear to me that global change is here, we’ve got 

a major task ahead of us. I urge all of us to join together in giving 

this serious attention to look at assessments as a vehicle by which 

science can communicate its knowledge at global, regional, and national levels to policymakers like yourself. 

Thank you for your attention and your time. 

50 

[The prepared statement of Dr. Corell follows:] 

PREPARED STATEMENT OF DR. ROBERT W. CORELL,1 SENIOR FELLOW, AMERICAN

METEOROLOGICAL SOCIETY; AFFILIATE, WASHINGTON ADVISORY GROUP; CHAIR, 

ARCTIC CLIMATE IMPACT ASSESSMENT

Introduction 

Mr. Chairman, Members of the Subcommittee, and all gathered here today, I 

thank you for the opportunity to participate in today’s hearing on the ‘‘Projected and 

Past Effects of Climate Change: A Focus on Marine and Terrestrial Systems.’’ I am 

honored to join you to explain the science that underpins understanding of the past 

and projected effects of climate change, especially in terms of the impacts on marine 

and terrestrial systems in North America, across the Arctic region, and around the 

world. 

In offering these perspectives, I will be drawing primarily from the findings of 

major scientific assessments, a number of which I have been involved with, because 

these assessments very thoughtfully draw together the collective findings of the scientific community. These assessments deserve very high and special consideration 

because their credibility has been well established as a result of their extensive open 

review processes, which have helped to carefully hone their findings. 

At the national level, I will be drawing upon the results of the U.S. National Assessment that was completed 5 years ago.2 In my role from 1990–1999 as chair of 

the Subcommittee on Global Change Research that directed the U.S. Global Change 

Research Program, I was instrumental in the organization of this assessment, and 

after I left government service I served on the National Assessment Synthesis Team 

that summarized the assessment’s findings. In describing potential consequences for 

the Arctic, I will be drawing mainly from the results of the Arctic Climate Impact 

Assessment (ACIA), which was completed in 2004,3 having been established and 

charged to conduct the assessment by the Arctic Council 4 and the International Arctic Sciences Committee.5 For ACIA, I served as chair, leading an international team 

of over 300 scientists, other experts, and elders and other insightful indigenous residents of the Arctic region in preparing a comprehensive analysis of the impacts and 

consequences of climate variability and changes across the Arctic region. At the 

international level, I will be drawing mainly from the results of the Intergovernmental Panel on Climate Change (IPCC), which I was instrumental in helping to 

conceive in the late 1980s in my role as Assistant Director for Geosciences at the 

National Science Foundation (NSF) from 1987–1999. The IPCC’s members are the 

nations of the world and the periodic assessments that they commission represent 

the collective evaluation of scientific understanding by the international scientific 

community. That the IPCC’s assessments of 1990, 1995, and 2001 have been unanimously accepted by the world’s community of nations gives a strong indication of 

the widespread agreement that exists regarding the major finding that human-induced climate change is already influencing the climate and the environment and 

that much larger changes lie ahead.6 For more detailed information and scientific 

citations on most of my points, reference should be made to the cited assessments. 

In areas where the pace of research has been especially rapid or significant in recent years, however, I will also be drawing upon the results of more recent scientific 

articles, which I will specifically reference. 

Context for Today’s Hearing 

The IPCC’s Third Assessment Report 7 summarized the peer-reviewed scientific 

evidence that human activities, in particular the ongoing emissions of carbon dioxide (CO2) and other greenhouse gases to the atmosphere resulting primarily from 

the combustion of coal, oil, and natural gas, are causing the Earth’s climate to warm 

more rapidly and persistently than at any time since the beginning of civilization. 

While some of the fluctuations are likely a result of natural factors (e.g., variations 

in solar irradiance and major volcanic eruptions), the IPCC evaluation concluded 

that the strength and patterns of these change makes clear that human influences 

are responsible for most of the roughly 0.6°C (1°F) warming during the 20th century. In particular, despite the cooling influence of the 20th century’s largest volcanic eruption in 1991, the fifteen warmest years in the instrumental temperature 

record available since 1860 have all occurred in the last 25 years,8 and comparison 

with paleoclimatic reconstructions 9 of temperatures over the last two thousand 

years indicates that recent warmth is unprecedented, at least for the Northern 

Hemisphere where paleoclimatic data are most available.10 In addition to the warming of the surface, which has been particularly strong in the Arctic,11 warming is 

also evident in ocean temperatures (causing some of the sea level rise), below 

51 

ground temperatures, and temperatures well up in the troposphere.12 Other evidence of climate change includes diminishing sea ice and snow cover in the Northern Hemisphere, melting back of mountain glaciers in the tropics and in most other 

locations around the world, and an increasing tendency for precipitation to occur in 

relatively heavy amounts. 

For the future, IPCC projects that significantly greater warming lies ahead. Considering a wide range of possible scenarios for how human activities (e.g., changes 

in population, technological development, energy use and supply, economic development, and international cooperation) are likely to alter atmospheric composition 

during the 21st century, the IPCC projects a further increase in average annual surface air temperature around the globe of roughly 1–2°C (1.8–3.6°F) from 1990 to 

2050 and a further 1–2.5°C (1.8–4.5°F) by 2100, bringing the projection for total 

human influence from the start of the Industrial Revolution to 2100 to roughly 2.5– 

5°C (about 4.5–9°F).13 As is the case for the warming over the 20th century, future 

changes are expected to be greater over land than over the ocean, greater in midto high latitudes than in low latitudes, and, except where regions really dry out, 

greater during the winter than during the summer and greater during nighttime 

than daytime. As will be explained more fully in discussing likely impacts, many 

other aspects of the world’s weather and climate will also be affected. 

That such changes in the climate will occur as a result of human activities is no 

longer scientifically controversial. During the rest of my testimony, I will discuss 

what the likely consequences of the changes in atmospheric composition and climate 

are likely to be for the environment, focusing on three specific domains: 

• Oceans and marine systems; 

• The terrestrial biosphere; and 

• The interface between the marine and terrestrial environments. 

My discussion will focus on the links between climate change and these systems. 

It is important to recognize, however, that a number of additional stresses are affecting each of these environments, including air pollution, nitrogen deposition, 

toxics such as mercury, unsustainable extraction of resources, over-fishing, nutrientinduced eutrophication, depletion of stratospheric ozone and UV enhancement, etc. 

Climate change is thus only one aspect of global environmental change, although 

a continuously accumulating one that over time will have very large impacts, and 

for a full evaluation of likely environmental consequences for both marine and terrestrial environments, comprehensive research and assessment efforts are essential. 

Interactions and Impacts Linking Climate Change and the Ocean and 

Marine Environment 

Oceans cover about 70 percent of the Earth’s surface. Because of their large heat 

capacity, the oceans moderate climatic swings by supplying heat to the atmosphere 

and adjacent continents during the winter and, because they warm relatively slowly 

during the summer, are the source of cooling sea breezes during times of peak solar 

radiation. Much of the heat absorbed by the oceans goes into evaporating water, 

providing the moisture that supplies vital precipitation for land areas via the monsoons and tropical and extratropical storms. These rains and associated geochemical 

interactions help to cleanse the atmosphere of pollution. In addition, oceans support 

a wide diversity of biological life that supplies fish, birds, marine mammals and 

other species higher in the food chain, and supports the fisheries that in turn provide substantial food for humans. 

While the oceans seem so large that it is hard to imagine that human activities 

could affect them, records over geological time and observations of recent changes 

make clear that both the physical and biological systems in the ocean are quite sensitive to changes, and, indeed, are being affected. The very human activities that 

are causing the climate to change are becoming the major influence on the oceans. 

First, the oceans affect atmospheric chemistry. In their natural state, cold waters 

forced to the surface by wind patterns in low latitudes release large amounts of CO2

to the atmosphere as they warm. Before humans started altering the carbon cycle, 

roughly the same amount was taken up in mid- to high latitude ocean areas as the 

ocean waters cooled and marine organisms grew, died and sank to the ocean depths. 

With this balance, which was modified somewhat during glacial periods when the 

oceans were colder, the atmospheric CO2 concentration has been held in the range 

of about 180 to 300 ppmv 14 for the past several million years. As human activities 

began to emit large amounts of CO2 as a result of combustion of coal, oil, and natural gas, the atmospheric concentration has been driven higher because the oceans 

and living biosphere cannot absorb it all. On time scales of years to centuries, the 

oceans take up about a third of the emitted amount, limiting the atmospheric buildup and thus moderating the pace of climate change. 

52 

While the oceans as a whole can hold vast amounts of dissolved CO2, the oceans 

are not well mixed vertically, and so most of the added CO2 builds up in the near 

surface layer. This has the effect of altering oceanic chemistry, most importantly by 

making the ocean more acidic.15 Increasing oceanic acidity has a range of effects, 

but the most important is that it makes it chemically more difficult for marine organisms to form shells. For corals, the rise in the CO2 concentration from its 

preindustrial value of about 280 ppmv to its present value of 380 ppmv has already 

caused a significant shrinkage in the regions most favorable for reef-forming, and 

by 2050, virtually all of the most favorable regions in the world will have disappeared, simply due to the rise in the CO2 concentration.16

Adding in the sensitivity of corals to warmer ocean waters (the ‘‘coral bleaching’’ 

effect), the prospect for more powerful storms and wave conditions, the increasing 

threats from coastal runoff and fish-harvesting, and other stresses, the prospects for 

many of the world’s reefs are very problematic. While the potential impacts on coral 

are of most immediate concern, impacts on other shell-forming organisms are also 

likely to become significant over coming decades, particularly as the CO2 level approaches 750 ppmv.17

As the rising concentrations of CO2 and other greenhouse gases have trapped 

more infrared radiation, making it more difficult for the Earth’s surface to cool, 

most of the additional heat has been taken up by the oceans because they are capable of mixing it through the upper hundred meters (yards) or so of ocean depth. Surveys of ocean temperature give a clear indication that the ocean’s upper layers are 

warming; 18 indeed, the warming that is being observed is in good agreement with 

climate model simulations of how the oceans are being projected to warm as a results of the changes in atmospheric composition.19

This oceanic heating is having a wide range of both physical and biologically important impacts. Because the oceans are able to mix the heat downward, they are 

able to slow the warming of the atmosphere, which is beneficial, but it also means 

that we are not experiencing the full extent of warming to which past emissions of 

CO2 have committed the world. Experiments with climate models indicate, for example, that the world would be committed to further warming of about 0.5°C (almost 

1°F) even if global emissions of CO2 were to be quickly cut to near zero. 

Warming of the oceans also makes more energy available to the atmosphere if just 

the right conditions prevail. For example, warm ocean waters provide the energy 

needed to intensify tropical cyclones (i.e., hurricanes and typhoons), and indeed, recent studies 20 are finding that increasing sea surface temperatures are leading to 

an increasing proportion of tropical cyclones to be in the most powerful and destructive categories (more on the consequences of more powerful tropical cyclones in the 

section dealing with the ocean-land interface). While there has been significant debate recently about whether the available record provides a definitive indication of 

this linkage, a paper in press in the Bulletin of the American Meteorological Society, 

of which I am a co-author, finds that there are many reasons to suggest that there 

is indeed a strong linkage and that it may well be limitations in our detective work 

that are the problem.21 If this is indeed the case, and it seems quite likely, then 

the world faces a situation where the storm season is becoming longer, storms may 

well last longer, and the likelihood of relatively intense storms is increasing, likely 

leading to greater and greater destruction and loss of life unless our adaptive efforts 22 are significantly increased. 

Climate change also has the potential to influence the pattern and character of 

the normal year-to-year fluctuations of the climate. For the Pacific region and then 

for much of the U.S., the natural variation of the El Nin ̃ o-Southern Oscillation 

(ENSO) is of critical importance, variously causing El Nin ̃ o and La Nin ̃ a events (i.e., 

unusual warming or cooling in the eastern tropical Pacific, respectively) that redirect the Northern Hemisphere jet stream, thereby creating either quite wet or quite 

dry winter conditions across various parts of the U.S. (e.g., this year, the ocean conditions are causing the U.S. West Coast to be inundated with very large amounts 

of rain). Research to date only hints at how ENSO may be affected, with some indication that the overall conditions may become more El Nin ̃ o-like with more intense 

El Nin ̃ o events (meaning, for example, more winter precipitation for California, increasing flooding potential in the spring and increasing the stock of burnable vegetation). However, there remains significant disagreement among model results and 

this area is, therefore, being investigated intensively by various research groups. 

Changes in atmospheric winds and weather (a result of the warming) and increasing ocean temperatures (which also feed back to affect the weather) also lead to 

changes in ocean currents. Under normal conditions, warm ocean waters are pulled 

poleward to replace cold waters that sink to the ocean depths in high latitudes. As 

these waters are pulled poleward, for example in the Gulf Stream, heat is given off 

that tends to keep Europe relatively warm in winter, given its latitude. As climate 

53 

change prevents ocean waters in high latitudes from cooling as much, the rate of 

sinking waters declines, and so less warm water is pulled poleward, providing less 

winter heat. While this slows the human-induced warming rate in Europe, it leaves 

that heat in lower latitudes, causing those regions to be warmer and even more 

moisture to evaporate, moisture that is likely to result in more intense rainfall 

events. Slowing the generation of oceanic deep water also slows the transport of dissolved CO2 into the deep ocean, releasing somewhat the oceanic brake on the pace 

of global warming. 

Fisheries, marine mammals, seabirds, and other marine life will all be significantly affected by these changes. Both the increasing temperature and freshening 

of upper ocean waters in some regions by increased precipitation will tend to increase stratification of the upper ocean, affecting the vertical distribution and productivity of biological activity.23 Shifts in fisheries will occur (and some changes are 

already being observed) as ocean temperatures shift and changes in abundance will 

occur as the amounts of upwelling nutrients and associated biological activity are 

reduced. The retreat of sea ice will also lead to changes in fisheries, as the ice edge 

is normally a very productive site as a result of the release of nutrients from the 

melting ice and the protection from intense waves provided by the ice itself. Marine 

mammals, including walrus, seals, and polar bears, depend on the presence of sea 

ice to raise their young and to hunt for food, and the retreat of ice is already having 

a significant impact.24 The shifts in ocean conditions, both of sea ice and of biological activity, are also starting to have effects on sea birds, which are also facing increasing competitive pressures from birds that normally are shifting northward as 

warming increases. 

An added result of sea ice retreat will be the potential for greater access by ships. 

The melting back of sea ice is already near to opening the Northern Sea Route that 

would connect the Atlantic and Pacific Oceans via open water north of Eurasia. Not 

only would such a route cut shipping time significantly, but the route will also increase seasonal access to arctic resources, both below coastal waters and on land 

(although, perversely, the summer melting of the permafrost will make transport 

over land much more difficult). Already the Northwest Passage is becoming navigable for icebreakers and in the decades ahead greater access should be possible. 

Environmentally, such access will greatly increase the risk of contamination from 

spills and other pollution, and there is virtually no experience or effective approach 

for cleaning up such spills. Politically, the increased access is already raising questions of sovereignty, ownership of coastal zone resources, and rights to the shifting 

fisheries that will result. The identification of such issues as part of the Arctic Climate Impact Assessment formed the basis of the policy guidance document that was 

prepared by the Arctic nations as a framework for future discussions.25

Overall, human-induced climate change is thus already having significant effects 

on the ocean, the weather systems that the ocean generates, and on the biological 

systems that are dependent on its resources. Adding on the impacts of sea level rise 

on the coastal environment, which is treated below, the global oceanic environment 

on which we all depend is already screaming, at least in a figurative sense, for actions to greatly slow the pace of change, especially as roughly an equal amount of 

change as has already occurred is almost certain to result as a consequence of past 

human activities. 

Interactions and Impacts Linking Climate Change and the Terrestrial 

Environment 

Changes in both the CO2 concentration itself and in the climate will affect terrestrial systems. Because CO2 is needed by plants to grow, the increase in its concentration will, as a whole, enhance plant growth and allow the stomata (pore openings) on the undersides of leaves to open less, allowing less harmful air pollution 

in and less moisture out, thereby improving the overall health and water use efficiency of plants. As a general result, the higher CO2 concentration will thus lead 

to greater carbon uptake and enhanced storage as plant material and in soils as 

long as nutrients and sufficient soil moisture are available. Recent studies suggest 

that the CO2 fertilization effect will be limited by tropospheric ozone concentrations 26 as well as the availability of nitrogen in ecosystems.27

However, different plants respond quite differently. Under conditions with adequate moisture and nutrients, many types of crops (key exceptions are maize, millet, 

sorghum, and sugar cane) respond quite strongly to the increase in the CO2 concentration, but then so too do many weedy plants, necessitating additional control 

measures. Assuming that farmers can overcome problems with weeds and increased 

occurrence of pests and that moisture amounts are sufficient, the per acre yield of 

many food crops is likely to increase by tens of percent.28 It is for this reason that 

the IPCC and other assessments suggest that overall global food production will inVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00057 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
54 

crease, at least until the CO2 concentration gets much higher when the effect can 

saturate or even changeover (i.e., become essentially toxic). Simple economic analysis would then suggest that with more agricultural production, food prices will drop 

and that there will be sufficient food, at least for those who can afford it, providing 

a net economic benefit to society. However, the situation in the real world is a good 

bit more complex. In the U.S., for example, overproduction currently leads to the 

need for subsidies as a result of overproduction, and so an increase in productivity 

and a decrease in commodity prices may well lead to calls for larger subsidies. With 

the climate also changing, there will also be a constant need to adjust seed strains 

to ensure optimal productivity,29 creating greater needs for support of crop development programs at, for example, the land grant universities. 

In addition, while productivity will go up in both good and marginal farming 

areas, the increase will be greater in absolute amount in the better farming areas, 

and so the economics of farming in marginal areas is likely to worsen, leading potentially to the abandonment of farming in such areas unless a switch can be made 

to other crops for which there is demand (e.g., a non-food crop that can be used to 

produce biofuels). For those now growing niche crops (e.g., crops such as apples and 

broccoli in cool summer regions such as upstate New York and New England; tomatoes in regions where nighttime temperatures are cool enough for fruit to set; etc.), 

warming is likely to make such regions uncompetitive for continued production of 

these crops. Because soils are typically not fertile enough to compete economically 

with regions now growing warm season crops, farming in such regions is also likely 

to be threatened. Thus, while overall food production in regions such as the U.S. 

is projected to increase, there are likely to be hard times for many farmers (and the 

rural communities associated with them) as adjustments occur. Lost in the transformation is likely to be the effective role present-day farmers play in caring for the 

land, which is likely to create ecological challenges because returning such regions 

as the southern Great Plains to their pre-farming vegetation is unlikely to be successful due to the altered climatic conditions. 

For natural systems such as forests and grasslands, the situation is more problematic. Each ecosystem type has a set of preferred conditions, as is evident from 

the changing distributions of types of forest ecosystems going poleward or up a 

mountain. As climatic conditions shift, the preferred ranges for each type of ecosystem will shift, and numerical models that simulate this process indicate that the 

projected changes in climate over the 21st century will have profound effects. Starting from the Arctic (and focusing on the coarsest subdivision of ecosystem types), 

the tundra, which is summer home and nesting ground for many migrating birds 

and mammals, will be squeezed against the Arctic Ocean as the boreal forest becomes established further and further to the north. Across the United States and 

Canada, temperate forests and grasslands will push northward, with the northeast 

mixed forest giving way to more temperate vegetation and with forests giving way 

to savanna and grasslands in regions where precipitation does not increase enough 

to supply the needed moisture in the face of rising temperatures. For the southeastern and southwestern U.S., this balance will be particularly important. As described in the U.S. National Assessment, if the summertime conditions become 

warmer and moister, the southeastern mixed forest can persist, but if precipitation 

does not increase sufficiently, the soils will dry and the temperatures will increase 

even more, creating a situation where more frequent fires become likely to accelerate the transition to a sparser savanna woodland situation.30 In the southwestern 

United States, increased precipitation, particularly in the winter, may be sufficient 

to increase biological productivity in desert areas, allowing greater vegetation 

growth in winter. While seemingly beneficial, if summers become hotter and remain 

dry, the potential for increased fire is significant (e.g., increased wintertime growth 

of chaparral would likely only increase the likelihood of periodic fires, which can be 

particularly threatening to communities in the West).31

While adapting to a situation of relatively slowly shifting ecosystems on the continental scale may seem comparable to adapting to the reforestation of the Northeast 

over the 20th century, the actual situation on the local scale, both for wildlife and 

for communities, is likely to be much more challenging. This is the case because 

there are significant variations in the response of the different plant species that 

make up the ecosystems to the changes in CO2 and climate, and this will mean that 

the preferred ranges of different species will shift by different amounts and at different rates, thus pulling apart current ecosystems without there becoming stable 

climatic conditions in which new ecosystems can evolve—instead, everything will be 

changing at once. 

Determining the thresholds that might lead to abrupt changes in the functioning 

of natural systems is, however, particularly difficult, and there are likely to be 

thresholds or tipping points that initiate a sequence of changes beyond which sysVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00058 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
55 

tems are likely to collapse. For example, a temperature increase of about 1°C per 

decade since 1970 in the Kenai Peninsula in Alaska has caused permafrost melting 

and allowed the over-wintering of spruce bark beetles and the influx of additional 

disease vectors, weakening the trees, and enhancing the extent and intensity of 

wildfire. Together, these effects have led to the sudden and widespread loss of the 

white spruce forest, and to a situation in which, even were the new climatic conditions stable, it would take centuries for new species to develop into a new, fully mature ecosystem; with stable conditions not likely for at least many decades, development of a new, mature forest system is likely far off in the future. As another example of the sensitivity of extant ecosystems, a massive die-off of pinyon pine (Pinus 

edulis) covering 12,000 square kilometers in the southwestern United States was observed during the recent severe drought. Although the soil moisture deficit was no 

worse than the one endured in the 1950s, the higher average temperature appears 

to have combined with the extreme dryness to make the trees more vulnerable to 

attacks from bark beetles.32

Increased frequency of droughts, wildfires, floods, and other extremes, including 

greater damage from increased and more persistent winds and precipitation from 

tropical cyclones,33 are other types of changes that have the potential to exceed the 

adaptive capacity of existing ecosystems. In addition, more frequent fires and the 

reduced productivity of some ecosystems will limit the amount of carbon being taken 

up and stored by the biosphere, thus leaving a larger fraction of the emitted CO2

to exacerbate global warming. For example, the recent Indonesian fires driven by 

ENSO drying and human land use changes led to significant releases of CO2 to the 

atmosphere. A recent international comparison of coupled carbon climate simulations 34 found that all of the models projected some destabilization of tropical ecosystems, leading to soil drying, reduced plant/tree growth, and increased occurrence 

of fire and net emission of CO2 to the atmosphere, thereby accelerating warming 

(positive feedback loop).35 Models typically suggested that by 2100 these ‘‘carbon-climate’’ feedbacks would lead to the atmospheric CO2 concentration being higher by 

20 to 200 ppmv 36 and additional warming of 0.1 to 1.5°C, with the worst-case model 

scenario projecting the complete die off of the Amazon rain forest. These feedbacks 

are not yet well understood or represented, requiring coupled treatment of climate 

change, CO2 fertilization, nitrogen limitation, and the ability of trees to tap deep 

soil horizon water; however, these processes do indicate the potential for the likely 

outcome being more toward the upper end of the IPCC range of possibilities.37

Because projected shifts in the frequency, timing, intensity, and location of precipitation will lead to all sorts of challenges, issues relating to freshwater resources, 

although of a variety of types, were a common thread across all regions in the U.S. 

National Assessment (see Table 1 for a brief summary of key regional consequences). For example, the increased likelihood of additional wintertime precipitation in the western U.S., as projected in both models used in the U.S. National Assessment, increases the potential for mudslides and high river levels as well as increasing the likelihood of mountain precipitation falling as rain, causing accelerated 

loss of the snowpack, a further increase in runoff and an even greater likelihood of 

flooding. At the same time, warmer temperatures will lead to a rise in the snowline 

and, on average, a reduction in the springtime snowpack that is so vital for sustaining stream and river flows into the summer. For the rest of the U.S., projections 

indicate a continuation of the shift of precipitation toward more precipitation falling 

in the more intense (i.e., convective) rainfall events. Reducing the time for rainfall 

to seep into aquifers has the effect of increasing runoff, especially once the upper 

layer of soil has become saturated, thereby increasing the likelihood of high river 

levels and flooding. Warmer summertime temperatures, and a greater interval between significant rainfall events, are projected by many of the models to lead to increased evaporation of soil moisture in the Great Plains, and so a more rapid onset 

of drought conditions. For the Great Lakes, most models project a few foot lowering 

of lake levels as the increase in summertime evaporation exceeds the increase in 

winter precipitation, significantly impacting community, recreational and commercial use of lake waters.38 Reduced duration and extent of snowfall will also affect 

the Northeast and other areas, likely shortening the ski season and lengthening the 

time for warm weather recreational use of the landscape, assuming drying and fire 

do not become threats. 

In the Arctic, the melting back of snow cover, river ice, and permafrost, combined 

with offshore melting back of sea ice, will have significant effects on wildlife and 

on movement generally across the region. For many types of wildlife, the snow cover 

provides protection and even habitat, and climate change is likely to break vital 

links (e.g., lemmings and voles survive the winter mostly between the snow layer 

and the underlying tundra, and their loss would deplete food resources for snowy 

owls and foxes, etc.). Reindeer and caribou depend on the snow cover to protect 

56 

vegetation that serves as winter feed, and episodic freeze-thaw conditions can create 

ice crusts that cannot be easily broken, reducing access to the food necessary to survive. The migrating herds also depend on frozen river ice in springtime to cross rivers along migration routes to summer breeding grounds.39 Warmer conditions are 

already leading to new species appearing in the Arctic, and these new species will 

tend to push existing species northward, likely eventually to extinction as the land 

ends and the Arctic Ocean begins. 

In addition, the melting of permafrost (and frozen sediments on the continental 

shelves) has the potential to release large amounts of methane (CH4) that is tied 

up in hydrates. On a per molecule basis, methane is roughly 20 times as effective 

as trapping infrared radiation as is a CO2 molecule, which is why there is so much 

attention being devoted to human-induced changes in methane concentrations 

(human contributions have caused about a 150 percent increase in the preindustrial 

CH4 concentration). While permafrost melting has begun, determining how much 

CH4 is being released has proven quite difficult and so the IPCC projections do not 

yet account for the potential warming influence of such releases, but the potential 

for substantial releases is quite significant, especially because warming in the Arctic 

is projected to be greater than for the world as a whole. 

Continued warming and changes in snowfall are also likely to further increase the 

ongoing retreat of mountain glaciers and the great ice sheets. In virtually all regions 

of the world, including on high tropical mountains, glaciers are retreating at a rapid 

rate. Because the annual glacier runoff in many cases serves as water resources for 

wildlife and communities, the eventual loss of the glaciers is likely to have very significant consequences in many regions around the world. The area of the Greenland 

Ice Sheet that melts each year is also increasing, and satellite observations indicate 

that ice mass is decreasing.40 What appears to be happening is that rather than 

small puddles forming and then refreezing in the fall, larger puddles are forming, 

and then finding channels and crevasses to flow to the bedrock and eventually into 

the ocean, allowing a greater fraction of the increase in downward infrared radiation 

caused by the higher greenhouse gas concentrations to go into melting of ice as opposed to the very energy intensive process of evaporation of water. The situation is 

much like what would happen if one of those decorative ice statues on banquet tables were taken out of a freezer for longer and longer intervals—if out for only a 

short period, the thin meltwater layer on the statue might refreeze when the statue 

is put back in the freezer; however, if kept out longer, the meltwater created each 

time would be lost, and soon there would be no ice statue at all.41

Projections are that high-latitude warming of a few degrees Celsius (so perhaps 

5°F), which is projected for the second half of the 21st century, would be likely to 

lead to the melting of roughly half of the Greenland Ice Sheet over a period of up 

to several centuries,42 mirroring a similar event that occurred during the last interglacial,43 likely mainly as the result of a particular set of variations in the Earth’s 

orbit at that time that brought comparable warmth to high northern latitudes. The 

effects on sea level of such extensive changes are discussed in the next section. 

While much of the above discussion has focused on the projected changes in seasonal to annual timescale changes, what really has most effect on people and the 

environment are the extremes of the weather that are combined to get the changes 

in the averages. The weather (i.e., the instantaneous state of the atmosphere) is determined by the interaction of all of the various forcings and gradients in the global 

system. Observations indicate that day-to-day weather conditions tend to vary about 

the mean conditions in a more-or-less standard way, creating a bell-shaped distribution of conditions with a few instances much above and below the average and a 

greater likelihood of the conditions being near the average expected at each time 

of year. The projected change in climate will shift this distribution, moving the average higher, and thereby creating a much greater likelihood that conditions will exceed a particular threshold (e.g., 90 or 95°F). The likelihood of presently unusual 

events could also be changed if the shape of the bell-like distribution is changed, 

which could occur, for example, if the characteristics of the global circulation are 

changed (e.g., by moving the winter jet stream relative to mountain ranges such as 

the Himalayas, or by altering the oceans in ways that affect the irregular cycling 

or intensity of El Nin ̃ o or La Nin ̃ a events). 

As a result of the changes in climate, conditions such as heat waves (which exacerbate the heat index and thermal stress in cities 44) and drought conditions favorable for wildfires are expected to become more frequent and more intense. In fact, 

Dai et al. (2004) calculate that the amount of land experiencing severe drought has 

more than doubled in the last 30 years, with almost half of the increase being due 

to rising temperatures rather than decreases in rainfall or snowfall.45 Not surprisingly, therefore, observations indicate that wildfires have been increasing on all continents, particularly sharply in North America, and projections are that this trend 

57 

is likely to intensify with further increases in surface temperature.46 In addition, 

freeze events, which are important to controlling many types of pests and associated 

diseases, are projected to be less likely. As already mentioned, the occurrence of 

more intense and more frequent heavy rainfall events is likely to increase the occurrence of flooding. Analyses by Milly et al. (2002) indicate that the frequency of very 

large floods has increased substantially during the 20th century, which is consistent 

with climate model simulations, and modeling studies suggest that the trend will 

continue in the future.47 With respect to the potential severity of this type of effect, 

results from the Canadian climate modeling group cited in the U.S. National Assessment indicate that the return period of what are now once in a hundred year events 

will, by the end of the century, likely be reduced to about once every 30 years, with 

even more severe events occurring once every hundred years. In that much of society’s infrastructure is only designed to withstand once in a hundred year events, 

having more severe events occurring more often than once a century is likely to increase the likelihood of very damaging events,48 causing very adverse and costly impacts for both society and the environment. 

Some media reports and criticisms by skeptics question the rising concern about 

the increasing risks from more intense and more frequent occurrence of extreme 

weather events, indicating that no specific event can be attributed to global warming. To better understand the situation, consider the simple analogy of the Earth’s 

weather being equivalent to a pot of slowly boiling water, with each bubble indicating an extreme event somewhere across the globe. If the heat under the pot is 

turned up, there will be more bubbles, some of which are the size of the previous 

largest bubble and perhaps some even larger. There is no way to say that any particular bubble was due to the increased heat or was bigger because of it, yet clearly 

the intensified bubbling is due to the additional heat. Now, the real world situation 

is further complicated by seasonal changes (roughly equivalent to the heat being 

slowly turned up and down, but each time to higher levels), spatial linkages resulting from the oceanic and atmospheric circulations (roughly equivalent to adding noodles to the boiling water), and the presence of mountains and other geographic features (roughly equivalent to having a pot of varying shape and thickness); as a result formally detecting the changes in extreme events is indeed a challenge. But 

there is no question that adding heat to the system will lead to greater extremes 

(were the subtropics not so warm, the incidence of tropical cyclones would be much 

less). 

Consequences at the Coastal Interface of the Terrestrial and Marine 

Environments 

At coastlines, the consequences of the changes in marine and terrestrial components come together. Because the coastal region provides habitat to so many species, 

from shrimp to shore birds, and from plant species to humans, past and projected 

changes occurring in this boundary environment have particular importance for the 

environment and society. 

Bays, inlets, estuaries, barrier islands, marshes, wetlands, and more provide habitat to a wide range of species, in some cases year-round and in other cases at particular times as species migrate from one region to another. These regions are 

breeding grounds for fish and fowl, and those, including humans, that live off of 

them. The particular conditions each species needs results from the balance between 

the saline ocean waters and the terrestrial freshwaters, all mixed by the tides and 

ocean currents and moderated and mixed by the particular weather conditions ranging from mild sea breezes to raging storms. Nutrients are provided by the oceanic 

and river flows and by atmospheric deposition, all then cycled through by the chain 

of living plants and animals (including both terrestrial and marine life). Productivity has been able to develop as a result of the relative stability of the shoreline 

environment, with niches being filled to make optimal use of available resources. 

Climate change is not the only stress that is now being imposed on this environment. Harvesting, air and water pollution, encroachment, toxics, excessive nitrogen 

deposition, oxygen deprivation, and more are all creating stresses, and now comes 

sea level rise and climate change (i.e., warming, changes in precipitation that alter 

runoff, intensified storms, changes in winds and ocean currents, and more). Sea 

level has been roughly stable for the past several thousand years, yet has recently 

begun to rise. Warming of ocean waters (which leads to their expansion, just as 

mercury expands to fill a thermometer as the temperature increases) and water 

added to the ocean, likely mostly from melting of mountain glaciers, caused global 

sea level to rise 4–8 inches (10–20 cm) during the 20th century.49 For the 21st century, the early projections have been that sea level will go up by another 12–20 

inches (30–50 cm); 50 with the apparent acceleration in the melting of the Greenland 

Ice Sheet that has been observed,51 the Arctic Climate Impact Assessment conVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00061 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
58 

cluded that projections of sea level rise for the 21st century could quite possibly exceed 20 inches (50 cm), reaching toward the upper limit of the IPCC projections. 

What is particularly problematic is that the factors contributing the most to sea 

level rise, namely thermal expansion and the ultimate melting of the Greenland and 

West Antarctic Ice Sheets, are likely to continue to contribute to sea level rise for 

centuries after the rise in greenhouse gases is halted, meaning that significant 

areas of the shoreline will be inundated and lost over coming decades and centuries, 

and that protection of the most valuable regions through levee construction needs 

to receive early attention.52 To date, no nation has prepared for sea level rise of a 

meter or more within a century, but the possibility warrants appropriate planning 

beyond normal disaster preparedness. 

While the rise in sea level itself might seem small, when amplified by the effects 

of storms creating waves and storm surges, the situation is particularly threatening. 

In the Arctic, the melting away from the shore of the sea ice away has allowed winter waves to pound the barrier islands, causing significant erosion. This is particularly a problem because coastal regions are where many native communities have 

been located, often for thousands of years, in order to harvest the bounty of both 

the land and the ocean. The most endangered community is currently Shishmaref, 

which is being eroded away so rapidly that community relocation has already started. As the Government Accountability Office has projected,53 relocation of all the endangered villages is going to be very costly. Both the climate changes themselves 

and the relocations will lead to substantial disruption of subsistence harvesting 54

and indigenous culture and traditions that have sustained these communities 

through thousands of years. 

For coastal regions exposed to hurricanes and the waves and the storm surges 

that they create, the danger is also very great. While international assessments 

have generally suggested that developing countries are more vulnerable to global 

warming than developed nations because they lack the resources to be able to adapt, 

the developed nations have at risk far greater investments in coastal infrastructure, 

including roads, highways, railroads, airports, ports, sewage treatment facilities, 

and residential and commercial buildings. Many of these structures are fully exposed to the oceans, unlike New Orleans, which at least at one time was protected 

by extensive wetlands. With the power and duration of intense hurricanes observed 

to be increasing, and with greater changes likely ahead as ocean temperatures continue to rise, the coastal region is particularly at risk. While building levees is likely 

to be able to work for a while, if sea level rise reaches a few meters within a few 

centuries, retreat is ultimately going to be required in many regions. Disrupted 

coastlines are also likely to disrupt the resident and migrating wildlife. While some 

new wetlands may be formed further inland, it is unlikely that such new areas will 

be as extensive or as able to fill the many roles of existing areas, especially as the 

process of coastal inundation will be continuous rather than allowing full development at some altered, but fixed, change in sea level. 

Summary and Concluding Thoughts 

While the discussion above has focused on the great variety of changes and interactions that the increase in the CO2 concentration and changes in climate are leading to (and the above list is only a sampling), what will be experienced by the environment and society will be all of these changes together, plus the impacts of all 

of the other changes going on, ranging from air and water pollution to resource utilization and land cover change. While a number of these can be (and are being) ameliorated by regulations and policy, climate change presents several unique aspects. 

First, climate change will keep growing and growing—it is an influence that can 

only be slowed, not reversed (at least in any reasonable time horizon). Second, it 

is fully global, and because the world is environmentally and economically interconnected, impacts in one location can create impacts in other locations. And third, 

the changes are larger and occurring more rapidly than can be accounted for using 

any analogs to the past, making very real the potential for surprises, unexpected 

changes, unidentified thresholds, and tipping points. As Australian author and scientist Barrie Pittock has put it, ‘‘Uncertainty is inevitable, but risk is certain.’’ 55

For the natural world, change is already evident. Analyses by Parmesan and Yohe 

(2003) indicate with very high confidence that a large fraction of the plant and animal species studied are showing a response consistent with that expected to result 

from changes in climate.56 The types of responses include shifts in range (e.g., the 

Inuits are spotting types of birds never seen before that far north), changes in number and vitality (e.g., the polar bear population around Hudson’s Bay), and unprecedented susceptibilities (e.g., to pest outbreaks). There is no question that the natural 

world is changing, and the main question is how much change can occur before 

changes in keystone species begin to cause the collapse of ecosystems (e.g., of the 

59 

Amazon rainforest 57) and significant reductions in the ecosystem services (e.g., air 

and water purification, food and fiber generation, fish and shrimp production) that 

these systems provide to society. Of particular concern are how all of these changes 

affect migrating species from birds to butterflies and fish to whales, for they have 

generally developed a dependence on a timeline of resources at particular locations 

in order to survive, and significant loss could occur from substantial disruption of 

any of them. 

While modern society may seem less dependent on the natural world, many linkages remain, not only between communities and nearby ecosystems, but also with 

conditions around the world. Increased temperatures (along with higher absolute 

humidity—so much higher heat indices) will stress those not able to stay in and pay 

for air-conditioned space. While those in colder climates that have tight houses can 

readily transfer savings on heating bills to pay for increased cooling, those in more 

open homes in presently southern climates will have to invest in considerable structural upgrading to make air-conditioning a viable remedy. That the cost of upgrading will be high, and the need for it greatest among the poor, will create a serious 

issue of equity, with the least fortunate responsible for the lowest energy use yet 

suffering the largest consequences. 

The effects will not only be personal. Not only do modern societies draw resources 

and food from ecosystems and countries around the world, but products also come 

from around the world and investment portfolios typically include a mix of international stocks, coupling one’s economic state to the state of the world. In addition, 

with people traveling extensively for business and pleasure, the health of people 

around the world is interconnected, and what happens in one location can soon affect those in other locations. In that warm conditions are generally more favorable 

for the presence of disease vectors such as mosquitoes, warming will lead to the loss 

of the ally of freezing conditions for helping to control mosquito populations. As a 

result, except in regions (such as the U.S.) where rigorous public health practices 

and community building standards have over time separated the disease from the 

disease vector and from people, warming and increased precipitation are likely to 

exacerbate the likelihood of exposure to disease vectors.58 Even in countries such 

as the U.S., isolated occurrences are likely given the magnitude of international 

travel, and so extra resources will have to be devoted to maintaining high standards 

and quickly addressing new infestations (e.g., by spraying for mosquitoes). Changes 

in the distribution and level of activity of various plant species can also exacerbate 

health problems, as for example the increased production of pollen that can exacerbate incidence of asthma.59

The shifting climatic patterns and rising sea level are likely to be most problematic for small countries and other similarly sized entities. For island nations made 

up mainly of coral atolls, rising sea level and higher storm surges are already having deleterious effects on aquifers, and continuing sea level rise is likely to inundate 

several island nations over the coming century. For small countries, especially those 

that have focused on growing a particular crop, shifting climatic patterns are likely 

to require changes in crop species, which is likely to be difficult to compete as there 

will likely be the need to break into new markets. Whereas many indigenous peoples, including the American Indian, have long traditions of adaptation, at the root 

of previous successes was often the ability to relocate; with tribal reservations now 

fixed, community relocation is no longer possible, and medicinal plants and other 

historic species are likely to shift to quite removed locations, negating the passed 

on ecological wisdom developed over so many generations. 

For many regions, changes in water resources will be the most important effect, 

with increased competition for reduced resources among agricultural, community, 

industrial and ecological interests. For coastal regions, sea level rise and increases 

in storm intensity will pose the most important threats, requiring both enhancement of resilience in the near-term and possible relocation in the long-term. For 

those in urban areas, the increased likelihood of heat stress conditions and higher 

air pollution levels 60 may well pose the most significant threat. Because the particular situation of each region will depend on its individual circumstances, as indicated in Table 1, it is vital that the Nation have an ongoing assessment activity that 

helps regions and sectors to understand, prepare for, and ameliorate the most deleterious circumstances. Such an effort, as is called for in the Global Change Research 

Act of 1990 [Pub.L. 101–606], was begun in earnest in 1997 with the undertaking 

of the U.S. National Assessment; that this effort was essentially terminated in 2001 

after having made significant progress in involving stakeholders in regional activities has been most unfortunate. 

What is most clear is that global climate change is underway and that the risk 

of adverse consequences for both marine and terrestrial environments is quite high. 

While it will take substantial efforts and many decades to limit emissions of greenVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00063 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
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house gases and bring climate change to a stop as called for in the U.N. Framework 

Convention on Climate Change ratified by the U.S. Senate in 1992, that virtually 

no effort is being made by the U.S. to accomplish this in the face of all the scientific 

information about impacts is most unfortunate. For the people of the Arctic and of 

the U.S. whom I have had the privilege of representing in assessment activities, I 

urge your most urgent consideration of a national effort to prepare for the inevitable 

climate change that lies ahead and to take actions to sharply limit the climate 

change that will be brought on by future emissions. 

Websites of Particular Relevance to Understanding of Climate Impacts 

U.S. National Assessment of the Potential Consequences of Climate Variability 

and Change (http://www.usgcrp.gov/usgcrp/nacc/default.htm) 

Arctic Climate Impact Assessment (http://www.acia.uaf.edu/) 

Intergovernmental Panel on Climate Change: (http://www.ipcc.ch/) 

Millennium Ecosystem Assessment: (http://www.millenniumassessment.org/en/ 

index.aspx) 

Climate Institute (http://www.climate.org/CI/index.shtml) 

Table 1: Examples of important climate change consequences affecting regions of the U.S.* 

Regions and Subregions 

Examples of Key Consequences Affecting: 

the Environment the Economy People’s Lives 

Northeast—New 

England and upstate NY, Metropolitan NY, Mid-Atlantic 

Northward shifts in 

the ranges of plant 

and animal species 

(e.g., of colorful 

maples); Coastal 

wetlands inundated 

by sea-level rise. 

Reduced opportunities 

for winter recreation such as skiing; increased opportunities for 

warm-season recreation such as hiking 

and camping; 

Coastal infrastructure will need to be 

buttressed. 

Rising summertime 

heat index will 

make cities less 

comfortable and require more use of 

air-conditioning; 

Reduced snow 

cover. 

Southeast—Central 

and Southern Appalachians, Gulf 

Coast, Southeast 

Increased loss of barrier islands and 

wetlands, affecting 

coastal ecosystems; 

Changing forest 

character, with possibly greater fire 

and pest threat. 

Increased productivity 

of hardwood forests, 

with northward 

shift of timber harvesting; Increased 

intensity of coastal 

storms threaten 

coastal communities. 

Increased flooding 

along coastlines, 

with increased 

threat from storms; 

Longer period of 

high heat index, 

forcing more indoor 

living. 

Midwest—Eastern 

Midwest, Great 

Lakes 

Higher lake and river 

temperatures cause 

trend in fish populations away from 

trout toward bass 

and catfish. 

Increasing agricultural productivity 

in many regions, 

ensuring overall 

food supplies but 

possibly lowering 

commodity prices. 

Lowered lake and 

river levels, impacting recreation opportunities; Higher 

summertime heat 

index reduces 

urban quality of 

life. 

Great Plains— 

Northern, Central, 

Southern, Southwest/Rio Grande 

Basin 

Rising wintertime 

temperatures allow 

increasing presence 

of invasive plant 

species, affecting 

wetlands and other 

natural areas; Disruption of migration 

routes and resources. 

Increasing agricultural productivity 

in north, more 

stressed in the 

south; Summertime 

water shortages become more frequent. 

Altered and intensified patterns of climatic extremes, especially in summer; 

Intensified springtime flood and summertime drought 

cycles. 

61 

Table 1: Examples of important climate change consequences affecting regions of the U.S.*— 

Continued 

Regions and Subregions 

Examples of Key Consequences Affecting: 

the Environment the Economy People’s Lives 

West—California, 

Rocky Mountains/ 

Great Basin, Southwest/Colorado River 

Basin 

Changes in natural 

ecosystems as a result of higher temperatures and possibly intensified 

winter rains. 

Rising wintertime 

snowline leads to 

earlier runoff, 

stressing some reservoir systems; Increased crop yields, 

but with need for 

greater controls of 

weeds and pests. 

Shifts toward more 

warm season recreation activities (e.g., 

hiking instead of 

skiing); Greater fire 

potential created by 

more winter rains 

and dry summers; 

Enhanced coastal 

erosion. 

Pacific Northwest Added stress to salmon populations due 

to warmer waters 

and changing runoff 

patterns. 

Earlier winter runoff 

will limit water 

availability during 

warm season; Rising forest productivity. 

Reduced wintertime 

snow pack will reduce opportunities 

for skiing, increase 

opportunities for 

hiking; Enhanced 

coastal erosion. 

Alaska Forest disruption due 

to warming and increased pest outbreaks; Reduced sea 

ice and general 

warming disrupts 

polar bears, marine 

mammals, and 

other wildlife. 

Damage to infrastructure due to permafrost melting; Disruption of plant and 

animal resources 

supporting subsistence livelihoods. 

Retreating sea ice and 

earlier snowmelt 

alter traditional life 

patterns; Opportunities for warm season activities increase. 

Coastal and Islands—Pacific Islands, South Atlantic Coast and Caribbean 

Increased stress on 

natural biodiversity 

as pressures from 

invasive species increase; Deterioration of coral reefs. 

Increased pressure on 

water resources 

needed for industry, 

tourism and communities due to climatic fluctuations, 

storms, and saltwater intrusion into 

aquifers. 

Intensification of flood 

and landslide-inducing precipitation 

during tropical 

storms; More extreme year-to-year 

fluctuations in the 

climate. 

Native People and 

Homelands 

Shifts in ecosystems 

will disrupt access 

to medicinal plants 

and cultural resources. 

The shifting climate 

will affect tourism, 

water rights, and 

income from use of 

natural resources. 

Disruption of the religious and cultural 

interconnections of 

Native people and 

the environment. 

* MacCracken, M. C., 2001: Climate Change and the U.S. National Assessment, pp. 40–43 in McGraw Hill 

Yearbook of Science and Technology 2002, McGraw-Hill, New York, 457 pp. 

ATTACHMENT 1: ARCTIC TEMPERATURE CHANGE—OVER THE PAST 100 YEARS

Released June 28, 2005 by Gordon McBean, Lead author of Chapter 2, ACIA 

Report. The authors of Chapter 2 are: G. A. McBean, G. Alekseev, D. Chen, E. 

Forland, J. Fyfe, P.Y. Groisman, R. King, H. Melling, R. Vose and P. H. Whitfield. 

This note has been prepared in response to questions and comments that have 

arisen since the publication of the Arctic Climate Impact Assessment overview document—‘‘Impacts of a Warming Arctic.’’ It is intended to provide clarity regarding 

some aspects relative to the material from Chapter 2 Arctic Climate—Past and 

Present that will appear in full with the publication of the ACIA scientific report 

in 2005. 

62 

The authors of Chapter 2 began their work in 2000. It was recognized that the 

observational data base for the Arctic is limited, with few long-term stations and 

a paucity of observations in general. Because at that time the published literature 

on Arctic temperature changes was not comprehensive nor up-to-date, it was decided to undertake a new set of calculations, based only on data sets that were fully 

documented in the literature, but updated to the present, using the documented procedures. The Global Historical Climatology Network (GHCN) data base (updated 

from Peterson and Vose, 1997) was selected for this analysis. A comparison was 

made with the Climatic Research Unit (CRU) data base (Jones and Moberg, 2003) 

because both data bases were used in the Third Assessment Report (IPCC, 2001b) 

to summarize the patterns of temperature change over global land areas since the 

late 19th century. The GHCN dataset includes selected quality controlled long-term 

stations suitable for climate change studies. The U.S. National Climate Data Center 

was asked to do the calculations since they had both datasets in their archives. 

There are several possible definitions of the Arctic depending on, for example, tree 

line, permanent permafrost, and other factors. It was decided for purposes of this 

analysis that the latitude 60°N would be defined as the southern boundary. Although somewhat arbitrary, this is no more arbitrary than choosing 62°N, 67°N or 

any other latitude. Since the marine data in the Arctic are very limited in geographical and temporal coverage, it was decided, for consistency, to only use data 

from land stations. 

The analysis showed that the annual land-surface air temperature variations in 

the Arctic (north of 60°N) from 1900 to 2002 using the GHCN and the CRU datasets 

led to virtually identical time series, and both documented a statistically significant 

warming trend of 0.09 °C/decade during that period (Figure 1). Annual land-surface 

air temperature trends were calculated for the periods 1900–2003, 1900–1945, 

1946–1965, and 1966–2003. Trends were calculated from annually averaged gridded 

anomalies using the method of Peterson et al. (1999) with the requirement that annual anomalies include a minimum of 10 22 months of data. For the period 1900– 

2003, trends were calculated only for those 5° x 5° grid boxes containing annual 

anomalies in at least 70 of the 104 years. The minimum number of years required 

for the shorter time periods (1900–1945, 1946–1965, and 1966–2003) was 31, 14, 

and 26, respectively. 

63 

Figure 1. Annual anomalies of landsurface air temperature (°C) from 60–90°N 

for the period 1900–2002. Anomalies are relative to a 1961–90 base period. The 

smoothed curve was created using a 21-point binomial filter giving near decadal 

averages. Panel (a)(upper) depicts the GHCN time series (updated from Peterson and Vose, 1997), and panel (b)(lower) depicts the CRU time series (Jones 

and Moberg, 2003). 

In response to critical comments about the ACIA analysis of the temperature 

record, it is important to note that the choice to use the CHCN dataset was made 

before the analysis was done, before the Polyakov et al. (2002) paper was published 

and based on the logical arguments that it was the most comprehensive land-station 

data base available and was well documented in the literature. As noted, the other 

well-documented data base, of the CRU, gave virtually identical results. 

It needs to be stressed that the spatial coverage of the region north of 60° N is 

quite varied. During the period (1900–1945), there are 7 grid boxes meeting the requirement of 31 years of data in the Alaska/Canadian Arctic/West Greenland sector. 

The largest number of grid boxes is in the North Atlantic sector (East Greenland/ 

Iceland/Scandinavia) with 13 grid boxes. There were 10 grid boxes over Russia. The 

coverage for periods since 1945 is more uniform. Based on these analyses, the annual land-surface air 23 temperature (°C) from 60–90°N, smoothed with a 21-point 

binomial filter giving near decadal averages, were warmer in the most recent decade 

(1990s) than they were in the 1930–1940s period. 

The analysis of Polyakov et al. (2002) showed the 1930–1940s period warmer than 

the most recent decade. They used individual stations and the distributions of stations, according to the Figure 1 in their paper, was quite varied for different time 

periods. The total number of stations of more than 65 years is 8 stations in the 

Alaska/Canada/West Greenland sector compared to 43 stations in the North Atlantic/Russian sector. Over the whole period of record, their analysis considered 18 staVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00067 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE

cor1.eps
64 

tions for the Alaska/Canada/West Greenland sector compared with 50 stations from 

the North Atlantic/Russian sector. The Polyakov paper also considered only maritime (or coastal) stations north of 62°N, while the analysis presented in Chapter 2 

of the ACIA report considered all land stations north of 60°N. It should be noted 

that several of the locations of greatest warming in recent decades are apparent as 

a result of the continental stations between 60° and 62°N (in Russia, Canada and 

Alaska). 

Another important paper is that of Johannessen et al. (2004) who found, with a 

dataset extensively augmented by Russian station data not previously available, 

that the ‘‘early warming trend in the Arctic was nearly as large as the warming 

trend for the last 20 years’’ but ‘‘spatial comparison of these periods reveals key differences in their patterns’’. Their analysis, consistent with the analysis presented 

in the ACIA Chapter 2, showed that average annual temperatures were higher in 

the most recent decade than in the 1930–1940 period. Further, the pattern of temperature increases over the past few decades, they note, is different and more extensive than the pattern of temperature increases during the 1930s and 1940s, when 

there was weak (compared to the present) lower-latitude warming. 

Chapter 3 of the ACIA report, entitled ‘‘The Changing Arctic: Indigenous Perspectives’’ documents the traditional knowledge of Arctic residents and indicates that 

substantial changes have already occurred in the Arctic and supports the evidence 

that the most recent decade is different from those of earlier in the 20th century. 

Although all data bases suffer from a lack of data in the Alaska/Canada/West 

Greenland sector except for the last 50 years, Polyakov et al. (2002), ACIA Chapter 

2, Johannessen et al. (2004), Serreze, et al. (2000) and other analyses all show that 

the recent decades are warm relative to at least most of the period of instrumental 

record. 

The rate of warming in the recent decades is also much greater than the average 

over the past 100 years (Figure 2). Least-squares linear trends in annual anomalies 

of arctic (60° to 90° N) land-surface air temperature from the GHCN (updated from 

Peterson and Vose, 1997) and CRU (Jones and Moberg, 2003) datasets for the period 

1966–2002 both gave warming rates of 0.38 (°C/decade). This is consistent with the 

analysis of Polyakov et al. (2002) and confirmed with satellite observations over the 

whole Arctic, for the past 2 decades (Comiso, 2003). 

65 

Figure 2. Trends in land-surface air temperatures (solid lines) and their 95 percent significance levels (dashed lines) over the past 120 years for (a) 60° to 90° 

N and (b) 0 to 60° N (data from the GHCN dataset, updated from Peterson and 

Vose, 1997). 

The modeling studies Johannessen et al. (2004) showed the importance of anthropogenic forcing over the past half century for modeling the arctic climate. ‘‘It is suggested strongly that whereas the earlier warming was natural internal climate-system variability, the recent SAT (surface air temperature) changes are a response to 

anthropogenic forcing’’. A new paper, published after completion of the ACIA Chapter, by Bengtsson et al. (2004) states in its summary, with reference to the warming 

of the 1930–1940s: ‘‘This study suggests that natural variability is a likely 

cause . . .’’ 

As stated by the IPCC (2001b), model experiments show ‘‘a maximum warming 

in the high latitudes of the Northern Hemisphere’’. In reference to warming at the 

global scale, the IPCC (2001a) also concluded, ‘‘There is new and stronger evidence 

that most of the warming observed over the past 50 years is attributable to human 

activities’’. Karoly et al. (2003) concluded that temperature variations in North 

America during the second half of the 20th century were probably not due to natural variability alone. Zwiers and Zhang (2003) were able to detect the combined 

effect of changes in greenhouse gases and sulfate aerosols over both Eurasia and 

North America for this period, as did Stott et al. (2003) for 25 northern Asia (50– 


cor2.eps
66 

70° N) and northern North America (50–85° N). In any regional attribution study 

for the Arctic (which has not yet been published), the importance of variability must 

be recognized. In climate model simulations, the arctic signal resulting from humaninduced warming is large but the variability (noise) is also large. Hence, the signal 

to noise ratio may be lower in the Arctic than at lower latitudes. In the Arctic, data 

scarcity is another important issue. However, it is implausible to conclude that the 

warming of the recent decades is not of anthropogenic origins. 

In the context of this report, the authors agreed on the following terminology. A 

conclusion termed as ‘‘very probable’’ is to be interpreted that the authors were 90– 

99 percent confident in the conclusion. The term ‘‘probable’’ conveys a 66–90 percent 

confidence. 

The conclusions of Chapter 2 were that: 

‘‘Based on the analysis of the climate of the 20th century, it is very probable 

that the Arctic has warmed over the past century, although the warming has 

not been uniform. Land stations north of 60° N indicate that the average surface temperature increased by approximately 0.09 °C/decade during the past 

century, which is greater than the 0.06 °C/decade increase averaged over the 

Northern Hemisphere. It is not possible to be certain of the variation in mean 

land-station temperature over the first half of the 20th century because of a 

scarcity of observations across the Arctic before about 1950. However, it is probable that the past decade was warmer than any other in the period of the instrumental record.’’ 

Polar amplification refers to the relative rates of warming in the Arctic versus 

other latitude bands. Using comparable data sets (the GHCN dataset), the warming 

for land stations over the region north of 60°N, is almost double that for stations 

in the latitude bands 0–60°N (Figure 2). The conclusions of Chapter 2 were that: 

‘‘Evidence of polar amplification depends on the timescale of examination. Over 

the past 100 years, it is possible that there has been polar amplification, however, over the past 50 years it is probable that polar amplification has occurred.’’ 

References 

Bengtsson, L., V.A. Semenov and O.L. Johannssen, 2004; The early twentieth-century warming in the Arctic—a possible mechanism. J. Climate, 17, 4045– 

4057. 

Comiso, J., 2003. Warming trends in the Arctic from clear sky satellite observations. 

Journal of Climate, 16:3498–3510. 

IPCC, 2001a. Climate Change 2001: Synthesis Report. A Contribution of Working 

Groups I, II, and III to the Third Assessment Report of the Intergovernmental 

Panel on Climate Change. Watson, R.T., and the Core Writing Team (eds.). 

Cambridge University Press, 398 pp. 

IPCC, 2001b. Climate Change 2001: The Scientific Basis. Contribution of Working 

Group I to the Third Assessment Report of the Intergovernmental Panel on 

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ENDNOTES 1Prepared in cooperation with Dr. Michael MacCracken, chief scientist for climate 

change programs at the Climate Institute, Washington DC, and Dr. Rosina 

Bierbaum, Dean of the School of Natural Resources and Environment at the University of Michigan in Ann Arbor. 2 National Assessment Synthesis Team, 2000: Climate Change Impacts on the 

United States: The Potential Consequences of Climate Variability and Change: Overview Report, U. S. Global Change Research Program, Cambridge University Press, 

Cambridge UK, 154 pp. 

[Also see Foundation Report, U.S. Global Change Research Program, Cambridge 

University Press, Cambridge UK, 612 pp. published in 2001]. The most significant 

results of the National Assessment were summarized in the U.S. Climate Action Report—2002, which was submitted to the U.N. under the Framework Convention on 

Climate Change as the Third National Communication of the United States of 

America (thus representing the official position of the U.S. Government in a document formally approved by all of the involved agencies and departments); this document is available from the U.S. Government Printing Office website at http://bookstore.gpo.gov and is posted at http://yosemite.epa.gov/oar/globalwarming.nsf/content/ResourceCenterPublicationsUSClimateActionReport.html. 3 Arctic Climate Impact Assessment (ACIA), 2004: Impacts of a Warming Arctic: 

Arctic Climate Impact Assessment, Cambridge University Press, 140 pp. [Also see 

ACIA, 2005, Cambridge University Press, 1042 pp.] 4The Arctic Council was established on September 19th, 1996 in Ottawa, Canada. 

The Arctic Council is a high-level intergovernmental forum that provides a mechanism to address the common concerns and challenges faced by the Arctic governments and the people of the Arctic as a means of improving the economic, social 

and cultural well being of the north. The national members of the Council are Canada, Denmark, Finland, Iceland, Norway, the Russian Federation, Sweden, and the 

United States of America; the Association of Indigenous Minorities of the North, Siberia and the Far East of the Russian Federation, the Inuit Circumpolar Conference, the Saami Council, the Aleutian International Association, Arctic 

Athabaskan Council and Gwich’in Council International are Permanent Participants 

in the Council. Many additional entities participate through a provision that provides for non-arctic states, inter-governmental and inter-parliamentary organizations and nongovernmental organizations to become involved as Official Observers. 5The International Arctic Sciences Committee (IASC) was founded 28 August 1990 

by national science organizations representing all of the arctic countries. It provides 

the major venue for national science organizations, mostly academies of science, to 

facilitate and foster cooperation in all fields of arctic research. IASC currently has 

participation by scientists from Canada, China, Denmark, Finland, France, Germany, Iceland, Italy, Japan, The Netherlands, Norway, Poland, Republic of Korea, 

Russia, Sweden, Switzerland, United Kingdom, and the United States. 6The IPCC’s assessments are all published by Cambridge University Press, and 

are also available over the Internet at http://www.ipcc.ch. IPCC’s Fourth Impact 

Assessment Report is due to be completed in 2007. 7 IPCC, 2001: Climate Change 2001: The Scientific Basis, edited by J. T. Houghton 

et al., Cambridge University Press, 881 pp., see also http://www.ipcc.ch. 8For example, see http://data.giss.nasa.gov/gistemp/2005/. Results of other centers give similar results. 9Such reconstructions estimate past values of surface temperature using treerings, coral growth patterns, changes in vegetation indicated by changes in pollen 

preserved in lake sediments, etc. 10For example, see Mann, M. E., and P. D. Jones, 2003: Global surface temperatures over the past two millennia. Geophysical Research Letters 30, 1820–1824, doi. 

10.1029/2003 GL017814. Controversies over the findings reported in this initial 

paper have largely been addressed over the years since it was published. 11See Attachment 1 for an overview by the authors of ACIA’s chapter on past climate change regarding the unprecedented patterns of modern warming and reconVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00071 Fmt 6633 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
68 

ciling this finding with the analyses of supposed similarly warm conditions in the 

early to mid-20th century. 12The near final draft of a tightly focused assessment by the U.S. Climate Change 

Science Program (see http://www.climatescience.gov/Library/sap/sap1-1/thirddraft/default.htm) of trends in surface and upper troposphere temperatures indicates that previous criticisms that warming rates have been significantly different 

are not valid. This focused assessment reports near resolution of this issue as a result of studies that have identified corrections needed in satellite and balloon 

records as a result of instrument and observational factors. 13These estimates allow for uncertainties in projections of future energy-related 

emissions. However, two other factors can also introduce uncertainties. First, 

present models have only a limited treatment of the processes that govern how rapidly CO2 will be taken up by the land and ocean carbon reservoirs; preliminary studies by Cox et al. (Cox, P.M., R.A. Betts, C.D. Jones, S.A. Spall, and I.J. Totterdell, 

2000: Acceleration of global warming due to carbon cycle feedbacks in a coupled climate model, Nature, 408, 184–187) and Fung et al. (Fung, I., S.C. Doney, K. Lindsay, and J. John, 2005: Evolution of carbon sinks in a changing climate, Proceedings 

of the National Academy of Sciences (USA), 102, 11201–11206, doi:10.1073/ 

pnas.0504949102) indicate that current models are overestimating the amount of 

carbon that can be taken up, thus leading to small underestimates of the rate of 

warming. Second, limits in our estimates of how the climate will respond to changing atmospheric composition are estimated to have the potential to increase or decrease the temperature changes in 2050 by about 0.3°C (roughly 0.5°F) and in 2100 

by about twice this amount, with the likelihood (as a result of recent studies of the 

likely effects of sulfate aerosols) that the change could be greater than estimated 

more likely than that these are overestimates. 14 ppmv stands for parts per million by volume, or number of CO2 molecules per 

million molecules of air. 15See Doney, S.C., 2006: The dangers of ocean acidification, Scientific American, 

294(3), March 2006, 58–65; and Ocean Acidification Due to Increasing Atmospheric 

Carbon Dioxide, Royal Society, 2005. Available at http://www.royalsoc.ac.uk/ 

displaypagedoc.asp?id=13314. 16See Kleypas, J. A., R. W. Buddemeier, D. Archer, J-P. Gattuso, C. Langdon, and 

B. N. Opdyke, 1999: Geochemical consequences of increased atmospheric carbon dioxide on coral reefs, Science, 284, 118–120; and Buddemeier, R. W., J. A. Kleypas, 

and R. B. Aronson, 2004: Coral reefs & global climate change: Potential contributions of climate change to stresses on coral reef ecosystems, Prepared for the Pew 

Center on Global Climate Change, http://www.pewclimate.org/global-warming-indepth/alllreports/corallreefs/index.cfm. 17See: Orr, J.C., V.J. Fabry, O. Aumont, L. Bopp, S.C. Doney, R.A. Feely, A. 

Gnanadesikan, N. Gruber, A. Ishida, F. Joos, R.M. Key, K. Lindsay, E. MaierReimer, R. Matear, P. Monfray, A. Mouchet, R.G. Najjar, G.-K. Plattner, K.B. Rodgers, C.L. Sabine, J.L. Sarmiento, R. Schlitzer, R.D. Slater, I.J. Totterdell, M.-F. 

Weirig, Y. Yamanaka, and A. Yool, 2005: Anthropogenic ocean acidification over the 

twenty-first century and its impact on marine calcifying organisms, Nature, 437, 

681–686, doi:10.1038/nature04095. 18Levitus, S., J. I. Antonov, and T. P. Boyer, 2005: Warming of the world ocean, 

1955–2003, Geophysical Research Letters, 32 (L02604), doi: 10.1029/2004GL021592. 

Levitus et al. find that over 90 percent of the energy trapped by the increasing concentrations of greenhouse gases ends up in the ocean. 19 Barnett, T. P., D. W. Pierce, K. M. AchutaRao, P. J. Gleckler, B. D. Santer, J. 

M. Gregory, and W. M. Washington, 2005: Penetration of human-induced warming 

into the world’s oceans, Science, 309, 284–287. 20For example, see Webster, P. J., G. J. Holland, J. A. Curry, and H.-R. Change, 

2005: Changes in tropical cyclone number, duration, and intensity in a warming environment, Science, 309, 1844–1846 and Emanuel, K. A., 2005: Increasing destructiveness of hurricane intensity on climate, Nature, 326, 483–485. 21 Anthes, R. A., R. W. Corell, G. Holland, J. W. Hurrell, M. C. MacCracken, and 

K. E. Trenberth, 2006: Hurricanes and Global Warming—Potential Linkages and 

Consequences, Bulletin of the American Meteorological Society, 87 (May, in press). 

With regard to the most important limitation in detection studies, it has been the 

presumption by a number of investigators (e.g., Pielke et al., 2005, Bulletin of the 

American Meteorological Society, 86, 1571–1575) that the response should be a linear trend in hurricane number (or in other factors) over the course of the century 

that is made dubious by many detection-attribution studies that indicate that 

human influences led to a time history of Northern Hemisphere temperature change 

during the 20th century consisting of warming early in the century, a slight cooling 

69 

in mid-century (especially in the North Atlantic sector that is key in affecting hurricane characteristics), and then a sharp warming since the 1970s. 22 Building societal resilience through adaptive efforts could include, in the shortterm, more effective evacuation, stronger levees, beach restoration, enhancing vegetation cover of dunes, strengthening of buildings, etc., and longer-term, withdrawal 

from the most vulnerable areas, enhanced building codes, storm surge barriers (e.g., 

being proposed to protect New York harbor), adding capacity to evacuation routes, 

etc. 23See for example: Sarmiento, J., R. Slater, R .Barber, L. Bopp, S.C. Doney, A.C. 

Hirst, J. Kleypas, R. Matear, U. Mikolajewicz, P. Monfray, V. Soldatov, S. Spall, R. 

Slater, and R. Stouffer, 2004: Response of ocean ecosystems to climate warming, 

Global Biogeochemical Cycles, 18, GB3003, doi:10.1029/2003GB002134. 24For example, see report in the Washington Post, April 15, 2006 entitled ‘‘Warming Arctic is Taking a Toll,’’ which reports on results of a scientific study appearing 

in the journal Aquatic Mammals that walrus calves are being found abandoned at 

sea (and almost certain to starve and drown) because there is no longer any sea ice 

for them to rest on in the areas shallow enough for their mothers to feed off the 

bottom. 25Policy Document is available at: www.acia.uaf.edu/PDFs/ACIAlPolicyl 

Document.pdf 26Karnosky, D. F., K. S. Pregitzer, D. R. Zak, M. E. Kubiske, G. R. Hendrey, D. 

Weinstein, M. Nosal, and K. E. Percy, 2005: Scaling ozone responses of forest trees 

to the ecosystem level in a changing climate, Plant, Cell, and Environment, 28, 965– 

981. 27 Reich, P. B., S. E. Hobbie, T. Lee, D. S. Ellsworth, J. B. West, D. Tilman, J. 

M. H. Knops, S. Naeem, and J. Trost, 2006: Nitrogen limitation constrains sustainability of ecosystem response to CO2, Nature, 440, 922–925. 28 Indeed, a number of studies suggest that, along with technology and seed enhancements, the increased CO2 concentration is already contributing to higher 

yields. 29 Note, however, that greater year-to-year variability or more frequently exceeding various temperature and/or moisture (or dryness) thresholds may make optimization to a narrow range of climatic variables more risky, and farmers may instead 

choose not to select seed strains that tolerate a wider range of conditions in exchange for slightly reduced productivity. A key determinant will be how rapidly improvements are made in the skill of seasonal forecasts, a topic on which research 

attention is being closely focused. 30 National Assessment Synthesis Team, 2001: Climate Change Impacts on the 

United States: The Potential Consequences of Climate Variability and Change: Foundation, U.S. Global Change Research Program, Cambridge University Press, 612 pp. 

Available at http://www.usgcrp.gov/usgcrp/nacc/default.htm. 31 Ibid. 32 Breshears, D. D., et al. 2005: Regional vegetation die-off in response to globalchange-type drought, Proceedings of the National Academy of Sciences, 102 (Oct. 18), 

15144–15148. Available at http://www.pnas.org/cgi/doi/10.1073/ 

pnas.0505734102. 33 Emanuel, K., 2005: Increasing destructiveness of tropical cyclones over the past 

30 years, Nature 436, 686–688. 34Friedlingstein, P., P. Cox, R. Betts, W. von Bloh, V. Brovkin, S. Doney, M. Eby, 

I. Fung, B. Govindasamy, J. John, C. Jones, F. Joos, M. Kawamiya, W. Knorr, K. 

Lindsay, H.D. Matthews, T. Raddatz, P. Rayner, C. Reick, E. Roeckner, K.-G. 

Schnitzler, R. Schnur, K. Strassmann, S. Thompson, A.J. Weaver, and N. Zeng, 

2006: Climate-carbon cycle feedback analysis; Results from the C4MIP model intercomparison, Journal of Climate, in press. 35See, for example, the Cox et al. and Fung et al. references provided above. 36For comparison, the CO2 increase from preindustrial to the present has been 

about 100 ppmv. 37 Beedlow, P.A., D.T. Tingey, D.L. Phillips, W.E. Hotsett, and D.M. Olszyk, 2004: 

Rising atmospheric CO2 and carbon sequestration in forests, Ecological Environment, 2, 315–322. 38Warmer lake temperatures also mean delayed formation of lake ice in the winter, perversely allowing a longer period for lake effects storms to dump snow on the 

surrounding regions. 39 Arctic peoples and the energy industry also depend on the frozen ground to enable moving around the Arctic; warming has already reduced by about half the 

number of days the ground is hard enough for movement of some oil-drilling equipment. 

70 

40See ‘‘Changes in the Velocity Structure of the Greenland Ice Sheet’’ by Eric 

Rignot and Pannir Kanagaratnam, Science Vol 311 17 February 2006, as well as 

‘‘The Greenland Ice Sheet and Global Sea-Level Rise by Julian A. Dowdeswell, 

Science Vol 311 17 February 2006, and also see Paterson, W.S.B., and N. Reeh, 

2001: Thinning of the ice sheet in northwest Greenland over the past forty years, 

Nature, 414, 60–62. 41 Note that throughout this process, the temperature of the ice surface when out 

on the banquet table would still be at the freezing point, even with an infrared lamp 

shining on it. What matters is the amount of heat being delivered while the temperature is fixed at the melting point—not that the temperature has not risen (as 

some Skeptics use as an argument to try to find fault with attributing the unprecedented melting back of glaciers to the unprecedented human-induced increase in 

greenhouse gas concentrations. 42See Gregory, J.M., P. Huybrechts, and S.C.B. Raper, 2004: Climatology: Threatened loss of the Greenland Ice Sheet, Nature, 428, 616; doi:10.1038/428616a. The 

IPCC’s Third Assessment Report suggests that the time scale for such melting 

would be millennia, but the recent identification of the meltwater runoff mechanism 

for more rapid melting is likely to lead to reductions in the estimates included in 

future assessments. 43That such melting occurred is evident by the absence of older ice in ice cores 

drilled in southern Greenland, but the presence of ice that old in cores drilled in 

northern Greenland. Beach horizons on remote islands that are located a few meters 

above present sea level appear to confirm that a comparable amount of water (or 

perhaps even more from some loss of the West Antarctic Ice Sheet) had been added 

to the oceans. See ‘‘Paleoclimatic Evidence for Future Ice-Sheet Instability and 

Rapid Sea-Level Rise’’ Jonathan T. Overpeck, Bette L. Otto-Bliesner, Gifford H. Miller, Daniel R. Muhs, Richard B. Alley, Jeffrey T. Kiehl Science 24 March 2006: Vol. 

311. no. 5768, pp. 1747–1750 DOI: 10.1126/science.1115159 44The very hot European summer of 2003 that led to a month-long heat wave 

that caused the premature deaths of tens of thousands is the type of rare event that 

is estimated to have become much more likely as a result of recent warming, and 

will become even more likely in the future (e.g., see Scha ̈ r, C. et al., 2004: The role 

of increasing temperature variability in European summer heat waves, Nature, 427, 

332–336.) 45Dai, A., K. E. Trenberth, and T. Qian, 2004: A global dataset of Palmer Drought 

Severity Index for 1870–2002: Relationship with soil moisture and effects of surface 

warming, Journal of Hydrometeorology, 5, 1117–1130. 46McKenzie, D., Z. Gedalof, D. L. Peterson, and P. Mote, 2004: Climatic change, 

wildfire, and conservation, Conservation Biology, 18, 890–902. 47Milly, P.C.D., R.T. Wetherald, K.A. Dunne, and T.L. Delworth, 2002: Increasing 

risk of great floods in a changing climate, Nature, 415, 514–17. 48 A large hurricane striking New Orleans is only one example of a very damaging 

event. Other examples identified during the U.S. National Assessment included a 

storm surge into New York harbor, and the entire northeast coastline that has been 

spared strong hurricanes for several decades has since become increasingly developed, and susceptible to very high damage events. 49See IPCC Working Group I Third Assessment Report, 2001. Over the past few 

decades, the rate of rise is consistent with a rate that exceeds the upper end of this 

range, indicating that an acceleration in the rate may have begun during this period 

(e.g., see Rignot, E., and P. Kanagaratnam, 2005: Changes in the velocity structure 

of the Greenland Ice Sheet, Science, 311, 986–990). 50The full range for the IPCC estimate is about 4 to 35 inches considering the 

full range of all emissions scenarios and climate sensitivities, whereas the central 

estimate used in the text is for the average response across all climate models and 

emissions scenarios. 51 Although projecting a rather significant buildup of ice on East Antarctica, 

IPCC’s Third Assessment Report projected only very limited melting of the Greenland and West Antarctic Ice Sheets over the 21st century. Observations since publication of that report suggest that at least the Greenland Ice Sheet is likely to experience significant loss of ice as the warming builds up over coming decades. 52Low levees have already been installed around LaGuardia airport due to a severe storm some 50 years ago, and many additional areas are at risk. Low lying 

islands in the Chesapeake Bay have also been lost over recent times, more due to 

natural land subsidence than human-induced sea level rise, but providing an insight 

into the likely consequences of an acceleration of the rate of rise due to global warming. And the severe loss of coastal wetlands in the Mississippi delta region (again 

due mainly to other factors up to the present) provides a telling example of how important the coastal islands are for protecting communities. 

71 

53GAO, 2004: Alaska Native Villages: Villages Affected by Flooding and Erosion 

Have Difficulty Qualifying for Federal Assistance, Statement of Robert A. Robinson, 

Managing Director, Natural Resources and Environment, GAO–04–895T. 54 It is substantially more difficult to catch a whale or seal by chasing it in open 

waters than by waiting for it to surface at an air hole. 55Pittock, A. B., 2005: Climate Change: Turning Up the Heat, Earthscan, London, 

316 pp. 56Parmesan, C., and G. Yohe, 2003: A globally coherent fingerprint of climate 

change impacts across natural systems, Nature, 421, 37–42. 57For example, see Cox, P.M., R.A. Betts, C.D. Jones, S.A. Spall, and I.J. 

Totterdell, 2000: Acceleration of global warming due to carbon cycle feedbacks in a 

coupled climate model, Nature, 408, 184–187. 58For example, see Watson, R.T., J. Patz, D.J. Gubler, E.A. Parson, and J. H. Vincent, 2005: Environmental health implications of global climate change, Journal of 

Environmental Monitoring, 7, 834–843, and Hunter, P. R., 2003: Climate change 

and waterborne and vector-borne disease, Journal of Applied Microbiology, 94, 37S– 

46S. 59 Beggs, P.J., and H.J. Bambrick, 2005: Is the global rise of asthma and early 

impact of anthropogenic climate change? Environmental Health Perspectives, 113, 

915–919. 60For a given level of pollution, higher temperatures accelerate the rate of formation of photochemical smog. 

Senator VITTER. Thank you very much, Doctor. 

And, Dr. Reiter, welcome. 

STATEMENT OF PAUL REITER, CHIEF, INSECTS AND 

INFECTIOUS DISEASE UNIT; PROFESSOR, INSTITUT PASTEUR 

Dr. REITER. Thank you, Senator Lautenberg, Senator Stevens, 

Mr. Chairman, Members of the Committee. 

I am a specialist in the natural history and biology of mosquitoes, the epidemiology of the diseases they transmit, and strategies 

for their control. I worked, for 22 years, for the Centers for Disease 

Control and Prevention, CDC, including 2 years as a research 

scholar at Harvard. I am a member of the World Health Organization Expert Advisory Committee on Vector Biology and Control. I 

have directed many entomological investigations of outbreaks of 

mosquito-borne disease and others, such as Ebola hemorrhagic 

fever. I was a lead author of the U.S. National Assessment of the 

Potential Consequences of Climate Variability and Change. I’m 

presently professor of medical entomology at the Institut Pasteur, 

in Paris, France. 

In this presentation, I restrict my comments to my own field, to 

malaria, and I will want to emphasize to you four points. First of 

all, that malaria is not an exclusively tropical disease. Second of 

all, the transmission dynamics of the disease are complex, and the 

interplay of climate, ecology, mosquito biology, mosquito behavior, 

and many other factors defies simplistic analysis. It is—third, it is 

facile to attribute the current resurgence of the disease to climate 

change or to use models based on temperature to predict future 

prevalence. And, last, many environmental activists are using the 

‘‘big talk’’ of science to create a simple, but very false, paradigm. 

Specialists, like myself, who protest this paradigm are generally ignored or are labeled ‘‘skeptics.’’ 

In the early 1990s, malaria topped the list of dangerous impacts 

of global warming. The disease was going to move to rich countries 

in the temperate regions as temperatures increased. This prediction ignored the fact that malaria was once an important cause 

of morbidity and mortality throughout most of the United States 

72 

and Europe, even in the period that our climatology colleagues 

have called the Little Ice Age. In the United States, as in Western 

Europe, despite a steadily warming climate, prevalence of malaria 

declined in the 19th century as a result of multiple changes in agriculture, lifestyle that affected the abundance of mosquitoes, their 

contact with people, and the availability of antimalarial drugs. 

Nevertheless, the most catastrophic epidemic of all time on record 

anywhere in the world occurred in the Soviet Union in the 1920s, 

with a peak incidence of 13 million cases per year and 600,000 

deaths. Transmission was high in many parts of Siberia, and there 

were 30,000 cases and 10,000 deaths in Archangel, close to the Arctic Circle. The disease persisted in many parts of Europe until the 

advent of DDT. Clearly here, temperature was not a limiting factor 

in the distribution or prevalence of malaria. 

In the mid-1990s, activist emphasis changed to the transmission 

of malaria in poorer countries, often referred to as ‘‘those least able 

to protect themselves,’’ particularly in sub-Saharan Africa. Yet in 

most of Africa, temperatures are already far above the minimum 

required for transmission. In addition, in most sub-Saharan Africa, 

transmission is termed ‘‘stable,’’ because people are already exposed to many infective bites, sometimes more than 300 per year. 

So, annual incidence is fairly constant. Mortality is highest in the 

newcomers, young children and immigrants. Those that survive acquire a partial immunity that reduces the risk of fatal illness. 

In other regions, transmission is endemic, but termed ‘‘unstable,’’ 

because annual transmission is variable. In these regions, the potential for epidemics is much higher, because immunity declines in 

periods of low transmission. Climatic factors, particularly rainfall, 

are sometimes, but by no means always, relevant. 

In recent years, activist emphasis has shifted to highland malaria, particularly in East Africa. Despite carefully research articles 

by malaria specialists, there has been a flurry of articles by nonspecialists who claim an increase in the altitude of malaria transmission that is already attributable to warming and quote models 

that predict further increase in the next 50 years. Tellingly, these 

people rarely, if ever, give any detail of the views of specialists who 

challenge them, nor do they mention that maximum altitudes for 

transmission in the period from 1880 until 1945 were 500 to 1,500 

meters higher than in the areas that are quoted as examples. And, 

in any case, highland above 2,000 meters constitutes a mere 1.3 

percent of the whole continent, an area about the size of Poland, 

totally dwarfed by regions of stable and unstable transmission at 

lower altitudes. 

An exasperating aspect of the debate is that this spurious science 

is endorsed in the public forum by influential panels of experts. I 

refer particularly to the Intergovernmental Panel on Climate 

Change. Every 5 years, this U.N.-based organization publishes a 

consensus of the world’s top scientists in all aspects of climate 

change. Quite apart from what we consider to be the rather dubious process by which these scientists are selected, consensus, sir, 

is the stuff of politics and not of science. Science proceeds by observation, hypothesis, and experiment. The complexity of this process 

and the uncertainties involved are a major obstacle to meaningful 

understanding of scientific issues by the lay public. In reality, a 

73 

genuine concern for mankind and the environment demands the inquiry, accuracy, and skepticism that are intrinsic to authentic 

science. A public that is unaware of this is vulnerable to abuse. 

The current increase in malaria is alarming, but the principal 

factors involved are deforestation, new agricultural practices, population increase, urbanization, poverty, civil conflict, war, AIDS, resistance to antimalarials, and resistance to insecticides. In my 

opinion, we should give priority to a creative and organized effort 

to stem the burgeoning tragedy of uncontrolled malaria, rather 

than worrying about the weather. 

Thank you for the honor of having spoken here. 

[The prepared statement of Dr. Reiter follows:] 

PREPARED STATEMENT OF PAUL REITER, CHIEF, INSECTS

AND INFECTIOUS DISEASE UNIT; PROFESSOR, INSTITUT PASTEUR

Malaria in the Debate on Climate Change and Mosquito-borne Disease 

I am a specialist in the natural history and biology of mosquitoes, the epidemiology of the diseases they transmit, and strategies for their control. I worked for 22 

years for the Centers for Disease Control and Prevention (CDC), including 2 years 

as a Research Scholar at Harvard. I am a member of the World Health Organization 

Expert Advisory Committee on Vector Biology and Control. I have directed many 

investigations of outbreaks of mosquito-borne disease, and of others such as Ebola 

Haemorrhagic Fever. I was a Lead Author of the U.S. National Assessment of the 

Potential Consequences of Climate Variability and Change. I am presently Professor 

of Medical Entomology at the Institut Pasteur in Paris, France. 

In this brief presentation I restrict my comments to malaria, and emphasize four 

points: 

1. Malaria is not an exclusively tropical disease. 

2. The transmission dynamics of the disease are complex; the interplay of climate, ecology, mosquito biology, mosquito behavior and many other factors defies simplistic analysis. 

3. It is facile to attribute current resurgence of the disease to climate change, 

or to use models based on temperature to ‘‘predict’’ future prevalence. 

4. Environmental activists use the ‘‘big talk’’ of science to create a simple but 

false paradigm. Malaria specialists who protest this are generally ignored, or 

labelled as ‘‘sceptics.’’ 

In the early 1990s, malaria topped the list of dangerous impacts of global warming; the disease would move to temperate regions as temperatures increased. This 

prediction ignored the fact that malaria was once an important cause of morbidity 

and mortality throughout most of the U.S. and Europe, even in a period that climatologists call the ‘‘Little Ice Age.’’ In the US, as in western Europe, prevalence 

declined in the 19th century as a result of multiple changes in agriculture and lifestyle that affected the abundance of mosquitoes, their contact with people, and the 

availability of anti-malarial drugs. Nevertheless, the most catastrophic epidemic on 

record anywhere in the world occurred in the Soviet Union in the 1920s, with a 

peak incidence of 13 million cases per year, and 600,000 deaths. Transmission was 

high in many parts of Siberia, and there were 30,000 cases and 10,000 deaths in 

Archangel, close to the Arctic circle. The disease persisted in many parts of Europe 

until the advent of DDT. Clearly, temperature was not a limiting factor in its distribution or prevalence. 

In the mid-1990s, activist emphasis changed to transmission in poorer countries, 

often referred to as those ‘‘least able to protect themselves,’’ particularly in sub-Saharan Africa. Yet in most of the continent, temperatures are far above the minimum 

required for transmission, and most of sub-Saharan Africa, transmission is termed 

‘‘stable’’ because people are exposed to many infective bites, sometimes more than 

300 per year, so annual incidence is fairly constant. Mortality is highest in ‘‘newcomers’’—young children and immigrants. Those that survive acquire a partial immunity that reduces the risk of fatal illness. In other regions, transmission is endemic but ‘unstable’ because annual transmission is variable; the potential for 

epidemics is great because immunity declines in periods of low transmission. Climatic factors, particularly rainfall, are sometimes—but by no means always—relevant. 

74 

In recent years, activist emphasis has shifted to ‘‘highland malaria,’’ particularly 

in East Africa. Despite carefully researched articles by malaria specialists, there has 

been a flurry of articles by non-specialists who claim a recent increase in the altitude of malaria transmission attributable to warming, and quote models that ‘‘predict’’ further increase in the next 50 years. Tellingly, they rarely quote the specialists who challenge them. Nor do they mention that maximum altitudes for transmission in the period 1880–1945 were 500–1500m higher than in the areas that are 

quoted as examples. Moreover, highland above 2000m constitutes a mere 1.3 percent 

of the whole continent, an area about the size of Poland that is totally dwarfed by 

regions of stable and unstable transmission at lower altitudes. 

A galling aspect of the debate is that this spurious ‘‘science’’ is endorsed in the 

public forum by influential panels of ‘‘experts.’’ I refer particularly to the Intergovernmental Panel on Climate Change (IPCC). Every 5 years, this UN-based organization publishes a ‘consensus of the world’s top scientists’ on all aspects of climate 

change. Quite apart from the dubious process by which these scientists are selected, 

such consensus is the stuff of politics, not of science. Science proceeds by observation, hypothesis and experiment. The complexity of this process, and the uncertainties involved, are a major obstacle to meaningful understanding of scientific issues 

by non-scientists. In reality, a genuine concern for mankind and the environment 

demands the inquiry, accuracy and skepticism that are intrinsic to authentic 

science. A public that is unaware of this is vulnerable to abuse. 

The current increase in malaria is alarming, but the principal factors involved are 

deforestation, new agricultural practices, population increase, urbanization, poverty, 

civil conflict, war, AIDS, resistance to anti-malarials, and resistance to insecticides, 

not climate. In my opinion, we should give priority to a creative and organized effort 

to stem the burgeoning tragedy of uncontrolled malaria, rather than worrying about 

the weather. 

The Lancet Infectious Diseases, Vol. 4, June 2004 

REFLECTION & REACTION—GLOBAL WARMING AND MALARIA: A CALL FOR ACCURACY

For more than a decade, malaria has held a prominent place in speculations on 

the impacts of global climate change. Mathematical models that ‘‘predict’’ increases 

in the geographic distribution of malaria vectors and the prevalence of the disease 

have received wide publicity. Efforts to put the issue into perspective 1– 5 are rarely 

quoted and have had little influence on the political debate. The model proposed by 

Frank C Tanser and colleagues 6 in The Lancet and the accompanying Commentary 

by Simon Hales and Alistair Woodward 7 are typical examples. 

The relation between climate and malaria transmission is complex and varies according to location,2 yet Tanser et al base their projections on thresholds derived 

from a mere 15 African locations. Slight adjustments of values assigned to such 

thresholds and rules can influence spatial predictions strongly.8 The authors invest 

considerable effort in assessments of the sensitivity of their model, at the expense 

of defining the internal sensitivities of their thresholds and rules. The predictive 

skill of their model is low (63 percent sensitivity, 95 percent CI 61–65 percent) but 

they consider projections acceptable if prevalence is projected ‘‘to within a month’’ 

(presumably +/¥ 1 month?), thereby biasing their model toward success. A model 

covering an entire year in a parasite-positive site would always be correct, although 

in such areas it would be relatively insensitive to climate. By contrast, sites in 

which transmission is seasonal would provide a more reliable test of accuracy, but 

estimation is more difficult because climate sensitivity is greater. Furthermore, because parasite clearance in communities is not instantaneous,9 spot samples of 

parasitaemia on survey dates are not a suitable indicator of the duration of the 

transmission season. Last, ‘‘person/months’’ are unsuitable as a measure of transmission: an extension of season from 1 to 4 months will have more impact than from 

10 to 12 months. According to their model, an extension of transmission from 11 

to 12 months results in 10 6 more person/months in a population of 10 6 people, 

whereas an extension from 1 to 5 months gives the same increase in a population 

of 250,000. 

What Tanser and colleagues have modelled is merely the duration of the transmission season, which they interpret as ‘‘heightened transmission’’ and increased incidence. A greater failing is their reliance on ‘‘parasiteratio studies.’’ The relations 

between transmission season and parasite prevalence, and parasite prevalence and 

clinical disease, are unclear but unlikely to be linear. Moreover, they use 1995 data 

for human populations, although these are projected to double by 2030. In addition, 

the proportion living in urban areas—with a specific climate 10 and orders of magnitude less malaria transmission 11, 12—is projected to rise from 37 percent to 53 

75 

percent.13 For all these reasons, we do not accept the model as a ‘‘baseline against 

which interventions can be planned.’’ 

It is regrettable that many involved in this debate ignore the rich heritage of literature on the subject. For example, in 1937, in his classic textbook,14 L W Hackett 

stated: ‘‘Everything about malaria is so moulded and altered by local conditions that 

it becomes a thousand different diseases and epidemiological puzzles. Like chess, it 

is played with a few pieces, but is capable of an infinite variety of situations.’’ A 

pressing question in Hackett’s time was the changing distribution of the disease in 

Europe. On the role of climate, he wrote: ‘‘Certainly, climate lays down the broad 

lines of malaria distribution . . . Nevertheless, although this is a very simple and 

plausible explanation . . . even the early malariologists (sic) felt that there was 

something unsatisfactory about it . . . malaria has not so much receded as it has 

contracted, oftentimes toward the north . . . Thus in Germany it is the northern 

coast which is still malarious, the south is free . . . There is, therefore, no climatic 

reason why (malaria) should have abandoned south Germany or the French Riviera.’’ 

We quote Hackett because we feel that the classic components of science—unbiased observation and systematic experimentation—cannot be sidestepped with models that omit many of his chess pieces. Yet Hales and Woodward 7 begin by stating: 

‘‘The present geographical distribution of malaria is explained by a combination of 

environmental factors (especially climate) and social factors (such as disease-control 

measures).’’ In our opinion, ‘‘even the early malariologists’’ would surely disagree: 

much of the decline of malaria in Europe took place without control measures during a period when the climate was warming. 

The text by Hales and Woodward that follows displays a lack of knowledge. Thus, 

‘‘Most people at risk of malaria live in areas of stable transmission . . . ’’ is simply 

wrong. It is true that in many parts of the world malaria is termed ‘‘stable’’ because 

transmission remains relatively constant from year to year, the disease is endemic, 

the collective immunity is high, and epidemics are uncommon. However, in many 

other regions, the disease is endemic but ‘‘unstable’’ because annual transmission 

varies considerably, and the potential for epidemics is great. Climatic factors, particularly rainfall, are sometimes, but by no means always, relevant.15

Again, ‘‘On the fringes of endemic zones, where transmission is limited by rainfall 

. . . there are strong seasonal patterns, and occasional major epidemics’’ is also 

wrong. In many regions, far from any ‘‘fringes,’’ malaria is endemic, stable, but highly seasonal. For example, in semi-arid regions of Mali, transmission is restricted to 

the rainy season, from July to September. The same 3 months constituted the transmission season for Plasmodium falciparum in Italy before it was eliminated.16 Paradoxically, in parts of the Sudan, rainfall is restricted to a month at most, but malaria is transmitted throughout the year. Female Anopheles gambiae survive severe 

drought and extreme heat by resting in dwellings and other sheltered places.17

Blood feeding and transmission continue, but the mosquitoes do not develop eggs 

until the rains return. This phenomenon, termed gonotrophic dissociation, is remarkably similar to the winter survival strategy of Anopheles atroparvus, the principal vector of malaria in Holland until the mid 20th century.16

By contrast, malaria is unstable in many regions that normally have abundant 

rainfall, and epidemics occur during periods of drought. An illustrative example is 

the catastrophic 1934–1935 epidemic in Ceylon (now Sri Lanka), estimated to have 

killed 100,000 people.18 Worst hit was the southwestern quadrant of the country, 

where average annual rainfall is greater than 250 cm, and malaria was endemic, 

but unstable and relatively infrequent. The dominant vector, Anopheles culicifacies, 

breeds along the banks of rivers and tends to be scarce in normal years. In the years 

1928–1933 there was abundant rainfall, river flow was high, An culicifacies was 

rare, and the human population was exceptionally malariafree. However, after failure of two successive monsoons, the drying rivers produced colossal numbers of An 

culicifacies, and the resulting epidemic was exacerbated by the low collective immunity. In the drier parts of the island, where An culicifacies was dominant but transmission was more stable, immunity protected the population from the worst ravages 

of the disease. 

Hales and Woodward state that ‘‘the underlying problem’’ of the future ‘‘extension 

of seasonality’’ of malaria is ‘‘pollution of the atmosphere’’, and call for rich countries 

to ‘‘recognise their obligations to the poorest by substantially reducing fossil-fuel 

consumption.’’ We understand public anxiety about climate change, but are concerned that many of these muchpublicised predictions are ill informed and misleading. We urge those involved to pay closer attention to the complexities of this 

challenging subject. 

76 

Paul Reiter, Christopher J Thomas, Peter M Atkinson, Simon I Hay, Sarah E 

Randolph, David J Rogers, G Dennis Shanks, Robert W Snow, and Andrew J 

Spielman. 

PR is professor of medical entomology, Institut Pasteur, Paris, France; CJT is 

senior lecturer in spatial ecology and Wolfson Institute fellow in health and environment, School of Biological and Biomedical Sciences, University of Durham, 

UK; PA is professor of geography, University of Southampton, UK; SIH is a 

Wellcome Trust research fellow, SER is professor of parasite ecology, and DJR 

is professor of ecology, Department of Zoology, University of Oxford, UK; GDS 

is at the U.S. Army Centre for Health Promotion and Preventive Medicine, MD, 

USA; RWS is professor of tropical public health, University of Oxford; AJS is 

professor of tropical public health, immunology and infectious diseases, Harvard 

School of Public Health, Boston, MA, USA. SIH and RWS are also at the 

KEMRI Wellcome Trust collaborative programme, Kenya. 

References 1 Reiter P. From Shakespeare to Defoe: malaria in England in the little ice age. 

Emerg Infect Dis 2000; 6: 1–11. 2 Reiter P. Climate change and mosquito-borne disease. Environ Health Perspect 

2001; 109 (suppl 1):141–61. 3 Hay SI, Cox J, Rogers DJ, et al. Climate change and the resurgence of malaria 

in the East African highlands. Nature 2002; 415: 905–09. 4Shanks GD, Hay SI, Stern DI, Biomndo K, Snow RW. Meteorologic influences 

on Plasmodium falciparum malaria in the highland tea estates of Kericho, Western 

Kenya. Emerg Infect Dis 2002; 8: 1404–08. 5 Rogers DJ, Randolph SE. The global spread of malaria in a future, warmer 

world. Science 2000; 289: 1763–66. 6Tanser FC, Sharp B, le Sueur D. Potential effect of climate change on malaria 

transmission in Africa. Lancet 2003; 362: 1792–98. 7 Hales S, Woodward A. Climate change will increase demands on malaria control 

in Africa. Lancet 2003; 362: 1775. 8Thomas CJ, Davies G, Dunn CE. Mixed picture for changes in stable malaria 

distribution with future climate in Africa. Trends Parasitol 2004; 20: 216–20. 9Smith T, Charlwood JD, Kihonda J, et al. Absence of seasonal variation in malaria parasitaemia in an area of intense seasonal transmission. Acta Trop 1993; 54: 

55–72. 10 Arnfield A. Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island. Int J Climatol. 2003; 23: 

1–26. 11Snow R, Trape J, Marsh K. The past, present and future of childhood malaria 

mortality in Africa. Trends Parasitol 2001; 17: 593–97. 12 Robert V, Macintyre K, Keating J, et al. Malaria transmission in urban subSaharan Africa. Am J Trop Med Hyg 2003; 68: 169–76. 13 United Nations. World urbanization prospects: the 2001 revision. Data tables 

and highlights. New York: United Nations, 2002. 14 Hackett LW. Malaria in Europe, an ecological study. London: Oxford University 

Press, 1937. 15Gilles HM, Warrell DA, eds. Bruce-Chwatt’s essential malariology. London: Edward Arnold, 1993. 16 Bruce-Chwatt LJ, de Zulueta J. The rise and fall of malaria in Europe, a 

historico-epidemiological study. Oxford: Oxford University, 1980. 17Omer SM, Cloudsley-Thompson JL. Survival of female Anopheles gambiae Giles 

through a 9-month dry season in Sudan. Bull World Health Organ 1970; 42: 319– 

30. 18Dunn C. Malaria in Ceylon: an enquiry into its causes. London: Bailliere, 

Tindall and Cox, 1937. 

Other Attachments 

These articles are in committee files and can be found at their respective 

websites: 

Climate Change and Mosquito-Borne Disease, Paul Reiter, Environmental 

Health Perspectives, Vol. 109, Supplement 1: Reviews in Environmental Health, 

2001 (Mar., 2001), pp. 141–161. 

http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1240549&blobtype=pdf. 

From Shakespeare to Defoe: Malaria in England in the Little Ice Age, Paul 

Reiter 

77 

Emerging Infectious Diseases, Vol. 6, No. 1, January–February 2000 

http://www.cdc.gov/ncidod/eid/vol6no1/reiter.htm 

Senator VITTER. Thank you very, very much, Doctor. I’ll kick off 

the questioning. 

Dr. Corell—— 

Dr. CORELL. Yes. 

Senator VITTER.—I wonder if you could put up one of your first 

slides, which was the temperature chart, because I’m trying to understand it, in part, by—— 

Dr. CORELL. Sure. 

Senator VITTER.—comparing it to Dr. Armstrong’s figure 1. Are 

you familiar with Dr. Armstrong’s—— 

Dr. CORELL. I am not—— 

Senator VITTER.—slide? 

Dr. CORELL.—but I’d be happy to have a look at it. Yes, OK. I 

now know what—— 

Senator VITTER. Right. Your—— 

Dr. CORELL. This—— 

Senator VITTER.—chart basically goes back to—— 

Dr. CORELL. This is 2,000 years. 

Senator VITTER.—2,000 years. Dr. Armstrong’s figure 1 is much 

more long term, I think. 

Dr. CORELL. That’s correct. 

Senator VITTER. It goes back 400,000 years. 

Dr. CORELL. Right. 

Senator VITTER. And so, I guess the comparison—the conclusion 

from the comparison is—and correct me if I’m wrong—that the 

Earth has experienced similar temperature levels to the present 

day, but much further back than 2,000 years. 

Dr. CORELL. That’s correct. And I would say it’s the CO2 that is 

way above the record, certainly in the record that’s in his testimony, but there are several papers that suggest that we have not 

had these CO2 levels for 25 million years. 

Senator VITTER. Right. And his chart also suggests that, because 

if—— 

Dr. CORELL. Right. 

Senator VITTER.—you’re looking at it—— 

Dr. CORELL. That’s—— 

Senator VITTER.—his chart of CO2 and CH4, they’re—— 

Dr. CORELL. Are well—— 

Senator VITTER.—way beyond—— 

Dr. CORELL.—well beyond the—— 

Senator VITTER.—anything in the last 400,000 years. And 

that—— 

Dr. CORELL. And—— 

Senator VITTER.—provoked my question—— 

Dr. CORELL. Yes, about—— 

Senator VITTER.—which is—— 

Dr. CORELL.—the lead-lag issue. 

Senator VITTER. Right. 

Dr. CORELL. Let me say a word or two about it and go to another 

slide here, if I can, and that’s this one. As this imbalance of heat 

comes into the system, and the ocean observe it—absorbs it, it’s 

78 

going to re-radiate that and heat—and reheat the atmosphere. But 

this out-of-balance is due to the CO2 level being much higher, creating the greenhouse effect. And so, there’s—during a time when 

we have both natural variability and human-induced variability, or 

human-induced warming, during that time the temperature is 

going to lag behind the rise in CO2. Do you follow that, from 

this—— 

Senator VITTER. Now, why is that different from a period where 

it’s a purely natural process? 

Dr. CORELL. Because—well, several reasons. One, there’s a much 

slower rate of warming occurring in—during the natural process 

period. And, quite frankly, if you look at this 400,000-year record, 

it’s pretty hard to sort out the lead-lag relationship. In fact, some 

will argue that it—sometimes temperature leads the CO2 and other 

times it lags the CO2, and that’s probably due to a bunch of—a 

whole group of natural processes. A lot of them are the wobbling 

and the precessions of the planet and so on. But what I want to 

make—the difference is that we are in a region now where we have 

clearly natural variability, and, on top of that, we have the humaninduced increase in CO2, and that human-induced in CO2 is likely 

to cause the temperature to lag behind the CO2 rise. 

So, the answer to your question, in my judgment, is that we are 

going to see a continued rise in temperature. Most recent meeting 

in the U.K. held by John Shellnhuber and the group on the dangerous intervention issue, concluded that as we sit here, we’re likely to see 2 to 3 degrees of warming, Centigrade, during this coming 

century. So, whether—we definitely will have a rise in temperature, given the rate at which CO2 is increasing today. 

Senator VITTER. Dr. Akasofu, do you have any reaction or comment? 

Dr. AKASOFU. No, on this particular point, because as Dr. Corell 

mentioned, all the changes are going on. Climate change is going 

on, definite. No question about that. And the only thing we are trying to find is which portion is natural, which is manmade. 

Senator VITTER. Right. 

Dr. AKASOFU. From our study, we—the—we cannot tell. 

Senator VITTER. Right. 

I want to go to Dr. Akasofu’s figure 1, which is really interesting 

to me. His basic explanation of the dip in both Arctic and the 

smaller dip in global temperature between 1940 and 1970 is that 

you have major natural factors, as well as manmade. What would 

be your explanation, Dr. Corell? 

Dr. CORELL. Well, I think there are times when a—the—in this 

early part of the rise in temperature, where the natural variability 

can override. And we will see—I think the general consensus of the 

literature is that that relative cooling—relative cooling that occurred in—as Dr. Akasofu has pointed out—has—was due to a natural variability factor. But now I think we can see from the record, 

certainly in the last half a century, that the IPCC and much of the 

literature will indicate that the predominant factor of the warming 

is coming from human-induced CO2 contributions to the atmosphere. 

Senator VITTER. How do they reach that conclusion? How do they 

parcel out natural versus human? 

79 

Dr. CORELL. Well, one way to do it—there are several—one is to 

take your models—and I would like to talk a little about the models, because you asked a very good question about that—and ask 

yourself, How could we get the temperature that we have today? 

And we have a pretty good idea of solar variability over the last 

50 to 100 years. We have a clear idea of what volcanic eruptions 

are. Those are—you know, those are cooling effects. In other words, 

we have a pretty good idea of the major contributing factors. If you 

try to get the temperature that we have today without the humaninduced factor, you just can’t get there. And there have been numerous papers that do this. 

Now, we’re talking at the global scale. And I think—— 

Senator VITTER. May I interrupt for a second? 

Dr. CORELL. Yes. 

Senator VITTER. Why can’t you get there, since, historically, 

Earth has been there? 

Dr. CORELL. Well, the conditions of the past at which it got there 

were quite different than the ones we have today. I mean, there are 

times when we’ve had much warmer regions of the Arctic there. 

You know, we had mastodons running around in a much warmer— 

a much warmer set of conditions. 

What we’re talking about here is, What’s changing the conditions 

now, over the last, well, let’s say 2 and a half million years, when 

we have had the glaciation periods with all these cycles occurring? 

During that time, we could not get to the temperatures we’ve gotten today—I mean, the CO2 and temperatures we’ve got today— 

without having CO2 being put into the atmosphere by humans. 

Senator VITTER. Well, again, doesn’t Dr. Armstrong’s figure 1 

suggest otherwise with regard to temperature, not CO2? 

Dr. CORELL. Well, he’s not only talking about—Dr. Armstrong’s— 

yes. Try me again. I was thinking of Dr. Akasofu’s question. 

Senator VITTER. No, no, that other figure—— 

Dr. CORELL. Oh, I—— 

Senator VITTER.—the one—— 

Dr. CORELL.—I know which one you’re talking—I just misunderstood—— 

Senator VITTER. Doesn’t that—— 

Dr. CORELL.—your question. 

Senator VITTER.—suggest, contrary to what you just said, that 

you can’t get there otherwise with regard to temperature, not—I 

mean CO2 levels, clearly—— 

Dr. CORELL. CO2, methane—— 

Senator VITTER.—all-time high—— 

Dr. CORELL. Right. 

Senator VITTER.—nothing. But temperature level is not, at least 

yet. 

Dr. CORELL. At this stage, we’re at about the level—the maximum levels we’ve seen during the glacial period of the last million 

or 2 million years, that’s correct. But what I’m suggesting is that 

we already know there’s more temperature buried in the ocean to 

come out from CO2 already put in the atmosphere by humans during the past 10, 20, 30 years, so that the future—— 

Senator VITTER. Well, but that is—— 

Dr. CORELL.—will be warm. 

80 

Senator VITTER.—that conclusion assumes that CO2 is driving— 

the single factor or predictor. 

Dr. CORELL. Well, I think the physics on that is pretty clear, that 

CO2 and the greenhouse gases do trap the energy between the 

upper atmosphere and the ground, and warm the planet. I think 

that’s—the physics on that’s clear. 

I’m maybe not getting your point, sir. 

Senator VITTER. Well, again, it seems to me, in terms of the historical record, you’re sort of assuming that CO2 is the perfect predictor and overrides anything else. 

Dr. CORELL. Well, I think if you do the physics on CO2 and the 

other greenhouse gases, they will trap the energy between the 

upper atmosphere and the ground, and will warm the planet. And 

what is clear to us now is, the ocean has enough information— 

enough heat in it to warm the planet beyond anyplace we have 

been over the last, say, 400,000 years. 

Senator VITTER. Dr. Akasofu, obviously the Arctic is an extreme 

case compared—— 

Dr. AKASOFU. Yes. 

Senator VITTER.—to global situations. 

Dr. AKASOFU. That’s correct. 

Senator VITTER. Now, that could suggest that it’s the perfect 

place to study, because it is—shows a heightened level of trends 

that are global, or it—maybe it could suggest the opposite, that it’s 

sort of an anomaly. What’s your conclusion about that basic question? 

Dr. AKASOFU. It goes—the Antarctic, as you said, is an signal 

magnitude or amplitude is at least three times bigger. So, so much 

easier to study. And, furthermore, what really—in this latitude, 

you don’t see .6 degree temperature change what’s happening, but 

Arctic, you can see all kinds of—— 

Senator VITTER. Right. 

Dr. AKASOFU.—climatic—climate changes going on. So, the Arctic 

is, to me, the place we should study. That’s—there is no disagreement with—— 

Dr. CORELL. No, no—— 

Dr. AKASOFU.—Dr. Bob Corell, yes. But the—Dr. Corell says yes, 

physics of the CO2 is greenhouse gas. Our question is, quantitatively, how many degrees, and where? And the observations 

show that the actual largest, most prominent warming taking— 

that was taking place in the continental Arctic. But somehow the 

IPCC computer could not produce that. And that means, to me, it’s 

something else. And we found that it is something else, not the 

greenhouse effect. So, we have to be very careful here. 

Senator VITTER. I’m glad you mentioned that, because it goes 

back to some of the testimony from the first panel, where they suggested that some of the very recent work, including a publication 

in Nature very recently, fine-tuned some of the climatic models in 

such a way that it was very predictive, looking back to what we 

have measured historically. Can you react to that? 

Dr. AKASOFU. Sorry, I don’t think so at this time. I—our interest 

is try to understand the increase from 1920 to 1940—— 

Senator VITTER. Right. 

81 

Dr. AKASOFU.—and then the decrease from 1940 to 1970. Unless 

we understand that, we don’t think we understand the increase 

from 1970 on. 

Senator VITTER. Right. 

Dr. AKASOFU. Yes. 

Senator VITTER. Let me ask it a different way. How good and 

perfected do you think the current climatic models are, in terms of 

temperature prediction, if you test it against that bit of history? 

Dr. AKASOFU. I believe that there are all kinds of complexities 

there, but the general pattern, to me, that computers should be 

able to produce—I mean, we have advanced so much in our simulators, all kinds of a major supercomputers working, so I trust that, 

at least, you know, some aspects should be—you know, computer 

should reproduce. And if the computers cannot reproduce—and, 

you know, that was the basis for the Kyoto Protocol. 

Senator VITTER. Right. 

Dr. AKASOFU. And if you say the computers are no good, then we 

have to abandon the Kyoto Protocol, too. So,—— 

Senator VITTER. Right. 

Chairman Stevens? 

The CHAIRMAN. Thank you. 

Dr. Akasofu, at your request we authorized funding for further 

temperature measurements in the Arctic Ocean over the—what, 

the last 3 years? How many years? 

Dr. AKASOFU. Yes. 

The CHAIRMAN. And there—have you had any tentative conclusions from those temperatures as to whether there is noticeable 

change now, as far as the temperature of the Arctic Ocean? 

Dr. AKASOFU. Yes. The—what’s happening is that the warm 

North Atlantic water is intruding into the Arctic Ocean, and we are 

tracing this water. It’s moving around Siberian coast, and then 

moving toward Alaska. So, although it’s a very complicated thing, 

but suddenly tremendous heat is coming from the North Atlantic 

into the Arctic Ocean, which is, I’m sure, the partial reason for the 

ice melting there. 

The CHAIRMAN. And is that in any way related to the recent intensity of the sun’s heat, as far as the Atlantic Ocean is concerned? 

Dr. AKASOFU. That, I can’t tell. We just learned that—in the last 

paper, that as much as 30 to 40 percent of temperature increase 

could have been due to just the solar output increase. But we have 

to now go back and look at the computer modeling and put it in 

that and see if that will warm up North Atlantic or not. We have 

not done that yet. 

The CHAIRMAN. And this—we have your statement, and figure 6 

showing the distribution of that Atlantic water, the so-called Atlantic oscillation. How long has that been going on, do you know? 

Dr. AKASOFU. Oh, as far as we determine, you know, it’s at least 

50—accurately, the last 50–60 years over good data—what we call 

NAO, North Atlantic oscillation, intensity changes, and we know 

that. 

The CHAIRMAN. Well, is that warming of the Arctic Ocean related 

to some of the change we see in our State now, as far as the permafrost and basic change in the climate? 

82 

Dr. AKASOFU. OK, that’s—our scientists have—different scientists have a different point of view. The continental portion of 

warming, they think that could be something else. But the—they 

are not sure yet. 

The CHAIRMAN. By that, you mean what’s happening in the Arctic Ocean could be both natural and manmade. 

Dr. AKASOFU. I think so. 

The CHAIRMAN. How long a period do we have to study that to 

reach a—any tentative conclusion on it? 

Dr. AKASOFU. The—in the past—I think—this is my view—that 

people are aware that the—there are natural and manmade, both 

components, but not many people really spent the time to separate 

those out. It’s very difficult. Whenever there is—we should make 

the effort. And we are now concentrating—some of us really working hard to do that particular job, rather than study with just the 

North Atlantic water coming in or something else. 

The CHAIRMAN. Have you flown over the Arctic area recently? 

Dr. AKASOFU. Not recently, not last year or so. 

The CHAIRMAN. I took one flight—this’ll be my last comment— 

over—coming from the West Coast, going over to Barrow, and it 

was pointed out to me the places where the ocean had been up far 

inland from where it is now. And the pilot indicated that it showed 

that while we think the water is rising now, it hasn’t come up near 

where it was in years—many years gone by. 

Dr. AKASOFU. Yes. 

The CHAIRMAN. Now, are you able to study those other areas and 

see what the fluctuation has been, in terms of the Arctic Ocean’s 

intrusion upon the Alaska part of our continent? 

Dr. AKASOFU. Some of us are studying the ocean conditions or 

land—the features from the last Ice Age, not before that. But I 

think our people are collecting lots of data from during the last age, 

can see the major changes. And also even during a little ice age we 

had from 1300 to 1800, some major changes in terms of glaciers advance and retreat. 

The CHAIRMAN. I don’t know if my colleagues had a chance to 

read the statement you’ve got—that you’ve submitted, but very 

clearly I take it that the impact that you’re trying to leave with us, 

is, we don’t know enough yet to make a judgment as to what part 

of this is manmade and what part is natural. 

Dr. AKASOFU. I think I agree with Dr. Armstrong. We are trying, 

trying. This is very hard. And perhaps IPY, International Polar 

Year, when some scientists concentrate on this, we may make good 

progress. 

The CHAIRMAN. Thank you very much. 

Senator VITTER. Thank you. 

Senator Lautenberg? 

The CHAIRMAN. I want to thank the others, too, also, but I have 

to go to a meeting. I don’t want to prolong this right now. 

Senator LAUTENBERG. Mr. Chairman, I’m a little confused here 

with something—some of the things that are said. And I ask Dr. 

Akasofu, Are you aware of any peer-reviewed science study that’s 

said—or asserted that the present warming in the Arctic or globally is entirely due to human-caused global warming? 

83 

Dr. AKASOFU. It’s—I believe that is more of the press takes that 

view, but most scientists agree that there are two components, 

those manmade—— 

Senator LAUTENBERG. I understand that, sir. I just want to be 

sure, because as I read your paper I had the—I drew the understanding that you ascribe most of this to human-caused global 

warming, and that the natural phenomena, the natural changes 

that are caused, are not something to be as concerned about. And 

now you do say there’s a division, that there—it—the—both areas 

result in these changes that we’re seeing. The changes are obvious. 

You’ve confirmed that in your—— 

Dr. AKASOFU. Yes. 

Senator LAUTENBERG.—statement. 

Dr. AKASOFU. Right. No question. 

Senator LAUTENBERG. Yes. 

Dr. AKASOFU. Yes. Dr. Corell described it beautifully, those 

changes. 

Senator LAUTENBERG. Yes. 

Dr. AKASOFU. The question is, How much is due to—— 

Senator LAUTENBERG. Yes. How much, Dr. Akasofu, would you— 

do you think that we ought to get after those things that we identify as caused by human existence, CO2? Is that largely caused by 

human activities, or is that—is there any of that, that comes from 

natural—— 

Dr. AKASOFU. OK. In science—in scientific methodologies, we assume, say, it is due to carbon dioxide, and then the—we use a 

supercomputer—supercomputer behave like virtual Earth. We put 

in CO2 into, and then calculate the result. 

Senator LAUTENBERG. Yes. 

Dr. AKASOFU. And if the results agree with the observations, 

then that is the way to confirm that—— 

Senator LAUTENBERG. Yes, I—— 

Dr. AKASOFU.—it’s CO2. 

Senator LAUTENBERG. Forgive me for—— 

Dr. AKASOFU. There is, so far—— 

Senator LAUTENBERG.—interrupting, but—— 

Dr. AKASOFU. There is, so far, no confirmation yet. 

Senator LAUTENBERG. Well, but—so, should we not intervene in 

trying to reduce the human contribution to—— 

Dr. AKASOFU. No, I am not saying that at all. 

Senator LAUTENBERG. No, I know you’re not saying that, but— 

I’d like you to say that. But the thing is that—at what point do you 

say—‘‘you,’’ I’m saying, generic ‘‘you,’’ lots of people—say, ‘‘Hey, we 

know that this is a phenomena that portends bad things for the 

human race.’’ And if we agree with that, then I say, ‘‘Well, what— 

at what point do we ask the politicians’’—Dr. Reiter said something 

about political hay being made of this, as opposed to science. I’m 

going to ask you about that. And so, at what point, Dr. Corell, does 

the alarm sound loudly enough that says, ‘‘Hey, let’s stop destroying our forests, let’s stop emitting these carbon dioxide chemicals— 

or results into the air’’? At what point do we take care to join in 

the protection of our environment and our lives? 

84 

Dr. AKASOFU. There is no question that we have to—I don’t think 

we can ever reduce the total amount of carbon dioxide in the air, 

but we should try to reduce the rate of increase. China is—— 

Senator LAUTENBERG. Dr.—— 

Dr. AKASOFU.—coming, India is coming—— 

Senator LAUTENBERG. Thank you. 

Dr. AKASOFU. Yes. 

Senator LAUTENBERG. Dr. Corell? 

Dr. CORELL. Yes, I think it’s pretty clear from the assessments 

that the scientific community have put together, a variety of them, 

whether it be IPC, national assessment of the U.S. or Canada or 

other countries around the world, our recent Arctic assessment 

clearly indicates that it’s time for action. And let me tell you why 

I believe so strongly it is time for action. 

If we were wise enough to take our CO2 and reduce it, like, over 

the next 100–150 years, OK—this is the result of some model studies—it would take the planet about 200 years for the CO2 to stabilize at some higher level, 700 or so, something—some number, 

quite a bit higher than we are today. It’ll take another 200 years, 

roughly, for the temperature to stabilize. So, we’re talking about 3- 

to 500 years before the planet’s stabilized. This is if we act, and 

it takes us 100 to 150 years to bring things down. 

The real sleeper is that sea-level rise will continue for probably 

1,000 or more years, with those increased temperatures that are a 

result of the higher levels of greenhouse gases. So, if that’s so—and 

we believe strongly, it is; this is IPCC results that came out of our 

study, as well—it seems logical that you ought to move that action 

time shorter to lower those temperature rates and to reduce the 

time for the stabilization to occur. 

So, I think the conventional wisdom within the scientific community is that we know enough now to take appropriate action. That’s 

a political issue. That’s an issue for you and others like you, to figure out how you take those steps, but we’re trying to suggest to 

you, it is timely, and it is now that such steps should—— 

Senator LAUTENBERG. Sure. 

Dr. CORELL.—be taken. 

Senator LAUTENBERG. Yes, a recommendation is being clearly 

made from the abundance—from the gathering of science—scientific knowledge that we have now, that we ought to get on with 

changing the pattern of what we see overtaking us, by intervening 

in the emission of CO2—and, again, I use deforestation as the example, but lots of things that we do as humans that violate the 

chances for our environment to succeed, as we know it. 

Dr. CORELL. Agreed. 

Senator LAUTENBERG. Dr. Reiter—unfortunately, we’re going to 

have to rush through this—you use the equivalent of the canary 

and the coal mine, in terms of malaria. And you know what that 

example, traditional—— 

Dr. REITER. Oh, they were British mines, I think. 

[Laughter.] 

Senator LAUTENBERG. Yes. So, you say that, and you don’t like 

the environmental activists using big talk of science to create simple, but false, paradigms. We have every right—and I’m not talking 

as a United States Senator, and I’m talking about every right as 

85 

a human being—to take what we hear and take what we read and 

take the evidence that we see in front of us, all kinds of indications 

that this world is a less accommodating place than it was. And 

you—your closing comment, I think, is one of the, kind of, more interesting, worrying about the weather, ‘‘Ah, don’t worry about 

that.’’ You’re right, why worry about a Katrina or a tsunami or frequency of these storms and the ferocity of these storms, when malaria is not shown to be anything that’s produced that’s essentially 

or totally a tropical disease or—it doesn’t indicate any real growth 

over the years, with substantial reductions, but a little spike. And 

you’re a scientist, and a very well educated one, but I think worrying about the weather, other than to—buying an umbrella or 

something like that, is probably a good idea. And so—and it’s consistent with what we want to do here; and that is, gather information that helps us spur some activity. That’s what we do. We’re— 

we have the political muscle to do things, unless it’s counteracted 

by structure of government. 

You know, I think that, you know, we have a suggestion now 

that as—that gas prices are so high that we ought to break environmental rules that exist now and get on with it, getting that gasoline price down. As they say in my old schoolyard—I grew up in 

a tough area—‘‘It ain’t gonna happen that way,’’ I can tell you. We 

can violate good environmental activities, and it’s not going to affect what we—what happens in gas prices. We’re—there’s a whole 

other thing there. 

And what we do here, as legislators, is react to things. We rarely 

ever do anything that’s creative in major magnitude that’s induced 

by other than a reaction to a—what happens. And I was listening 

to these discussions about the hundreds of years away, and—but 

we have an obligation to worry about those hundreds of years 

away. 

And when I see a report put out for the Navy that says, ‘‘The 

Navy’s got to be prepared in the second half of this century to fight 

off refugees seeking higher land,’’ we know now people will get into 

tire tubes and chance trips with shark-filled waters to get to this 

great country of ours. But if people are going to be deluged by 

water—and we’re talking about places that are not so distant from 

us, not necessarily Bangladesh, which is a—threatened, but the 

Netherlands and places like that. 

And, Mr. Chairman, you’ve experienced the worst of what happened in the—when a storm hits and the water rises above your 

capacity to contain it. So, we ought to get on with our task. And 

I would hope that the scientists would scare us a little bit and not 

let—let us feel too comfortable about, ‘‘Well, natural causes.’’ If 

there is a natural cause, there’s a natural cause, but if there isn’t, 

then we ought to do something about that share of it. 

Dr. REITER. May I answer your question? 

Senator LAUTENBERG. Sure. 

Dr. REITER. First of all, I didn’t mean to be flippant about the 

importance of the weather. What—and, again, I chose my own field 

as an illustration of problems of public health. 

I’m very glad that you say that I’m well educated. I like to think 

I could be better educated. 

86 

What I would urge you to do—and I would urge all of those who 

are interested, at least in the health aspects of this debate—is to 

look up the credentials, the scientific credentials of the principal 

exponents—proponents, I’m sorry—proponents of this disastrous 

situation, and compare them to the credentials, scientific credentials, of those who are essentially saying, ‘‘Well, wait a moment. 

What are you saying? We don’t have—we don’t have the evidence 

for this.’’ And if you look—I mentioned the IPCC, and I know that 

others have talked about the IPCC in a different way. I can only 

talk in the field of health. I can tell you, please look at—— 

Senator LAUTENBERG. So, you’re critical of the IPCC. 

Dr. REITER. Yes. Well, hang on. May I finish? If you look at the 

credentials of the lead authors—— 

Senator LAUTENBERG. Dr. Reiter, I must leave. And I don’t want 

to leave an empty chair and be disrespectful. So, I would say this, 

that when the National Academy of Sciences contributes their 

view, that there is pretty solid evidence there, and other distinguished science groups. I say, ‘‘Well, OK, you might be wrong.’’ 

Forgive me, I’ve got to go. 

Senator VITTER. Dr. Reiter, please finish up. I’m all ears. 

Dr. REITER. Well—no, I don’t want to continue about the IPCC— 

that’s a quite different issue—except to suggest that you look at the 

credentials of the lead authors. You will find that none of them— 

neither of them have any credentials in the field of public health. 

And if you look back to the reports of 2001 and 1995, you will see 

exactly the same. You will find that there are people there whose 

previous studies were on motorcycle crash helmets and the effects 

of cellular telephones on brain cancer. These are issues that really 

may be important, but, when we are talking about public—important public-health issues, we need to go to the people who specialize in public health. 

Senator VITTER. Actually, I was going to ask you about the IPCC, 

because I find it very interesting that both you and Dr. Corell refer 

to it, in, of course, completely different ways. I’d just ask you to follow up on your comments and your testimony. The IPCC exercise, 

how driven do you think it is by scientific rigor or politics and ideology? 

Dr. REITER. First of all, again, I can only speak for the health 

chapter, Chapter 8. In my opinion, we have to remember that this 

is the Intergovernmental Panel on Climate Change. Those—you 

may notice that I added to my dossier for you a paper—an article 

that nine of us, who consider ourselves leading experts in our field, 

published in The Lancet. We called it, ‘‘A Call for Accuracy: Malaria and Climate Change.’’ And, basically, none of us are on the 

panel—are on the Chapter 8 Panel. I can also tell you that I know 

of certain very highly respected persons that were nominated by 

the U.S. Government for lead authorship in Chapter 8 and were 

turned down in favor of people—one person who has not a single 

scientific article written in the whole career. 

So, I think, at least in my field, yes, there is a strongly biased 

selection of people, and I know, also, from people who have been 

expert reviewers, that the expert—the review system is very interesting. Normally in science, review is by anonymous peer review. 

And the—in the IPCC, it is the opposite. It is by nonanonymous 

87 

peer review. The expert reviewers discuss with the authors and 

come to so-called consensus. Now, when we did the U.S. Government evaluation in—about 5 years ago, it was the opposite, or, 

rather, those of us—well, let me go on to what the real opposite 

was. The discussions were public domain. You can actually find out 

what those discussions were by looking on the Web. You cannot see 

what the criticisms were of the authorship in the first and the second draft of the health chapter. In other words, what I feel is that 

a major investigation of the means by which the conclusions of the 

IPCC, at least in my field, are drawn, is overdue. 

Senator VITTER. Is it fair to say, then, that some of the traditional methods brought to scientific publication, like anonymous 

peer review, are abandoned in that U.N. process? 

Dr. REITER. Well, it certainly isn’t anonymous peer review. And 

it is very hard for those of us who are in this field—as I mentioned 

before, it is very hard for us to make some sort of scientific comment without either being ignored or being called ‘‘skeptics,’’ in a 

rather derogatory way. 

What I tried to say, policymakers like yourself increasingly depend on science for making policy. And, by the way, scientists depend a great deal on policymakers for their living. But in a democratic society, policymakers respond to the public conceptions of 

these issues. We scientists are not really very good at essentially 

communicating with the public; or, rather, I think the public 

doesn’t quite realize the way—the difficulty there is in conveying 

the way that science operates. 

Public conceptions are essentially shaped by the press. We scientists also find it very difficult to deal in a scientific way with the 

press. The press normally picks up on those things, as is obvious, 

that have, perhaps, the most extreme implications on life on Earth. 

On the other hand, those people who would like to speak on behalf of scientists, whether they are scientists or not, have a very 

much greater influence on the press, on public conceptions, and, 

therefore, on policymaking. And this, I feel, is not only in this field 

of climate change, but it also applies to many other issues that 

have become controversial or have become important in the way 

that policy is made. 

Senator VITTER. Thank you very much. 

Thanks to all of you. This has been quite significant and lengthy 

and wide-ranging hearing. I appreciate all of your testimony and 

participation. Again, several of you came from quite a distance, we 

deeply appreciate that. 

And, with that, the Subcommittee hearing is adjourned. 

[Whereupon, at 5 p.m., the hearing was adjourned.] 

(89) 

A P P E N D I X 

PREPARED STATEMENT OF HON. DANIEL K. INOUYE, U.S. SENATOR FROM HAWAII

In just the last few months a number of alarming new studies have come out on 

the projected and observed effects of climate change. These studies—and the testimony today—report that some projected climate change impacts are already occurring, and these changes are taking place at a faster pace than predicted. 

Latest estimates foresee a warming of the Earth’s temperature of somewhere 

around five degrees by the end of the century. By 2100, sea levels could be several 

feet higher than they are now, which would have devastating effects on coastal 

areas, including my home State of Hawaii and the other Pacific Island nations. We 

have already seen the powerful destruction tsunami or severe weather can have on 

our low lying islands, and this damage will be magnified under the National Oceanic and Atmospheric Administration’s (NOAA) projections of a one to three foot rise 

in sea level. 

Scientists also tell us that if trends continue as projected, we will see an increase 

in the already alarming growth in ocean acidification and coral bleaching events. 

These ocean changes would have virtually irreversible impacts on the fisheries and 

tourism industries and thus the Hawaiian economy. NOAA tells us that it took 

80,000 years for ecosystems to recover from the last mass extinction from ocean 

acidification. 

As I have noted previously, I also have serious concerns about the Administration’s efforts to suppress or downplay the findings of government scientists, particularly in this area of global climate research. It is only through broad dissemination 

of their research and public conversation that we can effectively tackle the causes 

of climate change. We must have the benefit of a full and open scientific assessment 

of the likely effects of climate change in the next 20 to 50 years, as already required 

by law. The Administration should not be avoiding and suppressing our scientists 

and their message, but rather listening to them attentively, and making plans to 

prevent dangerous interference with the climate system. 

I am very interested to hear more today about how climate change is going to affect all of us, what the Administration and others think we can do to prevent the 

worst impacts, and what we must do to prepare for the impacts that are already 

unavoidable. 

RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. DANIEL K. INOUYE TO

STEVEN A. MURAWSKI, PH.D. 

Question 1. There is a general scientific agreement that sea level rise is occurring 

at a global average rate of two millimeters per year. Sea level rise is projected to 

accelerate during the 21st century, with the most significant impacts in low-lying 

regions where subsidence and erosion problems exist. Rising sea level has worldwide 

consequences because of its potential to alter ecosystems and habitat in coastal regions. Sea level rise and global climate change issues in the coastal zone include: 

• Higher and more frequent flooding of wetlands and adjacent shores; 

• Increased flooding due to more intense storm surge from severe coastal storms; 

• Increased wave energy in the nearshore area; 

• Upward and land-ward migration of beaches: 

• Accelerated coastal retreat and erosion; 

• Saltwater intrusion into coastal—freshwater aquifers; 

• Damage to coastal infrastructure; and 

• Broad impacts on the coastal economy. 

Dr. Murawski, in your testimony you discuss the effects of sea level rise on islands and several atolls in the Northwestern Hawaiian Islands. I am more interVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00093 Fmt 6601 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
90 

1Karl, T. R., and K. E. Trenberth, 2003. Modern Global Climate Change. Science, 302: 1719– 

1723. 

ested in hearing about the potential impacts of sea level rise on the inhabited islands of the Pacific region. 

Can you tell us about the potential for adverse impacts from sea level rise on the 

population centers of the Central and Western Pacific, particularly with respect to 

port and road infrastructure, coastal habitats, living marine resources, and vulnerability of towns and villages to extreme coastal events, like tsunamis and typhoons? 

Answer. NOAA monitors sea level and uses the data to compute trends. The following table provides estimates of relative mean sea level trends based on analysis 

of tide gauge observations. The trends included in this table are ‘‘relative’’ measurements because they include both the effects of global sea level change and the local 

vertical land movement. The accepted range of global sea level rise by the scientific 

community is between 2.0 and 3.0 mm/yr. 

Station Trend Standard Error * 

Johnston Atoll 0.68 mm/yr (0.22 ft/century) 0.31 mm/yr 

Midway Islands 0.09 mm/yr (0.03 ft/century) 0.31 mm/yr 

Guam 0.10 mm/yr (0.03 ft/century) 0.09 mm/yr 

Pago Pago 1.48 mm/yr (0.49 ft/century) 0.56 mm/yr 

Kwajalein 1.05 mm/yr (0.34 ft/century) 0.51 mm/yr 

Chuuk Atoll 0.68 mm/yr (0.22 ft/century) 0.09 mm/yr 

Wake Island 1.89 mm/yr (0.62 ft/century) 0.35 mm/yr 

Honolulu 1.50 mm/yr (0.49 ft/century) 0.14 mm/yr 

Hilo 3.36 mm/yr (1.10 ft/century) 0.21 mm/yr 

Mera, Japan 3.66 mm/yr (1.20 ft/century) 0.12 mm/yr 

Aburastubo. Japan 3.33 mm/yr (1.09 ft/century) 0.14 mm/yr 

Tonoura. Japan 0.38 mm/yr (0.12 ft/century) 0.12 mm/yr 

Wajima, Japan –0.80 mm/yr (–0.26 ft/century) 0.13 mm/yr 

Xiaman, China 1.02 mm/yr (0.33 ft/century) 0.30 mm/yr 

* The standard errors provide a measure of uncertainty in the computed trends. 

Even with the low rates of relative sea level rise tabulated above, any increase 

or acceleration in the trends due to climate variability and change could have significant long-term effects on the remote ocean islands. This is because portions of 

many of the islands are low-lying with relatively flat topographies. Analysis of the 

tide gauge records from these islands show no apparent acceleration in the relative 

sea level trends to date. 

NOAA is working with local coastal managers and stakeholders in the Pacific, 

through the Pacific Services Center, to improve the development and delivery of risk 

management-related information products and services in the Pacific. The project is 

called Pacific Risk Management ‘Ohana (family) (PRiMO). 

On a larger scale, NOAA is working with other Federal agencies on the Climate 

Change Science Program, which is directing a range of research to address coastal 

sensitivity to climate change. 

URL References: 

http://tidesandcurrents.noaa.gov/sltrends/sltrendslglobal.shtml. 

http://www.csc.noaa.gov/psc/FHMPPI/. 

Question 2. As you know, we had tragic loss of life in Hawaii due to a dam failure 

after a period of torrential rains. Does the National Oceanic and Atmospheric Administration’s (NOAA) research suggest we will need to pay more attention to 

mudslides and infrastructure failure as the oceans warm and rise? 

Answer. One need only look at Central America’s experience with Hurricane 

Mitch in 1998, and California during the 1997–1998 El Nin ̃ o event, to see the potential devastation that intense precipitation can bring to a vulnerable region and its 

infrastructure. More recently, loss of life and property due to heavy rains were reported in Hawaii (February to March 2006) and the northeastern United States 

(May 2006), and the early onset of the summer monsoon in India killed 38 people 

(June 2006). NOAA research indicates that warmer climates will bring higher probabilities of extreme precipitation, even in locations where average precipitation may 

be decreasing. 1 NOAA data show increases in water vapor as the global climate has 

warmed, consistent with theoretical expectations. Thus, as the oceans warm and sea 

level rises the compounding effects of heavy rainfall and storm surge will need to 

be assessed to understand their full impact on coastal infrastructure. 

91 

2Sabine. CI., R.A. Feely, N. Gruber. R.M. Key, K. Lee, J.L. Bullister, R. Wanninkhof, C.S. 

Wong, D.W.R. Wallace, B. Tilbrook. F.J. Millero, T.-H. Peng, A. Kozyr. T. Ono. and A. F. Rios 

2004. The oceanic sink for anthropogenic CO2. Science. 305, 367–371. 3Orr J.C., Fabry V.J. Aumont 0., Bopp L. Doney S. C., Feely R.A. Gnanadesikan A. Gruber 

N., Ishida A. Joos F., Key R. M., Lindsay K., Maier-Reimer E. Matear R., Monfray P., Mouchet 

A. Najjar R. G. Plattner G.-K,. Rodgers K.B. Sabine C.L. Sarmiento J.L. Schlitzer R., Slater 

R.D., Totterdell I.J., Weirig M.-F., Yamanaka Y., and Yool A. 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature. 437(7059), 

681. 

Question 3. What is the range of marine ecosystem impacts that we might expect 

to see in the Western Pacific, and over what timeframes? 

Answer. Sea level rise is compounded by subsidence on islands such as Maui and 

Hawaii, which have rates of relative sea level rise of 3.5 to 5 mm/yr. Impacts to marine environments in the Western Pacific could include changes in water circulation, 

wave dynamics, sediment production and resuspension, transport of pollutants and 

nutrients, and possibly larval transport. Ecosystem-based management strategies 

can help mitigate the effects on reef environments. 

Changes to reef processes and reef distribution may occur in areas most vulnerable to changes in sea level. According to the U.S. Geological Survey, which has undertaken a study to understand and predict the response of reefs to accelerated sealevel rise, projected sea level rise will be particularly significant for low-lying coral 

atolls, many of which have maximum elevations of less than 5m above present sea 

level. Even in high island settings (e.g., main Hawaiian islands and Guam), large 

volumes of sediment stored at or near sea level could be exhumed and transported 

to reefs by increases in sea level. 

Coral ecosystems in the Western Pacific are also susceptible to other ramifications 

of climate variability and change, including coral bleaching caused by elevated sea 

surface temperatures and ocean acidification caused by increased carbon dioxide 

concentrations. There is not a strong consensus on the potential effects of climate 

variability and change on other coastal and marine island ecosystems. such as mangrove and seagrass ecosystems of the Western Pacific. 

Accelerating Ocean Acidification 

Question 4. A National Oceanic and Atmospheric Administration (NOAA) study 

released in April 2006 shows that rising temperatures are increasing the daily uptake of carbon dioxide by oceans. This changes the chemistry of seawater, making 

it more acidic, and having negative effects on corals and other marine life. NOAA 

oceanographers confirmed studies conducted in the 1990s showing that ocean acidification is occurring at ‘‘significantly increased rates,’’ and say ocean chemistry is 

changing at least 100 times more rapidly than it has during the 650,000 years preceding our industrial era. At current levels of carbon dioxide emissions, NOAA computer models predict that oceans will continue to acidify to ‘‘an extent and at rates 

that have not occurred for tens of millions of years.’’ 

Dr. Murawski, the National Oceanic and Atmospheric Administration’s (NOAA) 

recent study shows that ocean acidification is occurring at ‘‘significantly increased 

rates,’’ adversely affecting water chemistry and leading to ‘‘major negative impacts’’ 

on corals and other marine life. 

The National Oceanic and Atmospheric Administration (NOAA) has stated that 

ocean acidification could substantially alter the biodiversity and productivity of the 

oceans. Can you tell us when we might see the effects of ocean acidification on the 

biodiversity and productivity of the ocean in the Pacific islands region? 

Answer. While many of the models applied to describe the projected trends in 

ocean acidification have centered on the Pacific Ocean, the models are not specific 

to the Pacific islands region and uncertainty remains regarding the precise timing 

and biological impacts. Recent estimates indicate roughly half of the anthropogenic 

CO2 released since the industrial revolution has been absorbed by the surface 

waters of the world’s oceans. 2 This has resulted in probably the most dramatic decrease in ocean pH for the past 400,000 years. 3 This process of ocean acidification 

imparts an important control on the degree to which the surface waters are supersaturated with respect to carbonate minerals (i.e., saturation state), from which 

some marine organisms construct their skeletal structures. Studies on hermatypic 

corals, coralline algae, mesocosm coral reef communities and natural coral reef ecosystems have shown that the calcification of a diverse selection of organisms and 

natural systems correlate strongly with aragonite saturation state. 

The aragonite (calcium carbonate) saturation state has already declined from preindustrial levels by more than 10 percent in the tropics and could drop a further 

20–30 percent by 2100 if CO2 emissions continue as projected by the Intergovernmental Panel on Climate Change (IPCC)1S92a ‘‘Business as Usual’’ scenario (1995). 

92 

4Guinotte J. M., Buddemeier R. W., and Kleypas J. A. 2003. Future coral reef habitat marginality: temporal and spatial effects of climate change in the Pacific basin. Coral Reefs, 22(4). 551. 

Model results based on the more conservative IPCC SRES B2 emissions atmospheric 

CO2 increase scenario, together with laboratory estimates of the sensitivity of corals 

to ocean acidification, suggest that the waters of the Pacific islands region will may 

not support optimal coral calcification rates beyond approximately 2050 ±20 years. 4

These scenarios are projections of what is likely to occur with regards to the broad 

oceanic changes in saturation state. However, the projections are less likely to accurately predict coastal zone conditions, where complexities can arise involving 

buffering by dissolution of carbonate minerals. Furthermore, the models assume an 

equitable biologic response to changes in saturation state while it is well demonstrated that the magnitude of the effects is not universal and varies between species and even among individual organisms within the same species. 

We are only beginning to understand how rapid changes in ocean chemistry will 

impact marine biota. The magnitude of the effects is not universal and varies between species and even among individual organisms within the same species. It is 

not yet fully understood how such changes in calcification rate will impact marine 

ecosystems at the community scale. For example, it has been suggested that although the calcification rates of corals are expected to decrease in response to ocean 

acidification, organisms such as seagrasses and algae could benefit from the increased CO2 and thereby hasten the community shift to a lower biodiversity environment. In addition to impacts resulting from ocean acidification, marine ecosystems will also respond to other climate-and human-induced stresses (e.g., increasing sea surface temperature, rising sea level, overfishing. etc.). 

Studies have begun to investigate the synergistic effects of decreased saturation 

state and increased temperature on selected coral species. It is difficult to determine 

the combined effect these stressors will have, and the precise timing of any impacts. 

As a consequence of our current uncertainty with regards to the anticipated coastal 

changes in saturation state, the variability in the biological response to such 

changes, and the complexities of other climate change variables, we cannot be certain of the exact rates, final extent, and detailed geographic distributions of the impacts of ocean acidification. The current prevailing scientific view is that such 

changes will largely be detrimental to coral communities and that such changes will 

likely be experienced within this century. 

Question 5. What will be the effects of ocean acidification on the corals and associated fisheries and tourism businesses that the Pacific islands are so dependent 

upon? 

Answer. The full range and magnitude of the biological and biogeochemical effects 

of ocean acidification are still so uncertain that a reliable and quantitative estimate 

of the likely socioeconomic effects is not yet possible. 

Question 6. What future programs or products are planned by NOAA to monitor 

the oceans’ response to growing carbon dioxide levels and provide decision-makers 

with advice on mitigation options, particularly in the Pacific? 

Answer. Ocean acidification is an emerging issue: hence current understanding 

does not offer many specific mitigation options at this time. Efforts have begun to 

develop observatories at select U.S. coral reefs that monitor a Reef Metabolic Index 

(RMI) designed to track broad changes in community-scale calcification. These observatories will expand on existing monitoring stations, remote sensing efforts, and 

near-reef carbon measurements to measure overall biological performance of the ecosystem. In addition, efforts have begun using satellite remote sensing to document 

the coastal and global long-term distribution of the phytoplankton Emiliania 

huxleyi, which is a key algal species demonstrated to exhibit sensitivity to changes 

in ocean pH. This kind of information will be essential for decision-makers to develop an understanding of the magnitude and extent of the changes that are occurring within U.S. coral reef ecosystems over time, and for developing and testing the 

effectiveness of newly developed mitigation procedures. 

RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. FRANK R. LAUTENBERG TO

STEVEN A. MURAWSKI, PH.D. 

Question 1. In your written testimony you indicate that scientific uncertainties remain on how much of the observed warming is due to human activities. Given the 

complexity of global climate change, that past observations of the climate are uncertain, and that projections are being asked looking a century or more into the future, 

is it inevitable that there will be uncertainties, no matter how much research is 

done? 

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1Moss. R., and S. Schneider, 2000. Uncertainties, in Guidance Papers on the Cross Cutting 

Issues of the Third Assessment Report of the IPCC, edited by R. Pachauri, T. Taniguchi, and 

K. Tanaka, Intergovernmental Panel on Climate Change (IPCC), Geneva. 

Answer. The short answer is that yes, there will be uncertainties no matter how 

much research is done because the climate system is not a completely deterministic 

system. Uncertainty associated with climate variability and change can have many 

sources, including the nature and quality of the available data: the ability of models 

to capture processes and their relationships (including predictability); and other factors related to the impacts of human behaviors 1 (Moss and Schneider, 2000). There 

is also uncertainty about the natural interactions among the various components of 

the climate system. Given the impact uncertainty has on our efforts to understand, 

communicate, and adapt to climate change, the scientific community continues to 

pursue this area of research and has taken steps in recent years to address the nature of uncertainty in their assessment efforts, as reflected in the U.S. Climate 

Change Science Program (CCSP) and the Intergovernmental Panel on Climate 

Change (IPCC) reports. 

For example, the CCSP Synthesis and Assessment Product 5.2 is intended to further develop this topic through the synthesis, assessment, and communication of 

what is known about the character and magnitude of uncertainty, as it applies to 

climate, and to address some potential approaches to decision-making given the uncertainty. This report will address uncertainty related to decision support activities, 

ranging from the conduct and communication of research to the actual consideration 

and use of scientific knowledge and information products in decision-making. 

Research is also leading to improved understanding of natural climate variability 

and its impacts. Current global climate models are improving our understanding of 

global climate sensitivity, ocean dynamics, climate feedbacks, and trends in extreme 

weather events and enhancing our ability to forecast climate on seasonal time scales 

and beyond. As models continue to improve, uncertainties in climate response will 

continue to be reduced resulting in a better understanding of current and future climate projections. 

Question 1a. Does NOAA make decisions on many matters governing resource 

management (e.g., fisheries management) where there are also significant uncertainties? 

Answer. NOAA develops fishery management plans (FMPs) and amendments, 

under authority of the Magnuson-Stevens Fishery Conservation and Management 

Act, based upon the best scientific information available (Section 301(a)(2)). Where 

there are significant uncertainties, NOAA supports using a precautionary approach. 

Question 1b. What metric is being used to document how much uncertainty exists 

and the progress being made to reduce uncertainties? 

Answer. NOAA is tracking research progress in reducing uncertainty through two 

performance measures under the Government Performance Results Act (GPRA): 

1. Reduce the Uncertainty in Model Simulations of the Influence of Aerosols on 

Climate, and 

2. Reduce the Uncertainty in the Magnitude of the North American (NA) Carbon Uptake. 

These high-level NOAA Corporate performance measures aim to track our skill 

in reducing uncertainty in estimates of North American carbon uptake from the atmosphere and in model simulations of aerosol impacts on climate. Improvements in 

measurements of carbon uptake will be important in validating carbon trading options at the regional level (e.g., carbon trading markets being discussed in CA and 

New England). The uncertainty of NOAA estimates of North American carbon uptake has decreased each year since 2003 as the NOAA North American carbon observation network approaches completion. 

Question 1c. What efforts are underway that relate one uncertainty to another 

and that amalgamate individual uncertainties into an overall uncertainty, determining whether an individual uncertainty is important or not? 

Answer. The overall uncertainty in the uptake of carbon by the North American 

continent is a suitable high-level measure that represents considerable effort to 

identify and attribute regional sources and sinks of carbon dioxide and other related 

gases. Several lower-level, more specifically focused measures are used to guide our 

efforts. Work is currently underway to employ both vertical observations from the 

network and analysis modeling to generate maps of regional emissions of carbon 

gases. The early maps, based upon the network at this time, are promising. They 

suggest a very real opportunity to provide, within a few years, emission and uptake 

maps on spatial and temporal scales that are useful for making regional decisions 

94 

on managing carbon. As regional sources and sinks are identified and quantified, 

uncertainty decreases considerably. This effort is a necessary component of the 

North American Carbon Program, which involves a host of universities and many 

U.S. agencies, including NOAA, the National Aeronautics and Space Administration, 

Department of Energy (DOE), U.S. Department of Agriculture, U.S. Geological Survey, and the Environmental Protection Agency, among others. The goal is to build 

a system that can measure the transfer of carbon between land and atmosphere 

across the continent to vastly improve our understanding of its cycling. Subsequently, the U.S. Climate Change Science Program (CCSP) embraced this effort and 

a good part of its coordination is now conducted through the Carbon Cycle Interagency Working Group of the CCSP, of which NOAA is a major player. The idea 

was that measurements of ecosystem emissions or uptake (done or overseen by 

other agencies) should be verifiable with a vertical network of atmospheric observations (provided by NOAA and its partners) combined with coupled models that accounted for transport, fires, human emissions, and ocean influences. The greater understanding that comes with this effort will allow attribution of sources, lending 

considerable support to management and mitigation options for society. 

A second benefit of NOAA’s carbon effort is the potential use of satellites to detect 

carbon emissions and uptake. Today, satellites are incapable of measuring CO2, 

with the accuracy and precision needed for such a study. However, that does not 

belie their potential use in the future, and their ability to provide high-frequency 

spatial coverage is unsurpassed. Because satellites measure total column amounts, 

success of satellite measurements requires a ground-based vertical network to support them. Satellites also require the calibrations of the ground based network, as 

sensors tend to drift, given that they operate in an inhospitable environment. 

A third area where we are focused on reducing uncertainty is through our work 

to improve understanding of the growth, distribution, and chemistry of aerosols in 

the atmosphere. Unlike carbon dioxide or other long-lived greenhouse gases, uncertainty in estimating the contribution of aerosols to global warming is significant. 

Current information suggests that aerosols have predominantly a cooling effect, and 

the effect could be large. Because aerosols are not well-mixed in the atmosphere, 

their effect on cooling or heating depends upon their distribution, size, and chemical 

composition. NOAA and its partners (DOE, University of Colorado, and others) currently are developing an observational record of aerosols at key locations around the 

world. We also are studying aerosol and related processes in the field and laboratory 

to improve our understanding of their effect on climate. By using these findings to 

improve aerosol-climate models, we systematically reduce the uncertainty in our estimate of their overall contribution to climate. 

Work is also progressing on the development of an index that separates uncertainties in climate projections into three components: (1) sub-seasonal: (2) seasonal; and 

(3) decadal. Once completed, this index will allow us to assess the uncertainties in 

climate projections for time scales ranging from days to decades. 

Question 2. What studies is NOAA undertaking to determine how available information on climate change is being and can be used, and what the role is of uncertainties in decision-making? 

Answer. The Regional Decision Support (RDS) program of NOAA’s agency-wide 

Climate Mission Goal includes a focused research capability designed to address the 

role of climate and climate information in decision-making processes for climate-sensitive regions and sectors. The RDS effort harnesses the intellectual capabilities of 

NOAA and the external scientific community through a competitive grants process, 

and is conducted in partnership with NOAA’s operational and transition activities 

to ensure that NOAA’s climate services are well oriented to the needs and capabilities of the constituencies it serves. The RDS research effort is composed of two programs that address the use of climate information in decision-making: the Regional 

Integrated Sciences and Assessments (RISA) Program. and the Sectoral Applications 

Research Program (SARP). These programs complement and enhance each other, 

approaching the critical research issue of climate information for decision support 

from a regional and sectoral perspective. NOAA has more than a 10-year investment 

in research on the impacts and potential research applications associated with climate variability and change. This research has mostly been focused on shorter time 

scales (seasonal to interannual), but has provided useful insight into society’s demand for and the potential value of climate information over multiple time scales, 

from intraseasonal (weeks/months) through decadal. 

In addition to the RDS research effort, NOAA is leading the development and production of two Climate Change Science Program (CCSP) Synthesis and Assessment 

Products (SAPs) that address the use of climate information and the role of uncertainty in decision-making: 

95 

a) CCSP SAP 5.2: Best practice approaches for characterizing, communicating, 

and incorporating scientific uncertainty in decision-making; and 

b) CCSP SAP 5.3: Decision support experiments and evaluations using seasonal 

to interannual forecasts and observational data. (http:// 

www.climatescience.gov/Library/sap/sap5-3/sap5-3prospectus-final.htm) 

NOAA supports similar work internationally by funding the International Research Institute for Climate Prediction, whose mission is to enhance society’s capability to understand. anticipate, and manage the impacts of seasonal climate fluctuations in order to improve human welfare and the environment, especially in developing countries in Asia, Africa, and the Americas. 

Question 2a. If any studies of this nature have been completed by NOAA, what 

were the findings? 

Answer. Studies conducted by the NOAA RDS effort have addressed the use of 

climate information in a suite of diverse regions and sectors, including the following: 

Sectors U.S. Regions 

Natural hazard preparedness Pacific Islands 

Agriculture and food security Pacific Northwest 

Water resource management California 

Coastal management Southwest 

Public health Southeast (two regions) 

Urban New England 

Ecosystem management Intermountain West 

Conservation 

Transportation 

Energy 

There are certain sectors where NOAA has been more active, and thus has more 

knowledge of the role of climate and climate information, including the nature and 

implications of uncertainty. Examples of such sectors include fire management, public health, water management, and natural hazards preparedness. Other sectors, 

such as coastal, urban, and conservation, are beginning to articulate their interest 

in climate. Two sector-specific examples of NOAA’s work follow: 

• Climate information is being used to predict pre-season fire potential for the 

United States. NOAA-funded climate researchers, USDA-Forest Service, and 

the National Interagency Coordination Center have developed a series of National Seasonal Assessment Workshops to enhance fire preparedness, prescribed 

fire management, and awareness of the connections between climate and fire. 

Participants synthesize and analyze climate, forestry, and fire science information to predict fire potential for the upcoming fire seasons. 

• Climate information is being used to a limited extent by municipal water managers. Through an ongoing NOAA-supported study, we have found that municipal planners use a diverse set of climate information, including climate/water 

indices, and some use paleo data to inform thinking about long-term climate. 

Some municipal water providers create their own system-specific indices to determine what might trigger water supply and demand issues for their water 

system. 

Specific findings of the RDS studies can be found on the websites for the RISA 

and SARP activities: http://www.climate.noaa.gov/cpolpa/risa/ and http:// 

www.climate.noaa.gov/cpolpa/sarp/. Although the findings of NOAA’s research 

vary depending on the characteristics of the decision-making challenge at hand, this 

body of work underscores the potential value of climate information for decisionmaking, and the demand for climate information. 

In addition. there are some overarching lessons that have been generated regarding the relationship between humans and climate, and the characteristics of effective decision support efforts that take uncertainty into account. Examples include 

the following: 

• Climate forecasts are often just one tool utilized by decisionmakers in addressing a resource management challenge. Climate forecasts are not deterministic; 

the utilization of climate information by decision-makers requires a synthesis 

of science, practical resource management strategies and an anticipation of the 

requirements for the health and welfare of human society and the environment. 

• Effective climate decision support systems include sustained processes for interaction and collaboration between the producers and users of climate informaVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00099 Fmt 6601 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
96 

tion. Users include decision-makers such as farmers, water managers, public 

health and safety managers and others responsible for managing climate-sensitive sectors. 

• Climate information often requires specific tailoring before it can be utilized by 

users. For example. climate-based forecasts of total water volume might be useful for one type of water resource decision, but another type of decision might 

require information about the onset of seasonal precipitation. 

• Communication methods must take into account the various levels of uncertainty associated with both the climate information and the context within 

which decisions are being made (i.e., markets, culture, other environmental 

stressors). 

Question 2b. How does NOAA plan to build on these efforts to assist the public 

and government decisionmakers? 

Answer. The NOAA Climate Goal and its component programs are dedicated to 

providing the Nation with climate services through an ‘‘end-to-end’’ process (observations, analysis, prediction, application, delivery), and over all time scales. The 

NOAA Climate Program Office improves climate services through its five components: 

• The Climate Observations and Analysis (COA) Program—The COA program’s 

goal is to describe and understand the state of the climate system through integrated observations, analysis, and data stewardship. 

• The Climate Forcing (CF) Program—The CF program’s goal is to reduce uncertainty in the information on atmospheric composition and feedbacks that contribute to changes in Earth’s climate. 

• The Climate Predictions and Projections (CPP) Program—CPP program’s goals 

are to provide (1) climate forecasts for multiple time scales to enable regional 

and national managers to better plan for the impacts of climate variability, and 

(2) climate assessments and projections to support policy decisions with objective and accurate climate change information. 

• The Climate and Ecosystems (C&E) Program—C&E program’s goal is to understand and predict the consequences of climate variability and change on marine 

ecosystems. 

• The Regional Decision Support (RDS) Program—RDS program’s goal is to build 

effective bridges between users and producers of climate information so that 

public and private sector decision-makers have access to and participate in the 

creation of new knowledge, processes, tools, and products to improve risk management, response, and mitigation in sectors sensitive to climate variability and 

change. 

The National Integrated Drought Information System (NIDIS) is an example of 

an end-to-end process covering multiple time scale and climate program components. The vision for NIDIS is a dynamic and accessible drought information system 

that provides users with the ability to determine the potential impacts of drought 

and the associated risks they bring, and the decision support tools needed to better 

prepare for and mitigate the effects of drought. Implementation of NIDIS will require: 

• Building a national drought monitoring and forecasting system; 

• Creating a drought early warning system; 

• Providing an interactive drought information delivery system for products and 

services, including an Internet portal and standardized products (databases, 

forecasts, Geographic Information Systems (GIS), maps, etc.); and 

• Designing mechanisms for improved interaction with the public (education materials, forums. etc.). 

Question 3. In your written testimony, on page 3, you list various types of assessment efforts that NOAA has been involved in. You do not mention that NOAA 

played an important role in the various sectoral, regional, and national components 

of the U.S. National Assessment, including leading the assessment of the likely impacts on coastal areas and marine resources and sponsoring several regional studies. Can you explain why the important results that emerged from these studies 

were not discussed in your testimony? 

Answer. The work from the U.S. National Assessment report on coasts and marine resources is mentioned and cited in the testimony. For example, on page 4 of 

the testimony the summary article by Scavia et al. (2002) is referenced. Several 

studies cited in the U.S. National Assessment report (e.g., Tynan and DeMaster, 

97 

2 Imbrie, J.I., E.A. Boyle, S.C. Clemens, A. Duffy, W.R. Howard, G. Kukla, et al. 1992. On 

the structure and origin of major glaciation cycles: 1. Linear responses to Milankovitch forcing. 

Paleoceanography. 7: 701–738. 3 Jones, P.D., T.J. Osborn, K.R. Briffa, C.K. Folland, E.B. Horton, L.V. Alexander, et al. 2001. 

Adjusting for sampling density in grid box land and ocean surface temperature time series. Journal of Geophysical Research. 106: 3371–3380. 4Parker, D.E., C.K. Folland and M. Jackson 1995. Marine surface temperature observed variations and data requirements. Climatic Change, 31: 559–600. 5 COHMAP Project Members 1988. Climate changes of the last 18,000 years: Observations and 

model simulations. Science, 241: 1043–1052. 6 Houghton, J.T. et al. 2001. Climate Change 2001: The Scientific Basis, Cambridge University 

Press. 

1997; Brown, 1997) are also cited in the testimony. The U.S. National Assessment 

report on coasts and marine resources was published in 2000. The science on this 

topic is rapidly evolving. The testimony provides a synopsis of important recent findings, especially over the 6 years since the 2000 report was published on such topics 

as ocean acidification, which had not been well-studied at the time of the U.S. National Assessment. 

Question 4. The regional, sectoral, and national results of the National Assessment formed the basis for the chapter on impacts and adaptation in the U.S. Climate Action Report 2002 that was endorsed by all agencies before being submitted 

to the U.N. Framework Convention on Climate Change as the official government 

position. Have any recent scientific developments caused NOAA to reevaluate its positions regarding the potential consequences of climate variability and change, both 

based on the national level and for the regional and sectoral efforts that it led and/ 

or sponsored? 

Answer. Recent research results from prominent Earth system scientists are garnering considerable attention, particularly in the area of sea level rise, and potential 

trends in extreme events such as hurricanes, floods, and drought. These results warrant further attention, investigation, and dialogue across the Federal agencies and 

in partnership with Congress. For example, the experience over the past several 

years throughout the U.S. West with severe sustained drought has raised a broad 

range of issues ranging from drought management to assessing long-term drought 

trends, which have important implications for fire and water management, and ecosystem sustainability. NOAA is responding in the context of the development and 

cross-agency implementation of the National Integrated Drought Information System (MIDIS). We expect there will be more such calls for a range of climate information services responsive to the needs of local, state, and Federal managers. 

Question 5. In your written testimony, you indicate on page 5 that ‘‘Remarkably 

only a few documented extinctions occurred in terrestrial and marine ecosystems 

during the ice age cycles... .’’ You indicate that one reason for this was likely 

that, overall, the climatic changes were ‘‘slow compared to the changes in the current millennium.’’ 

Given that the human influence has been primarily during the latter 20th century 

rather than over the entire millennium, would it be fair to say that changes during 

the last glacial period were very slow compared to the changes over the past 50 

years, and that the rate of change might well be so fast that assurances that species 

survived glacial cycling likely provide no assurance that there will be remarkably 

few extinctions as a result of human-induced warming? 

Answer. Yes, it would be fair to say that survival of many species during glacial 

cycling likely provides no assurance that there will be few extinctions as a result 

of human-induced warming. Two aspects of human-induced warming might cause 

species to become extinct in the future. One is the rapid rate of human-induced 

warming, roughly ten times faster than the rate observed in the paleoclimate record 

(the average Earth temperature warmed 4°C in a few thousand years at the end 

of the last Ice Age.2 compared to the warming of 0.7°C in the past 100 years.3, 4 The 

second aspect is that climate is expected to reach conditions outside the range (of 

temperature, precipitation, ocean pH, and ocean and atmosphere circulation) experienced during the glacial cycles.5, 6 Unlike glacial times, future changes will occur in 

a world with 6 billion people within ecosystems now fragmented by human land use. 

Question 6. A recent paper appearing in Nature (Grottoli et al.) indicates that a 

species of coral has been found that seems to be able to adapt to higher temperatures. In your testimony, you indicated that both the temperature increase and 

ocean acidification are threats to the coral. Is this newly identified species of coral 

also able to survive the ocean acidification that will be caused by the higher CO2

concentrations? 

98 

7Grottoli, A.G., L.J. Rodrigues, and J.E. Palardy. 2006. Heterotrophic plasticity and resilience 

in bleached corals. Nature. 440: 1186–1189. 8Langdon, C., and M.J. Atkinson. 2005. Effect of elevated pCO2 on photosynthesis and calcification of corals and interactions with seasonal change in temperature/irradiance and nutrient 

enrichment. Journal of Geophysical Research—Oceans. 110(C9): C09S07. 

Answer. Grottoli et al. 7 found that one of the corals they studied, the branching 

coral Montipora capitata, was able to switch to feeding on zooplankton for its predominant food source. This allows it to better survive a bleaching event, but does 

not change its tendency to bleach. A recent study 8 on the impacts of elevated carbon 

dioxide on coral photosynthesis and calcification included M. capitata as part of the 

coral assemblage investigated. Although M. capitata appears to survive bleaching 

better relative to other corals 7 it is not immune from the effects of ocean acidification. Rather, M. capitata was found to exhibit a pronounced reduction in calcification rate in response to elevated carbon dioxide. 

Question 7. In your written testimony you indicate that, apparently associated 

with an increase in air temperatures, ‘‘the density of krill... has decreased by 

more than 90 percent in the region since 1976’’ and that this is having associated 

impacts on other species. Is this evidence of a dangerous anthropogenic interference 

with one of nature’s key ecosystems? 

Answer. The reasons for the decline in krill populations in Antarctica are not 

clear and cannot be explained fully. Many factors are believed to have contributed 

to the declines. We know that the Southern Ocean is undergoing a warming trend, 

which likely influences ocean circulation and sea-ice dynamics. Although these factors likely affect krill populations, the definitive link between climate change and 

anthropogenic interference has not been established. Due to its relative isolation, 

the direct anthropogenic effects in Antarctica are substantially less than in other 

parts of the world. It also is clear that the decline in krill populations is not directly 

related to overfishing. The present annual harvests in Antarctica are around 

100,000 tonnes, while the International Commission for the Conservation of Antarctic Marine Living Resources precautionary catch limits are more than 4 million 

tonnes. The catch limits are based on relatively recent surveys. There is considerable debate in the scientific community concerning the role indirect effects may have 

played in this ecosystem. As my testimony indicated, reduced sea ice is generally 

believed to have played a major role in reduced krill populations. Other causal effects are difficult to quantify. Evidence suggesting anthropogenic interference with 

the Antarctic ecosystem is not clear and considerable debate exists among scientists. 

We are addressing these concerns, but it will be some time before cause and effect 

is clearly delineated. 

Question 7a. If not at 90 percent, at what point would it be that NOAA management would strongly advocate publicly and with the Administration for actions to 

slow and limit further changes in the climate? 

Answer. NOAA will continue to carry out our mission to ‘‘understand and describe 

climate variability and change to enhance society’s ability to plan and respond’’ 

through our research, observations, and modeling capabilities, but we do not focus 

on advocacy. As a key part of the U.S. Climate Change Science Program, we are 

working on developing synthesis and assessment products intended to provide the 

best possible scientific information, developed by a diverse group of climate experts, 

for the decision community. These reports are designed to address a full range of 

scientific questions and evaluate options for responses that are of greatest relevance 

to planners and decision-makers. 

RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON FRANK R. LAUTENBERG TO

DR. SYUN-ICHI AKASOFU

I am glad to have this opportunity to express my thoughts on the global warming 

issues in more detail, since it was not easy to do so during the testimony due to 

the time constraints. I have tried to answer all your questions. 

If you have further questions, please do not hesitate to contact me. Also, I am 

more than happy to explain more when I come to Washington, D.C., next time. 

Question 1. Regarding Figure 1 in your written testimony—Why is it that the 

graph indicating sources of energy ends at 1985 and does not show the associated 

increase of energy use with temperature up to the present? 

Answer. I received the invitation to testify while I was in Tokyo and had only a 

few days to prepare the written document by working with my staff in Fairbanks, 

Alaska, via phone and fax. The original Figure 1 in my testimony was prepared 

under these difficult circumstances. 

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Question 1a. Could you please provide an updated plot that extends the energy 

record to at least the year 2000, or preferably extends both the emissions and temperature records to 2005? 

Answer. I am glad to have an opportunity now to provide you with an updated 

version of Figure 1, which is now Figure A in this correspondence. I also prepared 

a new one with the CO2 data alone (Figure B), which I wanted to use to begin with. 

Please notice that the range of temperature changes is much greater in the Arctic 

than the global average provided by the IPCC Reports. 


resp1.eps
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Question 2. In Figure 1, is the mid–20th century jump (i.e., increase and then decrease) in the Arctic temperature record that you show a usual occurrence; that is, 

is there any indication that such sudden and short duration warming periods have 

occurred previously? 

Answer. Before 1850 or so, there were not many thermometers in the whole 

world. Therefore, we have to rely on proxy data. Unfortunately, a 1000-year temperature record based on the tree ring analysis by Mann (the so-called ‘hockey 

stick’) used most frequently and prominently in IPCC Reports and others, is now 

very controversial; please see your item 7. 

The most reliable data for the past are deduced from ice cores (O18). We are fortunate to have such a high-resolution (in time) data from Severnaya Zemlya (Figure 

5 in my testimony, which is reproduced here as Figure C). There have been a number of fluctuations, large and small, superposed on a linear increase (which is discussed in conjunction with your Item 8). 

Please note that the top, middle, and bottom traces agree reasonably well, confirming the accuracy of all the data shown. 


resp2.eps
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Question 3. Might there be problems with the data set that is used to generate 

this record, especially given the limited time over which observations are available 

in the Arctic? Could you supply some indication of the number of measurements 

going into the Arctic record and the percentage coverage of the Arctic that is represented over time by this record? 

Could it be that only one part of the Arctic was as warm in the mid 20th century 

as it is currently and other parts that did not warm were not represented in the 

temperature record of Polyakov? 

Answer. The top of Figure D shows the same temperature record as that of Figure 

A (or Figure 1 of my testimony). Please note that added to it, as an insert, is the 

distribution of the stations from which data was used. They are distributed mostly 

along the entire arctic coast. (Russia actually kept excellent temperature records 

even in Siberia and recorded carefully watched changes in natural phenomena, better than some other places in the world.) 


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The bottom of Figure D shows sea water temperature data. They are taken from 

the middle of the Arctic Ocean as the insert shows. 

Please note that the temperature record similar to figure A is shown on page 23 

of the ACIA Report ‘‘Impact of a Warming Arctic’’ (Figure 4 of my testimony); it includes continental data in the Arctic. It shows a larger increase after 1970 than in 

1940, because a very prominent warming occurred in the continental Arctic, which 

is disappearing during the last decade or so, as shown in Figure 3 of my testimony. 

Question 4. With the Arctic indicated to be as warm in the mid–20th century as 

at present, and with that warming lasting for a time comparable to the time of the 

current warming, is there evidence that indicates that the same types of changes 

in sea ice, permafrost, glacial melting, species shifts, etc. occurred as we are seeing 

at present? Do the Indigenous elders recall such warm periods and the appearance 

of the new birds and other species that are now occurring in the Arctic? 

Answer. Sea ice: The only reliable, long-term data before 1950 are observations 

of the southern ice edge in the Norwegian Sea (Figure E; my testimony Figure 7b). 


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Please note that the range of changes during 1920–1960 (corresponding to what you 

term ‘the mid-20th century jump’ was much larger than the present change after 

1970; the present change is much smaller than that during the mid-20th century 

in the Norwegian Sea. Please note also a linear change similar to the ice core 

change that will be discussed in your Item 8. 


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Permafrost: Figure F shows the best available temperature data on permafrost, 

from both Siberia and Fairbanks. Please note that the temperature was decreasing 


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until 1970, in spite of the fact that the amount of CO2 began to increase rapidly 

in about 1940. Permafrost temperature closely follows air temperature (please compare Figure F with Figure A). 

Glaciers: Old Russian records show that many Alaskan glaciers have been receding since 1800 or earlier (Figure 7a in my testimony). The recession did not start 

in 1970; please see also Figure G. Changes in the European Alps are similar to it. 


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Many recent TV programs show large blocks of ice falling off the glacier terminus, 

implying that this phenomenon is a manifestation of global warming. Most people 

do not realize that glaciers are actually ‘‘rivers of ice’’ (where ice flows) and that 

ice has been falling off glacier termini for thousands and thousands of years. 

Others: Some species are obviously quite sensitive to temperature changes; fish 

are quite sensitive to sea water temperature changes. I am not an expert on such 

issues, but happen to have an interesting figure (Figure H), which shows changes 


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of fish populations in the Pacific. It seems that such changes are a common occurrence. 

Question 5. In your written testimony you state that ‘‘It is also important to note 

that both the Arctic and global temperatures began to decrease in about 1940, when 

our release of greenhouse gases began to increase rapidly. Thus the increase-decrease between 1920 and 1970 must be natural change.’’ The most often mentioned 

natural factors that could be responsible for a warming are a reduction in the 

amount of volcanic aerosol and an increase in solar radiation. If these factors are 

indeed responsible for this warming, it would seem to lead to the conclusion that 

the Arctic climate is very, very sensitive to slight changes in the amount of energy 

driving the climate system, in that the volcanic and solar influences, in terms of 

Watts per square meter, have been relatively small. Thus, should not your assertion 

that these changes are natural make us very, very concerned about the climatic 

changes that lie ahead given the large changes in atmospheric radiation being 

caused by the continuing human-induced increases in the concentrations of greenhouse gases? 

Question 6. The detection and attribution studies reported on by the IPCC conclude that the warming prior to about 1940 was likely due partly to natural factors 

and partly to the release of greenhouse gases, and that the subsequent cooling was 

due mainly to the increasing emissions of SO2 and possibly a slight diminution in 

solar radiation and return of volcanic eruptions. These carefully done detection and 

attribution studies, endorsed by the IPCC, make clear that such analyses must include consideration of all forcing factors (and that there are natural and human-induced factors that induce warming and other factors that can induce cooling). It 

therefore seems to be quite a jump to suggest that the mid-century part of the 

record must be entirely due to natural factors without considering the human influences also likely to have exerted influences throughout the 20th century. What steps 

does your analysis take to conclude that the full set of human-induced factors is not 

having an influence? 

Answer to Questions 5 and 6. I believe that all the IPCC GCMs consider effects 

of observed volcano effects (past major eruptions), solar output changes, aerosol effects (SO2), etc., and their positive/negative feedback effects as well, quantitatively 

with the best knowledge available. However, they cannot reproduce the mid–20th 

century jump. It is very hard to explain the 1940–1970 decrease, particularly since 

CO2 began to increase rapidly at that time; the initial increase is also hard to explain. Therefore, at this stage, I must come to the same conclusion I did earlier during my oral testimony, as I describe below again. 

We always come up with interesting ideas about how to explain natural phenomena, but if they fail the quantitative tests, we have to abandon them. This happens every day in science. If the idea has failed the test and knowing that the test 

was conducted with the best knowledge available at the time, scientists should not 

pretend or claim that their interesting ideas are still alive. Such interesting but 

unproven ideas belong to science fiction. During my testimony I showed that the 

continental arctic warming during 1970–2000 belongs to that category (Figure 2 of 

my testimony), too. Nothing is 100 percent certain in climatology, but I believe that 

the Senate subcommittee members did not want ‘noncommittal’ statements from the 

panel members. On the other hand, if the idea passes the test, I am happy to support the idea. Since I am not a climatologist, I have no hang-up in either camp. 

What I can say as an auroral physicist is that the present climatology is very abnormal. 

As you may know, the ‘‘mid-20th century jump’’ is a northern hemisphere phenomenon, not a southern hemisphere phenomenon. Thus, it is NOT A GLOBAL phenomenon. This is very clear in the paper by Jones, which became the basis of the 

IPCC Report. In fact, it appears to be a phenomenon above 40° latitude in the 

northern hemisphere, so that it is doubtful that it is really a global phenomenon. 

It may well be that this is why the GCMs cannot reproduce it as the greenhouse 

effect! (Just as is the case of the continental arctic warming!) 

Some people argue that the GCMs have not advanced enough to be used for such 

tests. If so, they would logically also have to doubt the basis of the Kyoto protocol 

on global warming. There may be some problems with prediction, because we have 

to assume the amount of CO2 released in the future. On the other hand, we are 

using GCMs for what we call ‘‘hind-casting’’ based on the observed CO2 data, and 

the GCMs are accurate enough for our purpose; furthermore, we are using 14 

GCMs. 

Question 7. You indicate on page 1 of your written testimony that ‘‘It is incorrect 

to conclude that the present warming in the Arctic is due entirely to the greenhouse 

effect caused by man.’’ In answer to a question, you indicated that such assertions 

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were being made mainly by the media and did not indicate any scientific assessments that were making this assertion. Is it your opinion, therefore, that we can 

rely on the IPCC and ACIA assessments, even though there may be some 

misimpressions given by some in the media, or are you suggesting that the assessments are also flawed? 

Question 7a. If the latter, please provide specific examples where you think the 

complete picture is not being presented. What part of the warming do you judge to 

be human-induced and what fraction natural, and what is your estimate of how this 

ratio has changed over time? 

Answers to Questions 7 and 7a. Both the IPCC and ACIA Reports served in raising awareness of the CO2 problem. However, I am not very happy about the ‘‘tactics’’ 

they used (you must have heard about some of the complaints from the contributors). There was no ‘‘refereeing’’ like scientific papers for scientific journals. During 

our testimony, Dr. Reiter was quite critical of one chapter on malaria, saying that 

the contents was very poor. You will recall that this was also a major complaint by 

Dr. Michael Crichton during his testimony in one of the earlier hearings. As I also 

mentioned in my testimony, the present climate research presented by the IPCC Report is not taking the normal scientific practice. For example, Mann’s ‘‘hockey stick’’ 

figure was so appealing for the purpose of raising awareness of the greenhouse effect, it was prominently used by the IPCC Reports. Mann’s figure shows neither the 

Medieval warming nor the Little Ice Age, so that some scientists questioned its accuracy. Finally, two Canadian experts in statistics analyzed the same data (which 

they said Mann was very reluctant to make available; as you may know, Congress 

finally demanded he submit the data) and showed that there is no ‘‘hockey stick’’ 

in the data (Figure I). I am afraid that Mann’s results, the IPCC ‘‘flagship,’’ may 

turn out to be a flawed case. Dr. Robert Correll used it in his testimony without 

telling us that there is some problem with it, even if he believes its accuracy. It is 

unfortunate that it gave the impression that the greenhouse effect did indeed take 

off. 

In science, new results should be scrutinized by the community, and if they survive the scrutiny, they become scientific facts. It is my belief that the IPCC way 

of mobilizing hundreds of scientists is not a good practice in science. I wonder how 

many of the IPCC contributors can defend Mann’s work, in spite of the fact that 

they are the co-authors. 


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Another important issue: as I testified, many climatologists use satellite data, 

which became available only in the 1970s, when the latest rise in temperature occurred. Therefore, what they report is naturally related to the temperature rise. 

Many of the presently active scientists were born in the 1960s and 1970s, so that 

it is natural for them to assume that the temperature rise has been happening during their whole life. However, in terms of genuine climatology, it is but an instant. 

That is why I want to call them ‘‘instant climatologists’’; many of them do not want 

to work on the mid-20th century jump, since it will take a great deal of effort to 

get data similar to what satellites can provide readily. In order to work on climatology, I am asking my colleagues that they should try to get at the very least data 

that spans a few hundreds years. Climatology used to be like anthropology. However, after the advent of satellites and computers, it has become an instant climatology. 

Now, the present problem is that the media and many special interest groups take 

the scientific data after the 1970s as scientific fact for the greenhouse effect. As soon 

as results associated with the rising temperature are reported in scientific papers 

(or even before), they are immediately reported by them as scientific facts proving 

the greenhouse effect, confusing the term global warming as synonymous with the 

greenhouse effect. Many media people do not have enough scientific background on 

the greenhouse effect. I might add that scientists who doubt or criticize greenhouse 

studies are demonized by the media these days. All this is a very abnormal circumstance in science, I am afraid. Whenever an issue is raised, the media defends 

itself by saying that hundreds of scientists joined in the preparation of the IPCC 

Reports. I hope you can understand the problem. 

Distinguishing between natural and manmade components of climate change is a 

very difficult task, but IARC scientists are challenging the problem, since this is the 

one way to ‘‘reduce uncertainty in climate change predictions’’; please see your item 

8. 

Question 8. In your Figure 7b (top) you include a linear trend line beginning in 

1760 and going to the year 2000. Why do you assume that human-induced influences should be linear, especially given the temporal and spatial variations in the 

forcing terms, interactions these might have for the atmospheric and oceanic circulations, etc.? 

Answer. The linear line in Figure C is NOT meant to be human-induced influence 

at all. It is only recently that the ice core (O18) analysis provided us with proxy 

data for the last 200 years. The longer the analysis period is, the more accurate the 

baseline becomes, on which various fluctuations are superposed. In the 100-year 

data (Figure A), we could not see clearly the linear trend (the ACIA Report, p. 23, 

used the 100-year average value as the baseline). There is little doubt about the 

presence of the linear trend in the 200-year data. 

As you correctly observed, there is no way to explain the linear trend by the 

greenhouse effect. I speculate that it is a natural change; the sea ice data and some 

other O18 data show similar linear trends. Are we still recovering from the Little 

Ice Age? 

IPCC Reports say that the global temperature increased by 0.6°C during the last 

century, and it implies that the increase is caused by the greenhouse effect. If the 

linear change continued until recently, and if it were indeed to be natural change, 

the greenhouse effect will not be a large fraction of the 0.6°C. This is the uncertainty we have to face in climate change research at the present time. We have to 

isolate the linear trend and other natural changes in detail and find out the real 

contribution of the greenhouse effect. 

Question 8a. Might it be that conditions continue in one state for a while and then 

flip, for example, once the ice melt reaches a certain amount or once temperatures 

in key regions exceed the freezing point? 

Answer. What you are referring to may be what we call the ‘‘threshold’’ point. For 

example, many researchers told me earlier that sea ice in the Arctic Ocean off the 

Alaskan coast had crossed ‘‘the point of no-return’’ during the summer months based 

on satellite data. However, sea ice was much closer to the Alaskan coast in 2005 

than in 2004 or 2003. It came back last year. 

In principle, what you say may occur; however, I am not sure if the present climatology can predict accurately the threshold point of any climate change phenomena. 

Question 9. Although climate models may not provide sufficiently accurate representations of the spatial distribution of warming, do you agree that they do include representations of the overall thermodynamic and dynamic influences, so that 

the global integral of the influence, which is presumably based on the overall balance of energy, of increasing concentrations of greenhouse gases, and of other facVerDate Nov 24 2008 14:34 Feb 07, 2011 Jkt 064226 PO 00000 Frm 00113 Fmt 6601 Sfmt 6621 S:\GPO\DOCS\64226.TXT SCOM1 PsN: JACKIE
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tors is roughly correct? What improvements do you think are most needed in the 

available climate models? 

Answer. The physics of the greenhouse effect is sound and clear; that is not the 

question. The questions are: (1) how much did the greenhouse effect contribute to 

the 0.6°C increase and the mid-20th century jump, and (2) how much will the temperature increase by 2100, more than 6°C or less than 1°C? (When I say this, some 

scientists immediately argue with me and say that I deny the greenhouse effect. 

They forget the normal scientific practice, and the IPCC must have created such an 

unscientific atmosphere.) 

At the International Arctic Research Center (IARC), our main objective is to ‘‘reduce uncertainty in future climate change predictions.’’ Certainly, our progress in 

science will improve the modeling effort. On the other hand, we should not forget 

that the Earth’s temperature fluctuates all the time. We cannot understand the 

cause(s) of the Big Ice Age, the Medieval warming (1000–1300 AD, almost as warm 

as the present time), and the Little Ice Age (1400–1900?), in addition to the fact 

that the temperature was higher at the beginning of the present interglacial period 

and some other interglacial periods when only anthropoids were present on Earth. 

This is what Dr. Thomas was stressing during his testimony. There is no reason 

to assume that the linear change suddenly stopped after 1900. We have to identify 

and subtract natural change from the on-going changes; the rest will give us some 

idea about the greenhouse effect. 

I am afraid that this communication is getting too heavy, so that I have put two 

cartoons at the end. I find that cartoonists observe well the present situation. 

Æ 


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