# Presentation: 454433

## The Global Effort to Understand Carbon Dioxide

- James R. Mahoney, Ph.D.
- Assistant Secretary of Commerce for Oceans and AtmosphereNOAA Deputy Administrator
- Director: US Climate Change Science Program
- September 26, 2005

**Notes:**
I would like to begin by dedicating my presentation to the memory of accomplishments of Dr. Dave Keeling.

It is an honor to open the Seventh International Carbon Dioxide Conference here in Boulder, Colorado, which is the first of these conferences to be held in the United States. 

Chronology of CO2 Conferences
1981 – Bern, Switzerland – Bern CO2 Symposium
1985 – Kandersteg, Switzerland – International Conference of Atmospheric CO2
1989 – Hinterzarten, Germany – International Conference on Analysis and Evaluation of Atmospheric CO2 Data Past and Present
1993 – Carqueiranne, France – Fourth International CO2 Conference
1997 – Cains, Australia – Fifth International CO2 Conference
2001 – Sendal, Japan – Sixth International CO2 Conference
2005 – Boulder, CO – Seventh International CO2 Conference

## Outline

- Carbon Dioxide Variability
- Role of Atmosphere in Carbon Cycle
- Role of Oceans in Carbon Cycle
- Role of Terrestrial Processes in Carbon Cycle
- Future Directions in Assessing the Carbon Cycle

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
Long Term CO2 Record (1 slide)
 Atmosphere (Keeling Graph, Forcings of Atmos Constituents, GAW, CO2 Concentration, Interpretive Analysis – 5 slides)
Oceans (Ocean Carbon Inventory, Sea-air gas exchange of CO2 – 2 slides)
Terrestrial – (CO2 partitioning, CO2 in Air – 2 slides)
Future Directions – (GEO, CCSP, Closing Slide – 3 slides)

TRANSITION TO LONG TERM CO2 RECORD SLIDE...

## Long Term Record of Atmospheric CO2

- Increase in CO2 in the past 100 years is unprecedented in ~450ky
- Modern record shows increasing NH source throughout century
- Interhemispheric difference has been increasing
- Seasonal Cycle is largest in NH

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
This plot is from the Climate Change Science Program Strategic Plan (Chapter 2), showing the 

Vostok record (blue), 
recent South Pole firn (snow) air measurements (pink), 
the modern South Pole record since 1957 (red), 
the modern Mauna Loa record (Green). -- JHB

This slide is an excellent example how efforts studying snow, ice, and other geological reservoirs can help us give us perspective and understand where today’s process fit in the global picture. 

(The paleo community will be represented fairly strongly at this meeting – JHB)

TRANSITION TO ATMOSPHERIC PROCESSES...

## Atmospheric CO2

**Notes:**
The atmosphere serves as a quantitative measure of, and diagnostic for, the input from fossil fuel combustion and more generally, for imbalances in the terrestrial and oceanic carbon cycles.  Atmospheric CO2 is also one of the important factors determining the earth’s climate. ( PT)

## Atmospheric CO2 at Mauna Loa Observatory

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
This global increase in atmospheric CO2, its implications and our efforts in identifying, understanding, and mitigating them are the reason for this meeting and all of the research it represents.  

STARTED BY DAVE KEELING in 1958, Mauna Loa Record for atmospheric CO2, updated to 2005.  
This record, along with that at the South Pole is the longest running record of direct atmospheric measurements of CO2 and it shows the continuing increase in atmospheric burden. 
The seasonal cycle, of course, is evident and due to exchange of CO2 with terrestrial plants and soils -- JHB

This record closely reflects the global average.  
The long-term global increase in CO2 is not as great as it would be owing to fossil fuel sources alone.  
This strongly suggests a sink for CO2, which subsequent investigations have indicated is located mainly in the northern hemisphere.  
Some of this sink can be accounted for by oceanic uptake, but a large component is associated with terrestrial systems.  -- JHB

Current Atmospheric Concentration of CO2: 380 ppm.   Without ocean uptake, concentrations would be approximately 435 ppm (Tim – is that just oceanic uptake or does the calculation include the terrestrial contribution? – JHB)    Ocean-uptake fraction has decreased from 28%-34% to 26%  (Sabine et al. 2004)  -- TE

## Radiative Forcing by Long-Lived Atmospheric Gases

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
90% of the increase in climate forcing in recent years can be attributed to increases in CO2 and is likely to continue that way. 

Some gases (e.g., CFCs) are actually decreasing, owing to international agreement (Montreal Protocol). 

CO2 has lower per molecule radiative forcing, but it is significantly more abundant.
10 Minor, CFCs, N20 – ppt
CH4 – ppb
CO2 - ppm

## Global Atmospheric Watch (WMO/GAW) Monitoring Sites for CO2

- Monitoring Stations for Carbon Dioxide (CO2)

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
This map shows the current CO2 monitoring locations for the WMO Global Atmospheric Watch Programme (GAW).  NOAA is an active member of GAW and many of the scientists attending the meeting are as well – providing data, guidance and advice, and maintaining data bases.  The sites shown here represent either weekly or continuous measurements of CO2 in the atmosphere.  It is anticipated that the GCOS Steering Committee in October will formally adopt the GAW network as a major component of GCOS.  

GCOS and the GAW network are a significant contribution to the climate observations for the Global Earth Observation System of Systems, or GEOSS.  GEOSS is aimed to be an integrated, coordinated, sustained observing system to “take the pulse of the Earth”.  The concept began with a Summit in Washington, DC in 2003 and has double in country participation since then.  NOAA has the lead on the U.S. contribution to GEOSS, of which climate observations play an important role and climate information is one of the nine societal benefits.  

Footnote:  About 2/3 of the GAW sites are from the NOAA/CMDL Carbon Cycle network, but they are operated by our international partners, who perform tasks from collecting air to be sent to Boulder, to maintaining associated instrumentation, to reporting ancillary data.  The NOAA network would not function without the international cooperation.  

*Jim M. needs to be aware of this, but also, since this is an international meeting, we want to be careful not to rub people’s noses in the fact that NOAA carries the lion’s share of the global atmospheric monitoring system.

## http://gaw.kishou.go.jp/wdcgg.html

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
This map, a product of the WMO/GAW World Data Centre for Greenhouse Gases (WDCGG) is derived from atmospheric CO2 measurements since 1980.  (Tip the hat to the WDC)

The interhemispheric gradient is evident in the map, as are seasonal cycles and the long-term increase in concentration.  Regional sources and sinks are also hinted at in this plot.

Concentrations around the mid 1980s are no where near the current concentrations.

We have embarked on understanding regional climate effects and any data set (such as this one) towards improving the understand of regional and global scale climate patterns in the atmosphere are a great contribution to the research.

## Data-Driven Interpretive Analysis:Identifying Global Sources and Sinks

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
This is a good example of a data-driven interpretive analysis.  In this case, we can compare C)2 to other conservative species to determine sources and sinks.  (LEADS YOU INTO THE TRANSITION TO OCEAN PROCESSES)

THE ATMOSPHERE AS A DIAGNOSTIC FOR THE CARBON CYCLE.  Left: observed annual average CO2 concentration (1998-2004) as a function of latitude, relative to the concentration at the South Pole.  The red line is the same for SF6, multiplied by the ratio of global fossil fuel carbon emissions to global SF6 emissions.  SF6 is a good proxy for fossil fuel CO2 emissions because they are emitted year-round at the same latitudes as fossil fuel burning.  With this adjustment, the observed SF6 curve portrays what the atmospheric north-south gradient of CO2 would look like in the absence of any other sources/sinks of CO2.  -- Pieter Tans, JHB

Right:  Subtracting the fossil fuel CO2 gradient from the observed CO2 gradient unveils what the gradient would look like due to all non-fossil fuel sources/sinks.  It shows a sink in the Southern Ocean, a major source in the tropics, and a large sink in the Northern Hemisphere peaking at about 40 deg. North. – Pieter Tans, JHB

(**)Note:  the multiplication factor is moles of CO2 emitted per year from global fossil fuel burning divided by the number of moles per year of global SF6 emissions.  The latter has been determined from the average atmospheric growth rate of SF6 during 1998-2004.  SF6 atmospheric lifetime ~3000 y.  SF6 emissions (entirely human) are associated with electricity use – transformer isulation. – Pieter Tans, JHB

TRANSITION TO OCEAN PROCESSES....

## Oceanic Processes

## Column inventory of anthropogenic CO2 in the ocean (mol m2). 
High inventories are associated with deep water formation in the North Atlantic and intermediate and mode water formation between 30° and 50°S. 
Total inventory of shaded regions is 106 ± 17 Pg C.  (From Sabine et al. 2004)

- High inventories are associated with deep water formation in the North Atlantic and intermediate and mode water formation between 30° and 50°S.
- Total inventory of shaded regions is 106 ± 17 Pg C.  (From Sabine et al. 2004)

- Ocean Carbon Inventory

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
Mention inventory differences...  For example, NADW results in a greater inventory in North Atlantic
Ocean Carbon Inventory
This inventory came from the Global Ocean CO2 survey (WOCE and JGOFS), conducted during the 1990s, through a large-scale international effort. 
This global data set revealed that, since the beginning of the industrial revolution, the oceans have taken up approximately half of the CO2 released from burning fossil fuels. 
This measurable increase of anthropogenic CO2 in the oceans has caused a pH drop of more than 0.1 pH units.
Impacts of Increased Oceanic Carbon
 Recent field and laboratory studies reveal that the carbonate chemistry of seawater has a profound effect on the calcification rates of individual species and communities of planktonic and benthic organisms.
  This acidification leads to alteration of ocean ecosystems..  e.g. impacts to planktonic and benthic habitats...
  Ocean acidification is linked to CO2 uptake from the atmosphere (the greater the acidification, the less efficient the uptake from the atmosphere)
To properly assess the future role of the ocean in the carbon cycle, research needs to be focused on:
1)  Ocean/Atmosphere feedbacks due to changes in oceanic physics (e.g. circulation)
2) Ocean/Atmosphere feedbacks due to changes in oceanic biology (e.g. calcification of organisms which are capable of altering oceanic pH) 

## Sea-air exchange of carbon dioxide

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
ESTIMATES OF NET ANNUAL SEA-TO-AIR GAS EXCHANGE OF CO2.  
Based on a compilation by Taro Takahashi (Lamont Doherty Earth Observatory) of measurements of the partial pressure of CO2 in surface waters, and a relationship between average wind speed and the velocity of gas exchange.  
BLUE: net uptake by the oceans    
RED: net outgassing by the oceans    
The patterns reflects the ocean circulation and biology.
The Atlantic Ocean as a whole, which has 23.5% of the global ocean area, is the strongest sink (41%).
Mid-latitude sinks are almost compensated by Equatorial Sources
Over the long term (millennial time scales) the ocean has the potential to absorb as much as 90% of the anthropogenic CO2 that is released to the atmosphere, with a substantial change in pH (0.4 units on average).
TRANSITION TO TERRESTRIAL PROCESSES...

## Terrestrial Processes

## Terrestrial biosphere takes up approximately three billion tons of human emitted carbon dioxide per year

- Carbon Dioxide Partitioning

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
There is significant year-to-year variability in net fluxes.  What happened in 1998 is still an active area of research and debate.  Widespread fires in 1998 is a leading hypothesis.

## Average concentrations of CO2 in marine surface air indicate that the continent of North America could be a net sink of CO2.  
Or is this a more “local” effect that is caused mainly by sources/sinks in the ocean basins?

- Or is this a more “local” effect that is caused mainly by sources/sinks in the ocean basins?

- parts per million

- CO2 in Air:North Atlantic minus North Pacific

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
Slide provided by Pieter Tans.  

Based on 7 CMDL sites in the N Atlantic basin and 11 sites in the N Pacific basin.

Uncertainty of the difference in gray color.  

## Future Directions

## US Effort—Climate Change Science Program (CCSP)

- Guides and directs federal research efforts
- Answers emerging climate science questions addresses key climate research challenges
- Involves 13 Federal Agencies/Departments
- Overseen by Ministerial/Cabinet-level officials
- Operates on a ~$2B annual expenditure

- Seventh International Carbon Dioxide Conference, Boulder CO

## CCSP Strategic Plan(www.climatescience.gov)

- Chapter 3:	Atmospheric Composition
- Chapter 7:	Carbon Cycle
- Chapter 12:	Observing and Monitoring the 	Climate System
- S&A Product 2.2:  Will provide a synthesis and integration of the current knowledge of the North American carbon budget and its context within the global carbon cycle. In a format useful to decisionmakers

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
The CCSP Strategic Plan is a comprehensive approach to enhancing the scientific understanding of climate change.  Three Chapters in the Plan directly address CO2 and the carbon cycle.

CCSP 2.2:  Will provide a synthesis and integration of the current knowledge of the North American carbon budget and its context within the global carbon cycle. In a format useful to decisionmakers, it will:

1)  Summarize our knowledge of carbon cycle properties and changes relevant to the contributions of and impacts upon the United States and the rest of the world.

2)  Provide scientific information for U.S. decision support focused on key issues for carbon management and policy. 

## International Efforts— GEOSS

- Leadership in development and implementation of the Global Earth Observation System of Systems (GEOSS)
- GCOS is a major contribution to GEOSS for climate observations
- GEOSS supports integrated global observations of CO2 & related gases
- Climate Technical Reference Document (USG document)

- Seventh International Carbon Dioxide Conference, Boulder CO

## Charles David Keeling1928—2005

- Charles David Keeling1928—2005

- Seventh International Carbon Dioxide Conference, Boulder CO

**Notes:**
In closing, I would like to return to my dedication to Dr. Dave Keeling and make the point that we are all here trying to expand on his great accomplishments and advancement in CO2 measurements and the understand of CO2.