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GEOENGINEERING: 

INNOVATION, RESEARCH, AND TECHNOLOGY 

JOINT HEARING 

BEFORE THE

SUBCOMMITTEE ON ENVIRONMENT & 

SUBCOMMITTEE ON ENERGY 

COMMITTEE ON SCIENCE, SPACE, AND 

TECHNOLOGY 

HOUSE OF REPRESENTATIVES 

ONE HUNDRED FIFTEENTH CONGRESS 

FIRST SESSION 

NOVEMBER 8, 2017 

Serial No. 115–36 

Printed for the use of the Committee on Science, Space, and Technology 

( 

Available via the World Wide Web: http://science.house.gov 
(II) 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY 

HON. LAMAR S. SMITH, Texas, Chair 

FRANK D. LUCAS, Oklahoma 

DANA ROHRABACHER, California 

MO BROOKS, Alabama 

RANDY HULTGREN, Illinois 

BILL POSEY, Florida 

THOMAS MASSIE, Kentucky 

JIM BRIDENSTINE, Oklahoma 

RANDY K. WEBER, Texas 

STEPHEN KNIGHT, California 

BRIAN BABIN, Texas 

BARBARA COMSTOCK, Virginia 

BARRY LOUDERMILK, Georgia 

RALPH LEE ABRAHAM, Louisiana 

DRAIN LAHOOD, Illinois 

DANIEL WEBSTER, Florida 

JIM BANKS, Indiana 

ANDY BIGGS, Arizona 

ROGER W. MARSHALL, Kansas 

NEAL P. DUNN, Florida 

CLAY HIGGINS, Louisiana 

RALPH NORMAN, South Carolina 

EDDIE BERNICE JOHNSON, Texas 

ZOE LOFGREN, California 

DANIEL LIPINSKI, Illinois 

SUZANNE BONAMICI, Oregon 

AMI BERA, California 

ELIZABETH H. ESTY, Connecticut 

MARC A. VEASEY, Texas 

DONALD S. BEYER, JR., Virginia 

JACKY ROSEN, Nevada 

JERRY MCNERNEY, California 

ED PERLMUTTER, Colorado 

PAUL TONKO, New York 

BILL FOSTER, Illinois 

MARK TAKANO, California 

COLLEEN HANABUSA, Hawaii 

CHARLIE CRIST, Florida 

SUBCOMMITTEE ON ENVIRONMENT

HON. ANDY BIGGS, Arizona, Chair 

DANA ROHRABACHER, California 

BILL POSEY, Florida 

MO BROOKS, Alabama 

RANDY K. WEBER, Texas 

BRIAN BABIN, Texas 

BARRY LOUDERMILK, Georgia 

JIM BANKS, Indiana 

CLAY HIGGINS, Louisiana 

RALPH NORMAN, South Carolina 

LAMAR S. SMITH, Texas 

SUZANNE BONAMICI, Oregon, Ranking 

Member 

COLLEEN HANABUSA, Hawaii 

CHARLIE CRIST, Florida 

EDDIE BERNICE JOHNSON, Texas 

SUBCOMMITTEE ON ENERGY

HON. RANDY K. WEBER, Texas, Chair 

DANA ROHRABACHER, California 

FRANK D. LUCAS, Oklahoma 

MO BROOKS, Alabama 

RANDY HULTGREN, Illinois 

THOMAS MASSIE, Kentucky 

JIM BRIDENSTINE, Oklahoma 

STEPHEN KNIGHT, California, Vice Chair 

DRAIN LAHOOD, Illinois 

DANIEL WEBSTER, Florida 

NEAL P. DUNN, Florida 

LAMAR S. SMITH, Texas 

MARC A. VEASEY, Texas, Ranking Member 

ZOE LOFGREN, California 

DANIEL LIPINSKI, Illinois 

JACKY ROSEN, Nevada 

JERRY MCNERNEY, California 

PAUL TONKO, New York 

BILL FOSTER, Illinois 

MARK TAKANO, California 

EDDIE BERNICE JOHNSON, Texas 
(III) 

C O N T E N T S 

November 8, 2017 

Page 

Witness List ............................................................................................................. 2 

Hearing Charter ...................................................................................................... 3 

Opening Statements 

Statement by Representative Andy Biggs, Chairman, Subcommittee on Environment, Committee on Science, Space, and Technology, U.S. House of 

Representatives .................................................................................................... 4 

Written Statement ............................................................................................ 5 

Statement by Representative Suzanne Bonamici, Ranking Member, Subcommittee on Environment, Committee on Science, Space, and Technology, 

U.S. House of Representatives ............................................................................ 7 

Written Statement ............................................................................................ 9 

Statement by Representative Lamar S. Smith, Chairman, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 11 

Written Statement ............................................................................................ 13 

Statement by Representative Randy K. Weber, Chairman, Subcommittee on 

Energy, Committee on Science, Space, and Technology, U.S. House of Representatives ........................................................................................................... 15 

Written Statement ............................................................................................ 17 

Statement by Representative Marc A. Veasey, Ranking Member, Subcommittee on Energy, Committee on Science, Space, and Technology, U.S. 

House of Representatives .................................................................................... 19 

Written Statement ............................................................................................ 21 

Witnesses: 

Dr. Phil Rasch, Chief Scientist for Climate Science, Laboratory Fellow, Pacific 

Northwest National Laboratory 

Oral Statement ................................................................................................. 23 

Written Statement ............................................................................................ 26 

Dr. Joseph Majkut, Director of Climate Policy, Niskanen Center 

Oral Statement ................................................................................................. 45 

Written Statement ............................................................................................ 47 

Dr. Douglas MacMartin, Senior Research Associate, Cornell University 

Oral Statement ................................................................................................. 57 

Written Statement ............................................................................................ 59 

Ms. Kelly Wanser, Principal Director, Marine Cloud Brightening Project, 

Joint Institute for the Study of the Atmosphere and Ocean, University 

of Washington 

Oral Statement ................................................................................................. 72 

Written Statement ............................................................................................ 74 

Discussion ................................................................................................................. 89 

Appendix I: Additional Material for the Record 

Statement submitted by Representative Eddie Bernice Johnson, Ranking 

Member, Committee on Science, Space, and Technology, U.S. House of 

Representatives .................................................................................................... 106 
Page

IV 

Letter submitted by Representative Suzanne Bonamici, Ranking Member, 

Subcommittee on Environment, Committee on Science, Space, and Technology, U.S. House of Representatives ............................................................... 107 

Statement submitted by Mr. Floyd DesChamps, President, The Desner Group, 

LLC ........................................................................................................................ 111
(1) 

GEOENGINEERING: 

INNOVATION, RESEARCH, AND TECHNOLOGY 

Wednesday, November 8, 2017 

HOUSE OF REPRESENTATIVES, 

SUBCOMMITTEE ON ENVIRONMENT AND

SUBCOMMITTEE ON ENERGY, 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY, 

Washington, D.C. 

The Subcommittees met, pursuant to call, at 10:11 a.m., in Room 

2318 of the Rayburn House Office Building, Hon. Andy Biggs 

[Chairman of the Subcommittee on Environment] presiding. 
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Chairman BIGGS. The Committee on Science, Space, and Technology Subcommittee on Environment and Subcommittee on Energy joint hearing on Geoengineering: Innovation, Research and 

Technology is called to order. 

Without objection, the Chair is authorized to declare recesses of 

the Subcommittee at any time, and I now recognize myself for five 

minutes for an opening statement. 

Good morning, and welcome to the joint Environment Subcommittee and Energy Subcommittee hearing on geoengineering. I 

thank each of our witnesses for being here today. 

Since this is the first time we’re discussing the topic of 

geoengineering this Congress, it is important to explain what 

geoengineering actually is. In its simplest terms, geoengineering is 

the concept of using scientific understanding to alter the atmosphere in a way that produces positive outcomes and results. Many 

of the concepts in this field deal with solar radiation management, 

or how to influence the effects of the sun on the earth. 

But the field is by no means limited to solar research. 

Geoengineering can also be used to manipulate different levels of 

gases in the atmosphere, such as carbon dioxide. These avenues of 

geoengineering research and others are still in the developmental 

stage, and any or all of them may warrant further exploration. 

While there are at least a few programs in our Nation’s universities that are looking into these concepts, federal research is still 

limited. However, if in the future the government wants to actually 

apply the concepts and findings of geoengineering research, we 

must fully examine both the potential merits and potential pitfalls 

of this emergent field. 

Since the theories and concepts involved are still so new, we cannot say definitively if geoengineering technology warrants full-scale 

development or deployment. Quite simply, more basic research is 

necessary to determine whether it is a viable tool. 

Today, we will learn about what research has been conducted on 

geoengineering and which promising concepts should be explored 

further. We will hear from government, academia, think tank and 

industry representatives who have unique perspectives on this 

topic. They will tell us about the research being done, as well as 

future concepts and how they could be used responsibly. 

We as lawmakers have a responsibility to explore these concepts, 

learn as much as possible about them, and discuss ideas about how 

we can be helpful in supporting basic research. 

I’d also like to take a moment to clarify any mischaracterizations 

about this hearing. The purpose of this hearing is to discuss the 

viability of geoengineering and any early-stage research associated 

with this approach. The hearing is not a platform to further the debate about climate change. We’ve had lots of that this session. Instead, its aim is to explore approaches and technologies that have 

been discussed in the scientific community and to assess the basic 

research needed to better understand the merits of these ideas. It 

is my hope that members will respect this focus so that we can 

have a meaningful discussion about geoengineering. 

Again, I want to thank the witnesses for being here today, and 

I look forward to hearing more about these interesting concepts. 

[The prepared statement of Chairman Biggs follows:] 
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Chairman BIGGS. With that, I yield back my time and recognize 

the Ranking Member, Ms. Bonamici for her opening statement. 

Ms. BONAMICI. Thank you very much, Mr. Chairman, and thank 

you for holding this important hearing. 

I’m very encouraged that the Science Committee is discussing 

geoengineering, a field of science and engineering that is still in its 

infancy and has ample areas for future research, and it’s noteworthy for its potential. It’s important that we consider it from political, ethical, legal, and environmental perspectives. 

Geoengineering is a set of climate interventions that aim to manipulate our climate to either remove greenhouse gases from our 

atmosphere or reduce the amount of sunlight absorbed by the 

Earth. Now, some may argue that geoengineering is a way to use 

technology to bypass important mitigation and adaptation strategies that address the impacts of climate change, but even with 

geoengineering, our first and primary actions to address climate 

change must be mitigation and adaptation strategies. 

In our communities, climate change is not a partisan issue. Nationwide, there are fishers and farmers and small-business owners, 

and servicemen and women who are having to change the way they 

do their jobs because of climate change, and regardless of their political affiliation. The economic, health, and environmental consequences of climate change are well known, and our understanding about how to address the causes of climate change continue to improve. 

It’s critical that we support scientific research about climate, and 

that we build on rather than break down decades worth of progress 

on this issue. I urge the Committee to hold hearings specifically on 

mitigation and adaption strategies to help communities grapple 

with this situation. 

Geoengineering is an option our country should explore. The 

state of current geoengineering research makes clear that we are 

years or perhaps decades away from potential deployment, and the 

risks of deployment are not well understood, and we’re hoping for 

some answers here today. In fact, a key finding in the U.S. Global 

Change Research Program’s Climate Science Special Report, which 

was published last Friday, determined that further assessments of 

the technical feasibilities, costs, risks, co-benefits, and governance 

challenges of climate intervention or geoengineering strategies, 

which are as yet unproven at scale, are a necessary step before 

judgments about the benefits and risks of these approaches can be 

made with high confidence. 

This is because of a lack of technical maturity and understanding 

of the risks associated with geoengineering. We do not currently 

have enough evidence to determine whether any of the various proposals for geoengineering can provide long-term solutions to address the impacts of climate change, or that they would not pose 

any adverse consequences to our environment. 

Our climate is changing, and the warming trends observed over 

the last hundred years are primarily caused by human activities, 

specifically the emission of greenhouse gases. In fact, this is one of 

the most prominent findings in the Climate Science Special Report. 

This report unequivocally lays out the need to reduce carbon diox-
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ide emissions to prevent long-term warming and short-term climate 

change. 

I want to ask the Subcommittee Chairman for unanimous consent to include a letter addressed to him and Chairman Smith into 

the record. It’s been signed by many prominent members of the 

geoengineering research community, highlighting the urgency of 

the threat that climate change poses and reemphasizes that 

geoengineering is not a magic fix to addressing climate change. 

Chairman BIGGS. Without objection. 

[The information appears in Appendix I] 

Ms. BONAMICI. And with that, Mr. Chairman, I’d like to yield the 

remainder of my time to the gentleman from California, Mr. 

McNerney. 

[The prepared statement of Ms. Bonamici follows:] 
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Chairman BIGGS. Mr. McNerney, please. 

Mr. MCNERNEY. Well, I thank the gentlewoman from Oregon, 

and I thank the Chairman for calling this hearing. 

Climate change is happening, and the effects are accelerating 

faster than the scientific models predict. The changes we are experiencing today are the results of heating that has taken place over 

the past decades. Meanwhile, carbon concentration in the atmosphere is continuing to increase. Therefore, additional heating and 

climate impacts are inevitable even if we were to stop carbon emissions immediately. In other words, we are committed to significant 

change. 

The unknown is how much change we’re committed to and how 

fast it will take place. It’s not known if we are committed to truly 

catastrophic change with the current policies or not. But no matter 

what, it’s absolutely critical to reduce carbon emissions and prepare for the changes that are coming, in other words, mitigate and 

adopt. 

The changes we are committed to may be so strong that we’ll 

need to know what can be done to prevent utter catastrophe. What 

tools are available? What are the technical feasibilities? What are 

the costs and what are the risks of the different approaches to 

avoiding catastrophic change? 

That’s where this hearing comes in. What are the hypothetical 

alternatives and how do we best go about determining their feasibility, costs, and impacts? 

I will be dropping a bill next week, which members of the panel 

have already seen, and I need guidance from experts on what 

changes to the proposed legislation is needed. 

Thank you, I yield back. 

Chairman BIGGS. Thank you. 

I now recognize the Chairman of the entire Committee, Chairman Smith. 

Chairman SMITH. Thank you, Mr. Chairman, and I also thank 

Congressman Weber for letting give my opening statement before 

him. I have a markup that began in the Judiciary Committee that 

unfortunately I’ve got to attend but I hope to be back shortly. 

Mr. Chairman, first I want to thank the Chairman of the Environment Subcommittee, you, for having this hearing, and also Representative Weber of Texas, the Chairman of the Energy Subcommittee, for your interest in this subject. I also want to thank 

the gentleman from California, Mr. McNerney, for his persistent interest in this subject. Every time I’ve seen him on the House Floor 

for the last couple of months, he’s wanted to have this hearing, so 

we appreciate his interest as well. 

Mr. Chairman, geoengineering’s potential is worth exploring. 

Generally, we know that the technologies associated with 

geoengineering could have positive effects on the Earth’s atmosphere. These innovations could help reduce global temperatures or 

pull excess greenhouse gases out of the atmosphere. 

For instance, one of the most intriguing ideas in this field is 

solar radiation management. This concept involves finding innovative strategies to reduce the amount of sunlight that reaches and 

warms the earth. Today, one of our witnesses will expand on this 

idea with a concept that brightens clouds and reflects sunlight, 
12 

which is measured in albedo. While this technology is interesting, 

we have a lot to learn. 

Some have questioned the unintended consequences of 

geoengineering. One concern is that brightening clouds could alter 

rain patterns, making it rain more in some places or less in others. 

Such technologies could drastically reduce global temperatures in 

the future by spraying aerosols into the atmosphere to reflect sunlight. While we are not sure this is plausible, some scientists believe it could achieve substantial environmental benefits at a 

cheaper cost than regulations. 

Regardless of these claims, we still do not know enough about 

this subject to thoroughly understand the pros and cons of these 

types of technologies. 

As the climate continues to change, geoengineering could become 

a tool to curb resulting impacts. Instead of forcing unworkable and 

costly government mandates on the American people, we should 

look to technology and innovation to lead the way to address climate change. 

Geoengineering should be considered when discussing technological advances to protect the environment, and geoengineering 

should not be ignored before we have an opportunity to discover its 

potential. This hearing will help Congress do just that. 

Mr. Chairman, I thank our witnesses today for testifying on the 

current state of geoengineering research and for their recommendations about how to advance practicable efforts in this area, and I’ll 

yield back. 

[The prepared statement of Chairman Smith follows:] 
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Chairman BIGGS. Thank you, Mr. Chairman. 

I now recognize the Chairman of the Energy Subcommittee, Mr. 

Weber, for an opening statement. 

Mr. WEBER. Thank you, Mr. Chairman. Let me add my welcome 

to today’s joint Environment and Energy Subcommittee. 

Good morning and welcome to today’s Joint Environment and 

Energy Subcommittee hearing. Today, we are going to hear from 

a panel of experts on the status of America’s research in 

geoengineering, a field truly in the scientific unknown. Hearings 

like today’s help remind us of the Science Committee’s core focus: 

the basic research that provides the foundation for technology 

breakthroughs. 

Within the DOE lab system, Pacific Northwest National Lab is 

leading the effort to protect—to explore the potential impact of 

geoengineering technology. PNNL hosts geoengineering researchers 

who hope to open the dialog on this groundbreaking technology— 

Jerry, you’ll be glad to hear—and consider what methods could 

have the most positive impact on the climate. Some proposed ideas 

at PNNL include placement of mirrors in space, injection of naturally occurring substances into the atmosphere to mimic a volcanic 

eruption, or brightening the clouds overhead. All of these methods 

could have a cooling effect on our lower atmosphere. 

It’s amazing to think that molten lava from volcanic eruptions 

can actually produce compounds that cool the air. Brightening 

clouds is equally interesting, but only early-stage evaluation has 

occurred on the practicality of this approach. As we will hear from 

one of our witnesses, we have already seen ship tracks that create 

this brightening effect, where the sunlight is reflected back into the 

atmosphere. By injecting aerosols composed of seawater particles 

into low ocean clouds, researchers could shrink the size of water 

droplets and in turn brighten those clouds. 

PNNL’s Climate and Earth Systems Science researchers and 

partnerships have to rely on computer models to understand the 

potential impact of these very basic geoengineering methods, but as 

we’ve heard before in this Committee, models are only as good as 

the data they use. 

I believe that we should consider funding appropriately scaled 

field-testing to improve the accuracy of geoengineering models. 

Through the National Labs, the United States already partners 

with researchers from Canada, China, Denmark, Germany, Japan, 

and Norway. These scientists used the output from 12 climate models in the Geoengineering Model Intercomparison Project, which 

seek to understand the possible climate effects of geoengineering. 

Geoengineering has the potential to provide us with a whole new 

understanding and approach to atmospheric research. If we put 

aside the debates about climate change, we can support innovations in science that can create a better prospect for future generations. 

The Federal Government should prioritize this kind of basic research so we can not only understand the science of 

geoengineering, but hopefully partner with the private sector to develop technology to mitigate changes in climate. When the government supports basic research, everyone has the opportunity to ac-
16 

cess the fundamental knowledge that can lead to the development 

of future technologies. 

The future’s bright for geoengineering, and I want to thank our 

panel of witnesses for testifying today. I look forward to a productive discussion about the innovation, research and technology of 

this emerging field of science. 

Mr. Chairman, I yield back. 

[The prepared statement of Mr. Weber follows:] 
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Chairman BIGGS. Thank you, Mr. Weber. 

I now recognize the Ranking Member of the Energy Subcommittee, Mr. Veasey, for an opening statement. 

Mr. VEASEY. Thank you, Mr. Chairman, and we have an excellent panel of witnesses today and I’m really looking forward to 

hearing their insights, and thank you very much for being here. 

Despite the numerous claims, geoengineering is not the answer 

to 150 years of polluting our planet at an unsustainable rate, and 

in order to slow the impact of climate change and eventually reverse its effects, we have to get out priorities straight, and mitigation and adaptation must be part of the top priorities. We must 

face the global challenge of climate change, and solving this challenge requires every nation to find effective solutions to reduce our 

emissions and set us on a far more sustainable path. 

The scientific community has made clear that climate change will 

continue to be an issue for the rest of this century and beyond. The 

long-term nature of this challenge is the reason we need to investigate every possible solution in addition to implementing mitigation and adaptation strategies. 

Geoengineering, in particular, is in its very early stages and 

more research is required to expand our understanding of its risks 

and potential benefits. During our discussion today, I hope the witnesses can provide us with their recommendations on what types 

of research the Federal Government should invest in for the benefit 

of all Americans. These recommendations will help shape our national investments in climate modeling, Earth systems research, 

laboratory experiments, and potential small-scale field tests in the 

coming decades. 

On that note, I would like to stress to my colleagues the importance of supporting the full spectrum of research at the Department of Energy. In particular, activities within the Office of 

Science’s Biological and Environmental Research program are crucial to expanding our knowledge of Earth systems and climate modeling. Funding this important research can have numerous benefits, including advancing the field we are discussing today. 

It is unfortunate that the Trump Administration’s budget proposal included a 43 percent cut to BER with major cuts and outright eliminations of key activities within the Earth and Environmental Systems subprogram. These cuts would hurt the emerging 

field of geoengineering, but more importantly, they would cripple 

our ability to understand the range of factors driving global temperatures upward. If you are a climate skeptic, then you must support more research to expand our collective understanding. If you 

cannot support that, then you are choosing to ignore the facts. 

Frankly, we have no time to ignore the mounting scientific evidence as it relates to climate change. We need productive dialogue 

if we want to better understand this challenge and embrace the 

necessary solutions. 

In addition to supporting the key research activities that underpin geoengineering, there may also be additional federal investments that Congress should consider in order to have an impact in 

the near future. Carbon dioxide removal strategies are a generally 

less-risky form of climate intervention that may prove useful in our 

efforts to fight the impacts of climate change. These strategies 
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come in the form of bioenergy with carbon capture and sequestration, direct air capture technologies, enhanced geological weathering, and land use management, just to name a few. 

The National Academies examined carbon dioxide removal in 

2015 and concluded that this area is ripe for further federal research investments. For this reason, I included this critical research in a draft bill that I will be introducing in the coming 

weeks: the Fossil Energy Research and Development Act. In addition to authorizing key R&D activities for carbon capture, utilization, and sequestration activities, the bill would also instruct DOE 

to create a research program on carbon dioxide removal. I hope 

that my of my colleagues on both sides of the aisle will join me as 

a cosponsor of this legislation. The bill would push the DOE to 

prioritize the important work of environmental mitigation within 

the Office of Fossil Energy. The public health and economic benefits are considerably numerous. I hope this bill can be a bipartisan 

path forward to an area of research at DOE that needs it. 

I look forward to working with my colleagues on these issues, 

and thank you, Mr. Chairman. I yield back the balance of my time. 

[The prepared statement of Mr. Veasey follows:] 
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Chairman BIGGS. Thank you, Mr. Veasey. 

Let me introduce our witnesses. Our first witness today is Dr. 

Phil Rasch, Chief Scientist for Climate Science and Laboratory Fellow at Pacific Northwest National Laboratory. Previously, Dr. 

Rasch served as a Chair of the International Global Atmospheric 

Chemistry program and was named a Fellow of the American Association for the Advancement of Science. He received a bachelor’s degree in atmospheric science and chemistry from the University of 

Washington and a master’s of science in meteorology from Florida 

State University, and he completed his Ph.D. at the National Center for Atmospheric Research in Boulder, Colorado. 

Our second witness is Dr. Joseph Majkut, Director of Climate 

Policy at Niskanen Center. Previously, Dr. Majkut worked as a 

Congressional Science Fellow under the American Association for 

the Advancement of Science and the American Geoscience Institute. Dr. Majkut received degrees from Princeton University, the 

Delft University of Technology, and Harvey Mudd College. 

Our next witness is Dr. Douglas MacMartin, Senior Research Associate at Cornell University. Previously, Dr. MacMartin led the 

Active Control and Flow Control Research programs at the United 

Technologies Research Center. He received his bachelor’s degree 

from the University of Toronto and his Ph.D. in aeronautics and 

astronautics from MIT. 

And our last today is Ms. Kelly Wanser, Principal Director at 

Marine Cloud Brightening Project, Joint Institute for the Study of 

the Atmosphere and Ocean at the University of Washington. Ms. 

Wanser is a Member of the National Academies of Sciences. She received her bachelor’s degree from Boston College and her master’s 

degree from the University of Oxford. 

I now recognize Dr. Rasch for five minutes to present—— 

Dr. RASCH. Are we ready? 

Chairman BIGGS. We’re going to keep discussing her for a few 

minutes. No, I think we’re now ready to recognize Dr. Rasch for 

five minutes to present his testimony. Thank you, Dr. Rasch. 

TESTIMONY OF DR. PHIL RASCH, 

CHIEF SCIENTIST FOR CLIMATE SCIENCE, 

LABORATORY FELLOW, 

PACIFIC NORTHWEST NATIONAL LABORATORY 

Dr. RASCH. Thank you. Chairmen Biggs and Weber and Smith, 

Members Bonamici and Veasey and Subcommittee Members, 

thanks for the opportunity to be here. 

I testified before this Committee in 2010 on geoengineering. I’m 

the Chief Scientist for Climate Science at Pacific Northwest National Labs, where I lead programs studying Earth’s atmosphere 

and environmental change. I’ve also been involved in 

geoengineering research. I’ve authored about 20 papers on 

geoengineering, supported mainly by philanthropic foundations and 

the NSF in my previous job. I was also a member of the committee 

that wrote the National Research Council report on geoengineering, 

and a lead author on relevant chapters from the Intergovernmental 

Panel on Climate Change report as well. 

Americans have become increasingly aware of changes in our environment ranging from dramatic decreases in sea ice in the arctic 
24 

to increases in summertime heat waves, droughts, floods, fires, and 

damage from hurricane and other extreme weather events including increasing ocean acidity that damages fisheries. 

Evidence in the National Climate Assessment and elsewhere indicates that the changes are connected to increases in carbon dioxide so a prudent step to reducing impacts is to stop increasing carbon dioxide as quickly as possible. 

Two engineering methods attempt to address some of these 

threats through two very different strategies. I’m not an expert in 

the carbon dioxide removal strategy you heard about earlier so I 

won’t discuss it further, and I’ll sometimes talk about solar radiation management as sunlight reflect methods, a term I prefer. 

Sunlight reflection methods try to reflect some of the sun’s energy back to space, cooling the planet. Two strategies have received 

the most attention so I’ll focus on those. One method is called marine cloud brightening. You’ll all have felt the surface temperature 

go down when a cloud passes overhead on a hot summer day by 

reflecting sunlight back to space. This is how clouds cool the planet. We know clouds can be further brightened. One dramatic example occurs when ocean freighters add particles below clouds to 

change them and form bright ship tracks. Marine cloud brightening 

attempts to mimic that kind of cooling by introducing sea salt particles below clouds. Stratospheric aerosol geoengineering tries to 

mimic the cooling effects of large volcanic eruptions by placing 

extra particles in the upper atmosphere. 

Let me just cover a bit of what we know and don’t know and 

then make some recommendations for progress. There’s a lot more 

detail in my written testimony. We know it’s still early days for 

SRM research but there are hints it could help address climate 

change by offsetting, delaying or slowing warming. Hints are, that 

help counter other changes as well. We think SRM could buy time 

for other measures to be put in place. Even if it works, though, we 

know it won’t be a magic bullet. It won’t compensate for all problems, and it may have side effects. Stratospheric aerosol 

geoengineering and marine cloud brightening have some common 

features but they’re different with different risks and impacts to 

the planet. 

If we used geoengineering, it would need to be adjusted to balance the excess carbon in the atmosphere, and we think it would 

be very risky to balance a lot of carbon dioxide. 

We don’t yet know whether geoengineering should be a part of 

the strategies addressing climate change. It’ll take at least a decade to sort out the benefits, risks, and tradeoffs associated with 

these different technologies. 

So what should we do? I think it’s time for a coherent and goaloriented geoengineering research program that complements ongoing research in Earth systems science but focuses on a defined set 

of objectives targeting better understanding of the effectiveness and 

potential risks associated with specific geoengineering techniques. 

That program should include modeling, lab studies, small-scale 

field studies, and technology development in addition to addressing 

societal needs for transparency in governance. 

Small-scale field studies are needed. These studies should be far 

too small to affect climate but they’ll help us understand the proc-
25 

esses important to the SRM strategies, and also help answer crucial questions for climate science. I discuss one example in my written testimony. I believe it’s urgent to have a review on governance 

strategy for this program to help with public understanding and 

engagement and to improve safety. 

Thanks, and I’m happy to take questions. 

[The prepared statement of Dr. Rasch follows:] 
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Chairman BIGGS. Thank you, Dr. Rasch. 

Now I’ll recognize Dr. Majkut for five minutes to present his testimony. 

TESTIMONY OF DR. JOSEPH MAJKUT, 

DIRECTOR OF CLIMATE POLICY, 

NISKANEN CENTER 

Dr. MAJKUT. Thank you, Chairmen Biggs and Weber, and Ranking Member Bonamici, and Members of the Committee. I’m grateful for the invitation to join you today. 

My name is Joseph Majkut, and I’m the Director of Climate Policy at the Niskanen Center here in Washington, D.C., where my 

work focuses on research in climate energy issues, and my personal 

area of expertise is climate science. 

There is no practical scientific doubt that human activity is contributing to climate change nor that continuing emissions will lead 

to more warming. There is, however, a great deal of uncertainty 

about the extent of future warming and its environmental and economic consequences. Given that uncertainty, we should think about 

this as a risk management problem. There may be no perfect solution but in general we should seek ways to reduce greenhouse gas 

emissions, minimize societal vulnerability, and otherwise limit the 

potential costs of a warming planet. 

Geoengineering may be one such tool to address those potential 

costs. Further research judiciously done will help us answer that 

question. With that in mind, I would like to emphasize three points 

from my written testimony. 

The first is that there is a great deal of uncertainty about whether or not geoengineering would work in practice. By changing the 

reflectivity of the high atmosphere or brightening clouds, we might 

be able to offset some degree of global warming quickly and reduce 

its attendant effects but the risk of unintended consequences might 

be large. 

We do know that once we start cooling the planet by artificial 

means, stopping will be followed by rapid warming as long as CO2

levels remain high. We also know that a geoengineered world could 

not simultaneously hold temperatures, rainfall and weather patterns static, meaning that there will be tradeoffs should engineering ever be used to partially or completely offset global warming. 

The second is the developing a better scientific understanding of 

those potential tradeoffs justifies ongoing and future research. 

Whether or not each of us is concerned about the risks of climate 

change or repulsed by the very idea of geoengineering, changes to 

the Earth’s climate will inevitably force future generations to confront such choices. This research will be affordable and need not 

supplant other efforts to understand the nature of climate change. 

Such research will occur in supercomputing facilities, at the lab 

bench, and also in small-scale field experiments. 

I’ll add that I hope it will also be approached via the social 

sciences as judgments of whether geoengineering is good or practical are not consigned to questions of chemistry or physics. Both 

the 2015 report from the National Research Council and the most 

recent update of the U.S. Global Change Research Program’s strategic plan highlight the importance of this research and com-
46 

plementary observational and theoretical work in climate science, 

especially since other countries or private actors might start intervention experiments of their own. 

Lastly, Congress should consider what regulatory governing 

structure will maximize innovation and scientific progress while 

protecting the public and environment from ill-informed experiments or premature deployment of these technologies. Under the 

1971 Weather Modification Act, experiments intent on altering the 

weather or planetary albedo are already regulated, and those regulations currently require that researchers report their activities to 

NOAA before and after working in the field. 

For today, that is enough. No one to our knowledge is set on 

large experiments in the near future. However, regulatory governance should grow as experiments grow larger, and it is not clear 

at present how such regulations might look. 

Our research at the Niskanen Center indicates that small-scale 

experiments should be subject to little more than reporting requirements and existing environmental protections because their climatological effect will be vanishingly small. However, Congress 

may want to consider if intermediate scale experiments should be 

subject to prior approval of an agency, and if large-scale experiments subject to the express permission of Congress itself. How we 

define small, medium and large is a question that will require further thought and should involve the input of the scientific community and civil society. A well-defined and stable regulatory structure will publicly clarify research progress and intent, and that intent should be to clarify the questions of how geoengineering might 

work and what the costs and benefits of doing it may be. That information could be used by future policymakers to avert trillions of 

dollars in losses. 

If the worst-case scenarios of global warming come to pass, these 

technologies could be used to help people, savings lives and economies from the most severe effects of climate change. Even if emissions reductions happen quickly, future generations may still find 

limited geoengineering of use. Managing the risks of climate 

change is not easy but it will be an ever-present task in the 21st 

century and beyond. Research into these technologies is an important part of that task as are adapting to warming and reducing 

emissions. A sturdy whip and a well-plotted course are no substitute for a close watch on the waters ahead nor lifeboats if we 

need them. 

Thank you for the opportunity to speak to you, and I look forward to your questions. 

[The prepared statement of Dr. Majkut follows:] 
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Chairman BIGGS. Thank you, Dr. Majkut, and I apologize for 

mispronouncing your name earlier. I apologize. 

I now recognize Dr. MacMartin for five minutes to present his 

testimony. 

TESTIMONY OF DR. DOUGLAS MACMARTIN, 

SENIOR RESEARCH ASSOCIATE, 

CORNELL UNIVERSITY 

Dr. MACMARTIN. Thank you. So I want to start by thanking the 

Committee Members for the opportunity to testify today. So I’m 

Douglas MacMartin at Cornell University with a background in 

both engineering and climate science, and I’ve been working on 

geoengineering for about the last ten years, and I think one of the 

striking things about this panel is actually how broad our agreement is likely to be on almost all of the issues. 

So the reason we’re all here of course is that as was reaffirmed 

last week by the U.S. National Climate Assessment, we know that 

the Earth’s climate is changing as a direct result of human emissions of greenhouse gases, and we know that the United States is 

already experiencing some impacts as a result. While these impacts 

may be manageable today, they will continue to grow so long as we 

continue to emit greenhouse gases, and so the less we emit, the 

lower the risk, and nothing we say here today about 

geoengineering changes the fact that we must reduce our greenhouse gas emissions and that this effort remains the most important component of a strategy to respond to climate change. 

That said, geoengineering approaches could become a valuable 

additional component of an integrated strategy to manage climate 

impacts. So carbon dioxide removal can effectively produce negative 

emissions, but we need research there on scalability, costs, and 

local impacts, and I’ll focus primarily on the sunlight reflection, or 

solar geoengineering side, so ideas like adding aerosols to the stratosphere or making marine boundary layer clouds more reflective, 

and I’d say from the limited modeling research that we’ve done to 

date, it’s plausible that a limited amount of solar geoengineering, 

used in addition to cutting emissions could reduce some of the impacts of climate change but there’s still considerable uncertainty 

into the side effects and risks, and that will require focused, goaloriented research. That could take decades, at least a decade, 

maybe more, which is why it’s important to start it soon. 

So it’s important to stress at the outset that solar geoengineering 

cannot be a substitute for cutting emissions for several reasons. 

This conclusion has been reached by every assessment of this technology including by the National Academies in 2015, so first it does 

not compensate all of the impacts of climate change so ocean acidification would continue unchecked. 

Second, if we keep adding greenhouse gases to the atmosphere, 

we’d have to continually increase the amount of geoengineering we 

were doing, so keep adding more and more aerosols to the stratosphere every year just to keep temperatures in balance, and that 

would lead to increased side effects and risks. 

And third, because of the long lifetime of carbon dioxide in the 

atmosphere, if we relied only on solar geoengineering, that would 

lead to a practically indefinite commitment to future generations to 
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either continue deploying it or accept the consequences of high 

CO2. 

However, as long as it’s considered as a supplement to cutting 

emissions, then it might reduce some climate damages and so it 

would be valuable to conduct the needed research. A coherent 

prioritized research effort needs to be driven by the end goal of 

supporting informed decisions regarding these approaches, and research would need to be integrated into the overall U.S. climate 

science research effort and should include explicit attention to research governance. 

The next step is probably to clearly articulate research needs and 

how to address them. This might benefit, for example, from an expert body like the National Academies. For stratospheric aerosol injection, we know that it works at least for a degree or two of cooling. It works in the sense of cooling the planet simply by analogy 

with what happens after large volcanic eruptions, and the observations made after eruptions have helped calibrate our climate models. Near-term research here is likely to continue to be primarily 

model-based, and once we better understand the uncertainties we 

need to address, it’s likely we would need some outdoor experiments to resolve key uncertainties, but I should emphasize that 

these would always be at a very small scale. Marine cloud brightening would also benefit from small-scale, controlled experiments, 

which would also help inform critical uncertainties in climate 

change science. All of this research will build on continued investments in climate modeling, in high-performance computing, and in 

our ability to collect observations about the Earth system. 

So in summary, I and I think many of my colleagues in the research community believe that even with our best efforts at mitigation, the risks of future climate change are sufficiently concerning 

that we may need to consider all of the options at our disposal. I 

conclude that it’s essential to conduct focused, goal-oriented research to support informed decisions but reiterate that this needs 

to be in addition to the work of reducing our emissions of greenhouse gases and not a substitute. 

Thank you, and I look forward to all of your questions. 

[The prepared statement of Dr. MacMartin follows:] 
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Chairman BIGGS. Thank you, Doctor. 

I now recognize Ms. Wanser for five minutes for her testimony. 

TESTIMONY OF MS. KELLY WANSER, 

PRINCIPAL DIRECTOR, 

MARINE CLOUD BRIGHTENING PROJECT, 

JOINT INSTITUTE FOR THE STUDY 

OF THE ATMOSPHERE AND OCEAN, 

UNIVERSITY OF WASHINGTON 

Ms. WANSER. Thank you. I should have some slides. 

Thank you, Members of the Committee. It’s an honor to be here, 

and I commend you for taking up this challenging topic. My name 

is Kelly Wanser. I spent 20 years as an executive and entrepreneur 

in the technology industry focused on understanding and securing 

large, complex systems. Ten years ago, I became interested in how 

we might apply technology to risks in the Earth system and helped 

form a collaboration that became the marine cloud brightening 

project. I’m now its Program Director. Prior to that, I served as an 

advisor to the laser inertial fusion energy program at Lawrence 

Livermore National Laboratory and as senior advisor to ocean conservancy, looking at ocean climate risk. 

I’m here today because increased heat in the atmosphere poses 

risks to our way of life and critical parts of nature we rely on. We 

may require options for directly reducing heat in the Earth system. 

There is a need and an opportunity for innovation, and there are 

important steps we can take in developing a research program. 

Small particles—aerosols—and the way they interact with clouds 

to reflect sunlight are one of the primary ways that nature keeps 

our planet cool. The most promising approaches to rapidly reducing 

heat in the climate involve adding particles to the atmosphere to 

slightly increase this reflective effect. 

One approach to reducing heat, marine cloud brightening—next 

slide—would use sea-salt mist sprayed from ships to brighten 

clouds over the ocean. Next slide. 

[Slide] 

Applied to a fraction of all marine clouds, it might offset 2 degrees of warming globally, and the way the particles brighten 

clouds and cool the system is a gap in our ability to forecast weather and climate, and in this way research in marine cloud brightening may be of strategic importance to emergency preparedness, 

national defense, and many industries. 

Today, we lack technical capabilities and scientific knowledge for 

marine cloud brightening or any proposed approach to rapidly reducing heat in the Earth system. Next slide. 

[Slide] 

Delivering aerosols with the right properties at sufficient scale is 

a hard engineering problem and takes time. Next slide. 

[Slide] 

Once we have technology, next steps are to build a system to enable small-scale field experiments to determine whether these ideas 

are feasible and basic processes to input to models. There is a welldefined research plan that starts with land-based testing, moves to 
73 

single ship studies, and finally to misting one region of clouds to 

determine brightening effects. This research plan will take years. 

Satellite—next slide. 

[Slide] 

Satellite, aerial and surface observations are critical and we will 

want to support our current infrastructure as well as leverage disruptive new technologies and remote sensing from innovative companies like Saildrone, Spire Aerospace, and others. The work will 

also require significant advances in modeling and data analysis 

and increased computing capacities to support assessment and prediction of effects. It will take a decade of core technology development and basic science to determine if any options are feasible and 

another decade to scale capabilities for readiness. Work must commence soon to produce knowledge and options within a time frame 

relevant to climate risks. With changes occurring around the world, 

it is likely and may be inevitable that others will develop capabilities. With a potential to produce geographically variable climate 

outcomes, the United States has a security interest in understanding and controlling them. 

Taken alone, capabilities for reducing heat in the atmosphere are 

not a solution. They should ultimately be considered as part of a 

portfolio within a management framework that includes emissions 

reduction, greenhouse gas removal, land and ocean management, 

industrial practices, economic incentives, and adaptation. Given the 

magnitude and urgency of the problem and our current lack of 

knowledge and capabilities, defining a research agenda and developing funding pathways for research may be critical. A National 

Academies study to help define a research agenda and establish a 

governance framework for research activities may be a valuable 

initial step. Next slide. 

[Slide] 

This type of work is not unprecedented. In 1934, the U.S. government undertook the largest effort to address an environment problem in our Nation’s history: planting 220 million trees through the 

center of the Midwest to address the great storm of the Dust Bowl. 

Now may be the time to research the possibility of shelter belts in 

the sky. 

[The prepared statement of Ms. Wanser follows:] 
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Chairman BIGGS. Thank you. I think each of the witnesses for 

your very interesting testimony. I recognize myself now for five 

minutes for questions. 

Dr. Rasch, I understand that most of the federal research on the 

topic of geoengineering has been conducted at our federal labs. Can 

you elaborate on how much funding is currently slated for this type 

of research? 

Dr. RASCH. To my knowledge, the current funding is restricted 

essentially to a few university professors through the National 

Science Foundation. The rest of it is being occasionally supported 

from various agencies to stay engaged in activities like the research 

reports which you’ve heard about but most of the other work that’s 

being done is being done through supportive philanthropic organizations or for free on weekends and evenings by scientists who are 

interested in these things. It probably is bounded by less than a 

million dollars a year. It could be a few hundred thousand dollars 

a year of supported research directly for geoengineering. That’s to 

my knowledge. I don’t really know. 

Chairman BIGGS. Any other panelists want to weigh in on that 

question? Dr. MacMartin? 

Dr. MACMARTIN. The National Center for Atmospheric Research 

has been providing computer time, which is supported by the NSF, 

but that’s basically—Phil’s answer is correct. 

Chairman BIGGS. And so I would guess that—and I don’t want 

to presume anything but it sounds like you would agree that the 

topic has not been adequately pursued in the recent phase? 

Dr. RASCH. Right. My reaction is that it’s very easy to identify 

the fact that a very small amount of effort has been put into this 

area and that progress could be made much more rapidly with a 

relatively small amount of funding. 

Chairman BIGGS. It leads me to ask why has geoengineering not 

received the same kind of funding as maybe some other types of 

research over the last 8 to ten years. Dr. Rasch? 

Dr. RASCH. Well, I think there’s a recognition by all that it’s 

quite a controversial subject of real concern to citizens of the 

United States and to other scientists as well, and there is some reluctance to take the first step is my sense. That’s my best answer. 

Chairman BIGGS. Dr. Majkut, or actually anyone on the panel, 

outside of the Federal Government, is—and you mentioned some of 

the philanthropic supporters of geoengineering research. What’s 

the postsecondary education or university level of research in this 

area? Ms. Wanser? 

Ms. WANSER. So the overall philanthropic funding in this area is, 

I would characterize it as maybe in the range of $1 to $2 million 

a year, mostly allocated towards one program, the stratospheric 

aerosol program at Harvard. For the most part my experience in 

the philanthropic community is that this subject matter is not yet 

acceptable for funding, so traditional sources of environmental and 

climate research funding in the philanthropic community are not 

yet funding in this area. 

Chairman BIGGS. And Dr. Majkut, how about universities? 

Dr. MAJKUT. Well, we know there’s a few research programs 

around the country, Harvard University, Washington, other individual scholars. Whether or not this particular item falls under a 
90 

research priority for a particular university I don’t think is a question that’s easy for me to answer. There are individual academics 

who put their energy into it, as Phil says, but it’s not a very large 

field as you go to these scientific meetings where geoengineering is 

discussed. You see that there’s a relatively small number of people 

working on these issues. 

Chairman BIGGS. Are other countries working on geoengineering 

research, Dr. MacMartin? 

Dr. MACMARTIN. So I think the largest program in the world is 

probably the one at Beijing Normal University in China but that’s 

relatively new and unclear exactly where they’re going with that, 

but in Europe there’s some small efforts as well but not substantially larger than what’s in the United States. 

Chairman BIGGS. So thinking of it in terms of global competition, 

it doesn’t sound like we’re falling behind global competitors, it’s 

just that we’re not advancing as rapidly as perhaps many or some 

would like. Is that fair to say? 

Dr. MACMARTIN. Not yet but that may change depending on China’s future—— 

Chairman BIGGS. Dr. Rasch? 

Dr. RASCH. It was just—I might beg to differ a little bit with Dr. 

MacMartin that my sense is that over the last five years or so, a 

variety of European countries have identified explicitly some funding for geoengineering research that amounts to a few million dollars a year perhaps for—at that level, which is substantially larger 

than the amounts that I could identify in the United States. 

Chairman BIGGS. Well, again, thank all of you for being here, 

and my time is expired, and I recognize the Ranking Member of 

the Environment Subcommittee, Ms. Bonamici. 

Ms. BONAMICI. Thank you, Mr. Chairman. 

Just to follow up on the Chairman’s questions about work being 

done internationally, were any of you at the conference in Berlin? 

Yes? So in terms—I know the Chairman mentioned global competition but we also need to I think have a conversation with the concerns, and Dr. Rasch, you recognize, as our constituents do, there’s 

some controversy and we need some ethical discussions and boundaries, and Dr. Majkut, you mentioned that there’s a statute in the 

United States that research needs to be reported and there needs 

to be some framework. So how much work is being done internationally on collaborating on some of these questions of what are 

the frameworks and what are the ethical considerations and how 

much is regulated in terms of—climate doesn’t know political 

boundaries so, you know, somebody in the United States has to 

comply with this law but what about internationally? Who’s leading that discussion? 

Dr. MAJKUT. So there are several newer organizations that are 

looking at the international aspects of this research and also, you 

know, geoengineering more broadly as something that might be 

used to prevent climate risk not represented here today. I think 

those discussions are beginning to occur but it’s—you know, they’re 

consigned to issues that are related to but not just scientific, right, 

so the moral and ethical frameworks in which we look at these 

questions. Those conversations are beginning. It’s still early stage. 
91 

Ms. BONAMICI. And how does the United States compare with 

other—you mentioned China, Russia, other countries that are 

maybe working on this in terms of having some sort of regulatory 

framework or guidance and ethical considerations. 

Dr. MAJKUT. I couldn’t say about the foreign countries, sorry, but 

the United States, I think, you know, as I testified, has a framework in place for any research that’s going to take place in the next 

few years, and because of the strength of our scientific community 

and the National Academy of Sciences, I expect that we will remain 

at the front of figuring how we can go about this research judiciously. 

Ms. BONAMICI. And Dr. MacMartin, we’ve heard today a few 

times that geoengineering is not going to be the magic bullet or a 

fix, it’s not a substitute for mitigation and adaptation, and you said 

that geoengineering could be part of the strategy. So could you 

please talk about the range of activities that would be included in 

mitigation and adaptation, and what mitigation work is still required to prevent the most catastrophic consequences of climate 

change and what role might geoengineering play in that in terms 

of priorities? 

Dr. MACMARTIN. So I think it is clearly that we eventually have 

to get to zero emissions or net zero emissions of carbon dioxide 

principally. Basically when we hit zero is when we stop making the 

problem worse, and the question really is how fast that happens 

because we can’t do that overnight. That would have serious economic consequences if we tried to do that instantly. And so the 

question in some sense is, how do you balance the needs of our— 

how do you balance the needs of our grandchildren to have a safe 

environment and to have a decent economy. So the best efforts at 

mitigation are still probably going to result in some serious climate 

damage. You can imagine using carbon dioxide removal in the long 

term to pull the CO2 levels back down and in the interim potentially thinking of solar geoengineering as a way to keep the temperatures from getting too bad so that you don’t do things like lose 

parts of Antarctic ice sheets while you’re waiting for the CO2 removal to bring us back down. 

Ms. BONAMICI. Does anybody else want to add to that, the question of—we know there’s a lot of interest in exploring 

geoengineering but what are the mitigation and adaptation activities that perhaps need to have priority? 

Dr. MAJKUT. Well, we know that, or our sense is that mitigation 

and adaptation are both beneficial today. The question of 

geoengineering is if it will be beneficial in the future. They’re very 

different by nature. Reducing emissions permanently reduces the 

net impact of humans on the climate. Potentially introducing these 

technologies at some later date will do that temporarily but their 

nature is very different. 

Ms. BONAMICI. Dr. Rasch? 

Dr. RASCH. If I can follow up, it’s just to affirm what Doug 

MacMartin said, which is essentially I think many of us view the 

sunlight reflection methods as being an interim solution which allows—provides some breathing space while the mitigation and adaptation measures take place, and I think we all believe that they 

should occur as rapidly as possible. Lots of us are hoping that the 
92 

carbon dioxide removal methodologies will be economically viable 

and provide a mechanism for drawing some of the CO2 out of the 

atmosphere, so that’s a very important strategy to consider. 

Ms. BONAMICI. Thank you. My time is expired. Thank you, Mr. 

Chairman. 

Chairman BIGGS. Thank you. 

The Chair recognizes Mr. Weber, the Chairman of the Energy 

Subcommittee, from Texas. 

Mr. WEBER. Thank you, Mr. Chairman. I appreciate it. 

Dr. Rasch, in your testimony you said you’d been kind of looking 

at this field for about ten years and you published 20 papers, or 

maybe it was in your comments before your testimony as I read 

through it, and you also cited another gentleman that had published 42 papers, and what was his name? 

Dr. RASCH. Ben Kravitz—— 

Mr. WEBER. Okay, and—— 

Dr. RASCH. —another colleague here at PNNL working with me. 

Mr. WEBER. And how long has he been in the field? 

Dr. RASCH. Probably ten years as well. He started as a Ph.D. student working for a very eminent professor who chose to support 

him to work in this area based on his work on volcanic eruptions 

because this is a related—the impacts of volcanoes are related to 

the ones we’re exploring today. 

Mr. WEBER. Right. So the theory and concept of geoengineering 

is not new in the scientific community. Would you say it’s just kind 

of taken off in the last 10 years? 

Dr. RASCH. Well, it’s interesting. You can go back to the 1960s 

and find conversations that have been occurring about 

geoengineering. It certainly started to receive a huge amount of attention following a paper that was published by a Nobel Prize-winning chemistry named Paul Crutzen in 2006, so it’s about ten years 

old. In fact, that scientist and that paper was what brought me into 

the field and it might have been some of the other people on this 

committee. 

Mr. WEBER. And is Paul Crutzen—what country is he from? 

Dr. RASCH. He has spent the last 30 years or so in Germany. He 

did have a position at my former institute, the National Center for 

Atmospheric Research, in Colorado, and he’s originally from Holland. 

Mr. WEBER. Okay, not that you know much about him. 

Dr. RASCH. I didn’t quite know how to answer that. 

Mr. WEBER. Well, we only have five minutes so—so he published 

the paper, and you got interested. Is he still active in this field? 

Dr. RASCH. He is engaging. He’s in his late 80s and ill so he’s 

not as heavily involved but he does actually endorse the importance of doing research in this area to this day. 

Mr. WEBER. Okay. So as we’ve heard today, research has been 

moving kind of slowly, and of course, you just described the last ten 

years, I guess. So how do you get that idea out there to make more 

people interested in it? In your opinion, what steps could be taken 

to increase the participation of researchers while encouraging experiments in geoengineering? What needs to be done? 
93 

Dr. RASCH. Well, I’m a strong advocate for this coherent research 

program that involves a set of five elements, which I’ve listed in 

my written testimony. 

Mr. WEBER. Okay. 

Dr. RASCH. And which I’d be happy to discuss. 

Mr. WEBER. Okay. So much of what we know today is based on 

computer climate modeling. So how would small-scale field experiments improve those models, and can you describe a small-scale experiment? 

Dr. RASCH. Sure. You saw some examples of some of the elements of a small-scale experiment on the slides Ms. Wanser 

showed, and—— 

Mr. WEBER. Did you all collaborate on those? 

Dr. RASCH. We have been working together. 

Mr. WEBER. Good. 

Dr. RASCH. I’m part of that marine cloud brightening team that’s 

located at the University of Washington, where I also have an appointment. 

So it would involve seeing whether we could—let’s talk about 

marine cloud brightening for a moment. It would—that one we 

know it is possible to make clouds more reflective but it only happens in certain circumstances, and we’re very—it’s very difficult to 

be precise about the circumstances that it can occur in. So what we 

would like to be able to do—first off, there are many variables that 

take place which could help to explain that. The weather situations 

and clouds could be part of it. We see these clouds form in the 

wake of freighters which have different technologies on board. They 

use different kinds of fuel. They use different emission—— 

Mr. WEBER. That’s kind of fascinating because those emissions 

that come from those freighters is producing a heat content, perhaps carrying CO2 obviously with it, and so you’re saying that in 

and of itself produces droplets that intermingle with the clouds? 

Dr. RASCH. It’s actually the particles that come out. If the emission controls on those ships were perfect, then they probably 

wouldn’t be producing these ship tracks. What happen is that every 

cloud drop wants to form on a particle, all cloud drops in the atmosphere, and these ships release some particles, and when they 

do, those particles act to allow more clouds—more drops to form in 

certain clouds. 

Mr. WEBER. So you can duplicate that process? 

Dr. RASCH. That’s part of it, so what we would like to see is if 

we can do it in precisely the circumstances because I was saying, 

as ships—one ship is different from another, and it’s very difficult 

to be precise about exactly what the conditions were that allows 

the brightening to occur, and we would like to be more precise 

about those things? 

Mr. WEBER. Okay. My time is expired, Mr. Chairman. Thank 

you. 

Chairman BIGGS. Thank you. 

The Chair recognizes the Ranking Member on the Energy Subcommittee, Mr. Veasey from Texas. 

Mr. VEASEY. Thank you, Mr. Chairman. 

In addition—and this is for all the witnesses to answer. In addition to the solar radiation management, one alternative climate 
94 

intervention strategy that the National Academies examined recently is carbon dioxide removal. What is the potential of carbon 

dioxide removal to play a significant role in our efforts to mitigate 

the effects of climate change? 

Dr. MACMARTIN. So there’s a number of ideas that have been 

suggested including bioenergy with carbon capture and sequestration, so basically you grow crops, you burn them in a power plant, 

you suck the CO2 out of the flue gas and store it underground, and 

the problem with ideas like that is that the scale that you need to 

do them on to make a dent in climate change is something of order 

the scale that we’re currently emitting CO2 at, which as a species 

is about 40 gigatons per year, and so unless you’re talking about 

pulling, you know, 5, 10, 15, 20 gigatons per year out of the atmosphere, it’s a pretty small dent. And the problem basically is that 

things like the bioenergy with carbon capture and storage would 

compete with land use that we use for food crops, and then there’s 

another set of ideas to directly capture it from the atmosphere, directly capture CO2 from the atmosphere. That is almost certain to 

be technically feasible but right now probably too expensive, and 

it’s almost certain to be cheaper to not put it in the first place than 

to take it out after you’ve put it in. And then there’s a variety of 

other ideas that are probably less well understood. So the bottom 

line is, all of the things need either—we need something that is 

scalable, cost-effective, and does not have substantial local impacts, 

and right now we don’t have any ideas that satisfy all three of 

those, which is why we would need more research in that, and if 

we don’t start now, it’s not going to happen. 

Ms. WANSER. I would add to that list genetically engineered organisms and plants that might more efficiently capture carbon in 

the way that nature does but in an accelerated fashion. Some of 

the new capabilities with genetic modification, the CRISPR technologies, may be relevant for investment in this area. 

I would also say that carbon removal capabilities at scale, many 

of them carry serious ecological consequences that also need to be 

evaluated as we look at them. 

Mr. VEASEY. Another controversial area in the Congress, the 

GMOs. 

Some of the riskier strategies for carbon dioxide removal include 

ocean iron fertilization and the large-scale enhanced weathering. 

What are the drawbacks to these strategies in an environmental 

and public-health context? 

Dr. MAJKUT. Well, those technologies, you know, could prospectively capture quite a bit of carbon dioxide from the atmosphere 

and retain it in places where it would be durable either the sea or 

in rocks. The issue, as Doug says, is to do this in a way that’s going 

to significantly affect how much excess CO2 is in the atmosphere. 

It’s going to take a lot of land or a lot of ocean, and the ecological 

effects of either of those things is not quite known. 

Mr. VEASEY. Also, I wanted to talk with you briefly about funding levels. You know, I’m very concerned, as a lot of people are, 

about federal R&D programs under this Administration. We saw in 

the budget proposal earlier this year, the Trump Administration 

supports very large cuts to research agencies. For example, the proposal included major cuts to climate modeling and Earth systems 
95 

sciences at the DOE. Will these funding cuts hurt or help us better 

understand the field of geoengineering? 

Ms. WANSER. So I think it’s important to acknowledge that if 

we’re interested in engineering the climate system that our capabilities or observing, analyzing and interpreting the information 

about the climate system are essential. So all of the platforms and 

capabilities and talent that we have are not only areas that we 

want to preserve but if we’re interested in active intervention in 

the Earth system, we would want to advance and enhance those capabilities. 

Dr. MACMARTIN. I would just second that. We need the same climate models. We need a lot of the same observational capacity, and 

we use the exact same high-performance computing. 

Mr. VEASEY. Thank you very much, Mr. Chairman. I yield back 

my time. 

Chairman BIGGS. Thank you. 

The Chair recognizes the gentleman from Florida, Mr. Posey. 

Mr. POSEY. Thank you, Mr. Chairman. Thank you for calling this 

very interesting hearing, and thank the witnesses for their informative testimony. 

Do you believe—this is for anyone on the panel, for all on the 

panel—there’s a risk that in starting to build geoengineering capabilities, we could lose control of them, and how do you think it 

would compare to the risk of bioengineering and nanotechnologies? 

Dr. RASCH. I’m willing to take a stab at it. I think scientists are 

all concerned about the possibility of this—us losing control of it 

and adopting it but I personally feel that it works better to operate 

from a position of knowledge about it rather than the absence of 

that knowledge, and I think the cat’s kind of out of the bag at this 

point in the game that the technology is possible. So I would prefer 

to be spun up on what it’s—— 

Mr. POSEY. Okay. Ms. Wanser, you had your hand up next. 

Ms. WANSER. Well, solar climate engineering technologies actually have a high barrier to entry, so they’re relatively expensive to 

engineer and relatively expensive to measure, and they scale linearly, so you evolve solar climate engineering technologies with a 

number of disbursals you have. They’re very easy to see and detect. 

Whereas nanotechnology and bioengineering techniques have very 

low barriers to entry. They now—you can now buy a kit to engineer 

organisms with CRISPR for less than $200, and you could release 

them into the wild. So the challenge with things like bio engineering is that they are low barriers to entry and self-replicating. So 

in some senses, solar climate engineering actually is less challenging from a governance perspective provided we have a framework in place. 

I disagree a little bit with Dr. Majkut that we already have one. 

I think it’s part of what we would want to define in conjunction 

with the research program. But I think some of the challenges here 

are a bit more straightforward than they are in some of these other 

fields. 

Mr. POSEY. Anyone else care to comment? 

Dr. MACMARTIN. Yeah, I just wanted to add, if we did put 

aerosols into the stratosphere at any point, the lifetime in the 

stratosphere is about a year or two, and so whatever we put up 
96 

there is just going to come back down. That also means that if you 

want to maintain it, you have to constantly be putting more in. So 

there’s less risk of it running away when you’re actually deploying 

it than there would be for, say, a biotechnology-type intervention. 

Mr. POSEY. Any hard evidence on the effect that subsurface activity has on the atmosphere? I mean, we know what ended the 

last Ice Age. It was an asteroid strike which basically created the 

Gulf of Mexico and darkened out the Earth for many, many years 

and allowed it to freeze over. There are some conditions that exist 

here now that have the potential to recreate that catastrophe. 

Some of the research I’ve seen at Yellowstone, the big volcano in 

the Azores that they say will cause 100-foot-high tsunami, you 

know, but your thoughts on how that may affect us? 

Dr. MAJKUT. Well, relevant to these questions, there’s a volcano, 

Mount Agung, which is on currently a level 3 eruption watch, so 

we may have a natural experiment coming up should it erupt and 

inject sulfates into the atmosphere. Then we would see a repeat of 

what previous volcanoes have done and probably some cooling influence, and thankfully the scientific community I believe is ready 

and standing by to observe that and understand the processes as 

best they can. That’s certainly true. 

Dr. RASCH. If I might follow up—— 

Mr. POSEY. Dr. Rasch? 

Dr. RASCH. —it’s to say just that the scientific community is very 

interested in a rapid response team for watching over these volcanic eruptions but they are sort of assembling it as we speak, and 

it’s not maybe quite as far along, as Joe mentioned. 

Mr. POSEY. One last question. What have other countries done 

so far in this realm? 

Dr. RASCH. The rapid response team is part—is an international 

effort. There’s certainly a very large and interested part of American U.S. scientists participating but that is an international activity. 

Mr. POSEY. Okay. Thank you, Mr. Chairman. My time’s expired. 

Chairman BIGGS. Thank you. 

I recognize the gentleman from California, Mr. McNerney. 

Mr. MCNERNEY. I thank the Chairman and I thank the witnesses. 

You have seen the legislation I am about to introduce. Do any 

of you have comments about that legislation, whether you think it’s 

useful or should be improved or anything like that? Anyone care 

to answer that question? 

Dr. RASCH. I’ve had only a chance to look at it very briefly and 

would be delighted to provide some more comments offline. 

Mr. MCNERNEY. Thank you. 

Dr. MAJKUT. I have the same idea. 

Mr. MCNERNEY. Thank you. 

Dr. MACMARTIN. So I haven’t read through it in complete detail 

but I think in general I’m very supportive of having the National 

Academies involved in trying to understand exactly—basically lay 

out the roadmap for research in this area as well as looking at the 

governance side of things. 

Mr. MCNERNEY. Thank you. 
97 

Ms. WANSER. As I mentioned in my remarks, I’m very supportive 

of the notion of a National Academies study process to help define 

a research agenda. The community to date in geoengineering has 

been very small and centered in modelers with some physicists and 

some ethicists and policy researchers. So I believe that that process 

could help expand the array of disciplines that we need to look at 

this area and also help to build consensus about what a research 

program should look like. 

Mr. MCNERNEY. Well, following up with that on a governance 

framework, what sort of scope of organizations and individuals 

should be involved in the development of a governance framework? 

Dr. MAJKUT. I think we should be looking at sort of all the concerned parties, right? So the scientific community plays a vital role. 

I think civil society should play some role as well, and I think Congress should take into consideration the idea that you might want 

to have a say in how these things get governed, and then going forward, we can also look at managing these types of things with 

international partners as well. 

Mr. MCNERNEY. Ms. Wanser, you mentioned that it would take 

about 20 years for the technology to be deployable. Would having 

a research governance mechanism speed up that timeline in your 

opinion? 

Ms. WANSER. At the moment, one of the barriers to technology 

development and field research is the lack of either a government 

framework or social license for the work. So I think it would reduce 

risk for people who would fund the research and people who would 

enter the field to have an appropriate governance framework to 

allow it to proceed. So yes. 

Mr. MCNERNEY. Very good. 

Do any of you know if there have been field tests on 

geoengineering that have been carried out by other countries? 

Dr. RASCH. I’m not aware of any. 

Dr. MACMARTIN. There’s been—there was a brief attempt in the 

U.K. to do an experiment that was just on a tethered hose so it was 

just developing hardware that didn’t actually take place, and there 

was an attempt in Russia a number of years ago to try to do something that was a bit of a stunt but it wasn’t really scientifically accurate. 

Mr. MCNERNEY. Do Russia and China have limitations on what 

their scientists are able to do in terms of geoengineering? 

Dr. MACMARTIN. So the program in China right now is purely 

based on climate modeling and much more focused on what the impacts of deploying solar geoengineering would be. I do know from 

conversations with them that they’re asking questions about 

whether their next phase of their research should involve some experimental work but they have not yet made any decisions about 

that. 

Mr. MCNERNEY. So we don’t need to be worried about them doing 

large-scale deployments? 

Dr. MACMARTIN. I don’t think we need to be worried about anybody doing large-scale deployments because if you want to do scientific research, the research questions are all about process uncertainties, you know, trying to understand chemical reaction rates in 
98 

the stratosphere and things like that, and they don’t require large 

tests to do those things. 

Mr. MCNERNEY. So then what are some of the key ethical questions that we should be considering in moving forward with this 

field of work? 

Dr. MACMARTIN. I think my personal answer to that would simply be that a lot of people are very concerned about the slippery 

slope and whether an effort in research is eventually going to lead 

to deployment, and I think a lot of people are very concerned about 

the research effort in geoengineering detracting from efforts in 

mitigation, and so in some sense the issues with ethics and governance are primarily wrapped up in involving the public participation 

and where we want to be going as a society in the future. 

Mr. MCNERNEY. Mr. Chairman, I want another five minutes. I 

yield back. 

Chairman BIGGS. Thank you, and the Chair recognizes the gentleman from Texas, Mr. Babin. 

Mr. BABIN. Thank you, Mr. Chairman. Extremely interesting topics, and I appreciate you convening this hearing and your witnesses 

being here. 

You’ve already alluded to it a little bit about the safety and environmental risks of this research being proposed, and we just talked 

about Russia and some of the other countries and maybe deploying 

fully things of this nature, and you mentioned a slippery slope, Dr. 

MacMartin, and what do you mean exactly by slippery slope? Is 

this something that you mess around with Mother Nature and it 

may turn into something that’s even worse than you’re trying to 

fix? 

Dr. MACMARTIN. I was actually referring to the societal process, 

the concern that if we start doing research, that eventually that’s 

going to lead to deployment, and people might think wait, wait, we 

haven’t actually decided on deployment yet. 

Mr. BABIN. Right. 

Dr. MACMARTIN. So that’s a concern that people have expressed. 

Mr. BABIN. Okay. But is that a concern with any of you folks 

that are involved in this, that we could unleash something irreversible if you continue to do this cloud brightening or the stratospheric 

procedure? Is that a possibility? 

Dr. RASCH. I think at the level that we’re talking about doing 

things right now, as I think Joe mentioned, the changes to the 

planet are vanishingly small. It would be hard for you to notice, to 

even detect it if you didn’t know it was happening. So it’s really 

tiny compared to, for example, the impact that flying an aircraft 

from Washington, D.C., to Seattle would have on the planet. So 

they’re small today. If one wants to get to the point of considering 

having a climate-altering effect, then the impacts get much more 

important to worry about, and we have to be more careful when 

things get ramped up to that time. 

Mr. BABIN. Right. 

Dr. RASCH. As Kelly mentioned, I think it would take 20 years 

to decide on whether we have a good enough understanding to decide that it might be useful to do this or not, if we’re going all out 

on it. 

Mr. BABIN. All right. Thank you. 
99 

Anybody else want to add to that? 

Dr. MAJKUT. Yeah, I think I would just reiterate that a lot of the 

sort of smaller-scale field experiments that scientists are presently 

proposing to do are going to be unnoticeable to the untrained eye. 

You need a really fancy experimental setup and cool instruments 

to even detect that it’s going on, right? Questions of, you know, 

does this research affect sort of other societal questions about how 

we address climate change are real but I think it’s—you know, it’s 

a bit of speculation to say whether that’ll cut one way or another. 

We should go about this judiciously and carefully and slowly and 

with an open and transparent process. I think that’s probably the 

best approach. 

Dr. MACMARTIN. I agree. 

Mr. BABIN. Okay. Yes, ma’am? 

Ms. WANSER. I think one of the things that may be helpful from 

a governance process or an oversight process is a definition of what 

we mean by research-scale or small-scale experiments and then lots 

of transparency with regard to that so that where it’s not easy for 

people to understand what the limits of these things are. We have 

some very bright, shiny lines between what we do for research and 

the kinds of things that would have greater impacts. 

Mr. BABIN. Okay. And while you’re at the mic, you discussed the 

need for research framework earlier in this field, and could you explain what your whole-systems approach to geoengineering research would be? 

Ms. WANSER. Well, probably not terribly briefly, but I think 

there’s—it’s what sometimes referred to as a transdisciplinary 

field, so we think about certainly the climate research part of it. 

We have a technology innovation component. We need to think how 

systems would interact together and how different actions taken on 

the Earth system would interact like policies that we make that 

change the forcings in the climate too. So part of a research program is to bring people who are not currently present into the discussion starting with aerosol engineers and other types of engineers who would be needed to think about how these things would 

actually work, looking at the innovations in observations measurement and computing. So today the experiment that I showed you 

about marine cloud brightening, they do observations like that now 

of pollutants, and when they go out and take those measurements, 

they bring them back. They take months to analyze the data. If 

we’re acting on the Earth system actively, we’re going to want information much faster and we’re going to need to improve our systems to do that. 

So when we think about the whole system, we have to think forward a little bit about what we’d be looking at in terms of the feedback to the perturbations that we make and how we need to understand them. Does that help? 

Mr. BABIN. Yes. Yes, it does. Thank you very much, and my time 

is expired, Mr. Chairman. Thank you. 

Chairman BIGGS. Thank you. The Chair recognizes the gentleman from New York, Mr. Tonko. 

Mr. TONKO. Thank you, Mr. Chair, and thank you to our impressive panel of witnesses for joining us today. 
100 

As the only New Yorker on the Committee, I would like to take 

a moment to give special thanks to Dr. Douglas MacMartin from 

Cornell University. We thank you for your time and your expertise, 

and we thank Cornell for the contributions it makes. 

The recently released 4th National Climate Assessment Climate 

Science Special Report represents the scientific collaboration of 

some 13 United States federal agencies with sign-off from the 

White House. That report found with high confidence a likely 

human contribution of well over 90 percent of the observed change 

between 1951 and 2010 in the global climate. Furthermore, the report found with very high confidence that the magnitude of climate 

change beyond the next few decades will depend primarily on the 

amount of greenhouse gases emitted globally and on the remaining 

uncertainty in the sensitivity of Earth’s climate to those emissions. 

We know the harms caused by climate change are grave and that 

they are growing. They have already done harm to human health, 

to water quality and availability, sea-level rise, and they have 

worsened natural disasters. For this and countless other reasons, 

failure to address climate change will result in significant economic 

harm to our country and her people. 

Given the conclusions of these impartial scientists and the widely 

accepted consensus that climate change is real and primarily driven by human activity, I urge all members of this Committee to 

move forward with this White House-approved consensus in mind. 

Geoengineering absolutely should be a part of the discussion of 

solutions, but with that said, we can’t lose sight of the fact that significant reductions in GHG emissions are indeed necessary. 

So for all of our witnesses, you have emphasized that numerous 

gaps remain in the scientific understanding of geoengineering technologies. Can each of you just briefly describe these gaps in the scientific understanding of geoengineering strategies? 

Dr. RASCH. Yeah, I’ll mention one or two because I could go on 

for the whole five minutes. So—— 

Mr. TONKO. One or two will do. 

Dr. RASCH. Okay. So we at the moment don’t—the situation of 

using geoengineering differs from either the marine cloud brightening or volcanoes because we would intend to put particles into 

the atmosphere continuously rather than they would just occur episodically, and we don’t know how the existing particles will respond to the—to putting in these kind of particles for long periods 

of time. Models tell us that it will be different from the way it 

would work for a volcano, let’s say, so that would be one example 

of something which we don’t know but we need more information. 

Mr. TONKO. Okay. Thank you. 

Doctor? 

Dr. MAJKUT. One particular aspect of this that really fascinates 

me is questions of when you have these sort of compensating mechanisms of warming at the surface and cooling in other parts—either concentrated parts of the atmosphere or high up in the atmosphere, what are going to be the effects on other conditions that we 

care about, not just temperature, right? So biology, the oceans. I 

think a lot of these downstream issues need to be investigated 

much further. 

Mr. TONKO. Thank you. 
101 

And Dr. MacMartin? 

Dr. MACMARTIN. So I would second both of those and just reiterate that we know a fair amount of stratospheric aerosols just 

from observing volcanic eruptions, but it is different from a large 

volcanic eruption. We don’t actually have any observations of 

geoengineering obviously and so we sort of have to figure out as we 

go how do we go collect that knowledge about what the processes 

in the stratosphere are going to be. 

Mr. TONKO. Okay. Thank you. 

Ms. WANSER. Well, we don’t yet have any technology for producing aerosols of the type and at the scale that we’re talking 

about for this, and until we know what the limits of those technologies are, what we’re inputting to our models is very much 

guesswork, and we also don’t know how to measure and detect in 

real time. 

Mr. TONKO. So then what would the next steps be to address 

these gaps? Any recommendations to the Committee? 

Dr. MACMARTIN. So I think one step is clearly to actually just 

start by saying if we want to support informed decisions in 10, 15, 

20 years to be very careful that writing down what all the uncertainties are and propagating those through the climate models, so 

if there’s something uncertain about stratospheric aerosol microphysics or chemistry, how important is that in terms of influencing 

our decisions and therefore what experiments would we need to do 

to help resolve those uncertainties. That’s the type of research that 

I think we need to be focused on. 

Mr. TONKO. Anyone else? 

Dr. RASCH. Yeah. I mean, I will just say that there are—I think 

one of the things that is missing so far is that the research that’s 

been done today is primarily curiosity driven and people have 

picked at various elements of the geoengineering unknowns, but I 

think we need to do it in a much more systematic way to try and 

move pretty quickly towards getting an idea about what are the 

tradeoffs involved in this work. 

Mr. TONKO. Okay. With that, I yield back, Mr. Chair. 

Chairman BIGGS. Thank you. 

The Chair recognizes the gentleman from Illinois, Mr. Foster. 

Mr. FOSTER. Thank you, Mr. Chair, and thank you for holding 

this hearing. It really shows a level of engagement on this issue 

that I think is overdue and very welcome. 

Are there any sort of zero-order either cost estimates or estimates for the amount of aerosols that you’d need, for example, to 

reverse a 2-degree warming or a calculation of, you know, if you 

have a gigaton of coal, how many gigatons or tons of aerosols you 

have to put into the atmosphere? Are there any rough estimates 

based on volcanoes and similar that people have done? 

Dr. MACMARTIN. So I’ll give you a rough estimate that 1 degree 

of—1 degree Celsius of cooling, so 1.8 Fahrenheit is, say, 10 megatons of sulfur dioxide into the upper atmosphere, and in terms of 

cost, there’s estimates of costs that are in the billions of dollars, but 

quite frankly, I don’t think that the direct economic costs of bringing material to the stratosphere, those probably are not the reasons 

why we would—how we would evaluate this. It’s far more a question of what the risks and the side effects are. 
102 

Mr. FOSTER. Right. Okay. So it wouldn’t be the direct costs of actually even carrying this out. They all would be dwarfed by, you 

know, the trillion-dollar scale effects of, you know—— 

Dr. MACMARTIN. Yeah, and the direct costs of doing it is probably more observational capacity of satellites and things to monitor 

things. 

Mr. FOSTER. Which brings me to the issue of international governance because, you know, Congress can pass all the laws we 

want and if, you know, China decides that it wants to preserve its 

islands it just built in the South China Sea or, you know, Bangladesh or Micronesia decides that they’re going to be underwater 

in short order, you know, their interests are not necessarily aligned 

with ours, or if you do this and you see it’s going to redistribute 

rainfall globally, you know, or reverse the Gulf stream or stop the 

Gulf stream. You know, there are worries like that that are out 

there. And so it seems like you need an international mechanism 

for someone who will say no, you cannot do that. And you know, 

we’re in a tough situation right now because we have an Administration that’s done things like reject the Paris agreement. And so 

I was wondering if there are serious, maybe outside this country, 

serious discussions of how we’re going to regulate this internationally. 

Dr. MACMARTIN. Discussions are beginning but, you know, as we 

kind of see here today, this is a new topic for conversation, particularly for a lot of policymakers. So they’re sort of at their early 

stages. I highlight in my testimony some ideas. I’d be happy to follow up with you about them in more detail about how we can accomplish some of these questions here and sort of build a national 

governance model that could influence how things work internationally. I think that would be a good thing to talk about. But 

yeah, we’re still at very early stages in terms of international 

issues. 

Mr. FOSTER. It also seems to me that the level of controversy 

having to do with CO2 removal strategies is much lower than albedo modification, particularly atmospheric. Is that a fair reading 

of sort of your—the attitudes you see toward this, that the objections of CO2 removal are simply going to cost a lot more than 

averting the emissions in the first place. 

Dr. MACMARTIN. So in terms of direct climate impacts, then 

there’s basically no climate impacts from pulling CO2 out. It just— 

that solves the root of the problem. But I think one of the reasons 

there hasn’t been any pushback is perhaps people don’t quite get 

what the local impacts might be. So if you need to displace land 

area the size of India for food crops for bioenergy, I think that 

would actually have some serious consequences. So I think yes, 

people are less concerned about CDR but maybe they should be a 

little bit more concerned than they are. 

Mr. FOSTER. That would be a very technology-specific thing. 

Dr. MACMARTIN. Very, very specific to the technology. 

Mr. FOSTER. And so now, when you got these sort of natural experiments from volcanoes going off, how frequent are volcanoes 

that actually provide you relevant data and get enough aerosols up 

in the stratosphere that you actually get a useful volcano? Do they 

happen once a decade, once a century, or once every few years? 
103 

Dr. RASCH. Probably less frequently than once a decade and more 

frequently than once a century they come alive. 

Mr. FOSTER. All right. 

Dr. RASCH. They do have smaller-scale volcanoes. One went off 

in Iceland a few years ago that was useful for understanding some 

aspects of, for example, the way clouds could be brightened by addition of extra particles in the atmosphere. But the really big eruptions like Pinatubo or Agung, those are—— 

Mr. FOSTER. Those are rare. I remember after that volcano happened, I called up Nathan Myhrvold, who you’re probably well 

aware is one of the, you know, people of means interested in paying 

for this, and he indicated that it simply didn’t put enough into the 

high stratosphere to be useful. 

Dr. RASCH. For the stratospheric aerosol analog. 

Mr. FOSTER. Right. But now, if you look at the historic record 

of—— 

Chairman BIGGS. The gentleman’s time is expired. 

Mr. FOSTER. Excuse me. I yield back. 

Chairman BIGGS. Thank you, Mr. Foster. I appreciate that. 

The Chair recognizes the gentleman from Indiana, Mr. Banks. 

Mr. BANKS. Thank you, Mr. Chairman. It’s a very interesting discussion today. Thank you for being here. 

I believe like probably most of my colleagues do that it’s impera- tive that we deal with the reality of a $20 trillion national debt. 

Even though that debt is driven by mandatory spending programs, 

our constituents at home expect us to find savings wherever possible. We’ve seen in my home State of Indiana the innovative utilization of public-private partnerships to overcome this dilemma. 

One example I’d like to point to is the Indiana Biosciences Research Institute. The Institute is a public-private partnership between universities and research institutions, industry and the 

State of Indiana. The Institute fosters collaboration between these 

entities in life sciences research and support the commercialization 

of their research. One big advantage, in my view, of an arrangement like this is that the participation of industry ensures that research will be directed toward endeavors that are commercially viable and produce a positive return on investment. 

So with that, I’d like to hear the panel’s perspective on the potential for public-private partnerships to advance research in this 

area. Dr. Rasch, if you could respond to that first, we’d appreciate 

it. 

Dr. RASCH. Well, I know that my laboratory is quite interested 

in these public-private partnerships. I have to admit I’m not an expert in the area and can’t tell you about the potential for this particular application. 

Mr. BANKS. Okay. And next to you? 

Dr. MAJKUT. I would also have to demur. I think public-private 

partnerships are useful in many contexts but it’s hard for me to 

state strongly one way or another on this issue. 

Mr. BANKS. Ms. Wanser, I see you raising your hand. 

Ms. WANSER. So I see tremendous opportunity for public-private 

partnerships and the disruptive innovation that’s happening in remote sensing and in computing. So for the types of capabilities that 

we need to monitor and interpret what we would do in 
104 

geoengineering, there are particular opportunities to work with 

those companies to do things in a way that’s potentially an order 

or two orders of magnitude less expensive than we do it now in satellite observations, in ocean observations, the opportunity to have 

much more comprehensive Earth coverage and a much more granular level, and at the same time I think that are big opportunities 

for partnerships in the computing space for the adoption of cloud 

computing for some of the workloads that we do in this area that 

could be done on the public cloud in a cheaper and more agile way 

and opportunities to explore exoscale computing for the kinds of 

things we haven’t solved yet in terms of understanding the Earth 

system more rapidly. 

Mr. BANKS. So you agree that public-private partnerships are 

fruitful, but do you believe that the environment exists to further 

public-private partnerships as it stands today? 

Ms. WANSER. My experience leads me to believe—to be hopeful, 

yes. 

Mr. BANKS. Thank you. I yield back. 

Chairman BIGGS. Thank you. I thank each of the witnesses for 

being here today and a very interesting Committee hearing, and 

appreciate the members and their questions. 

The record will remain open for two weeks for additional written 

comments and written questions from members. 

And this hearing is adjourned. 

[Whereupon, at 11:44 a.m., the Subcommittees were adjourned.] 
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Appendix I 

ADDITIONAL MATERIAL FOR THE RECORD
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STATEMENT SUBMITTED BY FULL COMMITTEE

RANKING MEMBER EDDIE BERNICE JOHNSON
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LETTER SUBMITTED BY SUBCOMMITTEE ON ENVIRONMENT

RANKING MEMBER SUZANNE BONAMICI
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STATEMENT SUBMITTED BY RANKING MEMBER

EDDIE BERNICE JOHNSON
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