Archive of ICDC7
This is a condensed archived version of the talks presented at ICDC7, September 2005
Overview
Conference Announcement and Overview
September 25th-30th, 2005
Summary:
Since 1981, the international community of carbon dioxide research scientists has held a Carbon Dioxide Conference every four years. The word carbon has become synonymous with climate, generating substantial interest across broad fields of science, technology and policy. At the 6th conference held in Sendai, Japan in 2001 (about 300 attendees compared to about 40 at Bern, Switzerland in 1981) it was decided that the 7th conference in 2005 would be held in the U.S. (for the first time) and be organized by NOAA/CMDL.
Areas of interest include atmospheric monitoring networks, ocean measurements, terrestrial ecosystems and fluxnets, carbon cycle process models in all of these settings, inverse transport models that infer surface source/sink patterns from the observations, new observational techniques, and the ice core record. New areas will be carbon sequestration (both natural and engineered) and human dimensions such as fossil fuel use and land-use decisions. In the past, a special issue of a peer-reviewed scientific journal has been dedicated to a sub-set of papers based on oral presentations and posters presented at the conferences. Guest Editors will be chosen to continue this tradition.
The main sponsors of the conference will be the World Meteorological Organization (WMO), DOC/NOAA/OAR, and the U.S. Carbon Cycle Interagency Working Group, which is comprised of members of U.S. Federal agencies including DOE, NASA, NOAA, NSF, USDA, and USGS.
Background:
The implications of the observed increase in concentration of atmospheric carbon dioxide for global climate change, and the inherently international scope of the associated scientific and public policy issues, have led to a series of international scientific meetings to gain a better understanding of the global carbon cycle. Beginning in 1981, the international community of carbon dioxide research scientists has held a Carbon Dioxide Conference every four years. The first meeting in Bern, Switzerland, called the "Bern Carbon Dioxide Symposium", focused primarily on atmospheric measurements of carbon dioxide and related species. In subsequent meetings (Kandersteg, Switzerland 1985, Hinterzarten, Germany 1989, Carqueiranne, France 1993, Cairns, Australia 1997, and Sendai, Japan 2001) attention has been focused on obtaining a better understanding of the global carbon cycle.
ICDC7 will be the first of this series of conferences to be convened in the United States. An estimated 500 participants are expected. The attendance at the sixth conference, held in Sendai, Japan in October of 2001 was approximately 300 participants. Many scientists did not attend the Sendai conference due to travel restrictions and concerns following the September 11, 2001 attacks on the World Trade Center and the Pentagon.
Conference Objective:
The purpose of this conference is to bring together scientists from varied disciplines to assess the current state of knowledge, identify gaps in understanding, and communicate the most recent results pertinent to the global carbon cycle, with an emphasis on understanding the contemporary increase of atmospheric carbon dioxide. Topics will include atmospheric and oceanic measurements and monitoring networks (including all species that provide insight into the carbon cycle), terrestrial ecosystems and land use change, carbon cycle process models, source/sink inverse models, the ice core record of carbon dioxide and methane, new observational techniques, long-term potentials and vulnerabilities of carbon sequestration, and the human impact on the carbon cycle.
Conference Themes
The conference sessions will be organized around five major themes as presented here:
Theme 1. THE FATE OF FOSSIL FUEL EMISSIONS
The amount of CO2 in the atmosphere has increased substantially since pre-industrial times, owing primarily to fossil fuel carbon emissions. A fraction of this has been further redistributed to the oceans and terrestrial biosphere by natural processes. What do the observed spatial patterns and time series’ in the atmosphere and oceans reveal about the flows of natural and anthropogenic carbon? This theme includes observations of CO2, CH4, their isotopic ratios, and any additional observations that provide explanatory power. It also includes patterns and mechanisms of air-sea gas exchange, inverse models that turn concentration patterns into large-scale flux estimates, and new developments in instrumentation to enhance our observational power necessary for increasing our understanding of carbon cycle processes.
Theme 2. LAND USE AND THE TERRESTRIAL CARBON CYCLE
Land management over past centuries has been the second largest contributor to global carbon emissions. Furthermore, most of the observed inter-annual variation of the rate of increase in the atmosphere is caused by varying exchange with the terrestrial biosphere. How can we quantify and understand the effects of land management on the carbon cycle? How can insight be gained into natural variations? Flux measurements, studies of the effects of wildfires, logging, soil management, urbanization, dams and reservoirs, woody encroachment, and seasonal to sub-decadal climate variations are examples of topics that fit this theme.
Theme 3. CARBON CYCLE RESPONSE TO ENVIRONMENTAL CHANGE
The carbon cycle, and thus the course of atmospheric CO2 and CH4, could be strongly influenced by Arctic warming, surface ocean stratification, moisture in terrestrial ecosystems, sea level rise, and the stability of methane clathrates, among others. How can we improve understanding and provide early warning of significant changes? Ice core and sediment data have revealed major shifts in the recent geological past, and analysis of these data is one approach to gain insight. Did climate change drive the observed changes in CO2 and CH4, or vice versa? What indicators in these data might have application today?
Theme 4. EFFECTS OF HIGH CO2 ON LAND AND OCEAN ECOSYSTEMS
Some evidence suggests that increasing levels of CO2 may increase rates of photosynthesis, change nutrient utilization, and alter demand for trace metals, causing further changes throughout ecosystems. Increasing CO2 in the oceans lowers pH, and there is evidence of detrimental effects on coral reef communities and organisms forming carbonate shells. What are the effects high CO2 has on the earth system other than simply the radiative forcing of climate?
Theme 5. MANAGING THE CARBON CYCLE
Anthropogenic emissions, emissions limitations, sequestration, and ocean chemistry will likely play leading roles in the future atmospheric CO2 burden. Coupled models will be required for long term projections. How can we gain enough confidence in these models for them to aid in decision making? Which features can be validated? Can we estimate the length of time that a particular sequestration option is secure? What are biophysical limits of biological sequestration? How much can be stored in geological reservoirs, how much in the oceans? What are likely environmental impacts of different strategies? How does the effectiveness of sequestration compare to decreasing the "carbon intensity" of our activities? Finally, methods, including instrumentation, need to be developed for independent verification of emissions and sequestration.
Conference History
A brief history of the International Carbon Dioxide Conferences
The CO2 conferences form a series bringing together scientists to communicate the most recent results pertinent to the global carbon cycle, with special emphasis on the current increase of atmospheric CO2. These international meetings take place once every four years. The World Meteorological Organization has been a sponsor of most of the events. The next meeting has been scheduled for 25-30 September, 2005, near Boulder, Colorado.
The first meeting took place in 1981 in Bern, Switzerland, and was called the "Bern CO2 Symposium". The University of Bern and the WMO sponsored the event. About 40 scientists attended. The meeting's focus was strongly on atmospheric measurements of CO2 and related species, with some attention to model estimates of oceanic and terrestrial CO2 uptake. A series of papers from the meeting was published in a special issue of Journal of Geophysical Research in 1983, coordinated by C.D. Keeling.
The second meeting, the "International Conference on Atmospheric CO2" took place in Kandersteg, Switzerland, in September 1985. It was sponsored by the Commission on Atmospheric Chemistry and Global Pollution of the International Association of Meteorology and Atmospheric Physics. About 60 scientists attended. In addition to atmospheric measurements of CO2 and its isotopic ratios, attention was given to new measurements of historical CO2 in ice cores, and more emphasis on the terrestrial biosphere, air-sea gas exchange, and 3-dimensional transport modeling. A series of papers was published as a special issue in Tellus, 1987, with C.D. Keeling and U. Siegenthaler as guest editors.
The Third International Conference on Analysis and Evaluation of Atmospheric CO2 Data Past and Present was held in Hinterzarten, Germany, in October, 1989. It was sponsored primarily by the University of Heidelberg and the WMO. There were about 120 participants. Exciting new ice core data were presented. The evidence for a large carbon sink on land in the northern hemisphere was first presented. In addition to the subjects of the second meeting, new attention was given to ocean biota, and an entire session was devoted to the modeling of oceanic CO2 uptake and transport. Papers were published in a special issue of Tellus, 1991, with I. Levin and P. Tans as guest editors.
The Fourth International CO2 Conference was held in Carqueiranne, France, in September 1993, and sponsored by WMO and several French organizations. About 200 scientists attended the meeting and more than 150 papers and posters were presented. There were sessions on atmospheric measurements, oceanic measurements, process models and carbon transport models in both environments, terrestrial observations and ecosystem models, ice core data, and isotopic ratio observations. An important issue during the conference was the observed slowdown of the rate of CO2 accumulation in the atmosphere observed in 1992 and 1993. Papers were published in a special issue of Tellus, 1995, with I. Fung and L. Merlivat as guest editors.
The Fifth International CO2 Conference took place in Cairns, Australia, in September 1997. It was organized by the Commonwealth Scientific and Industrial Research Organisation, Australia, and sponsored by the WMO, with various other organizations making a financial contribution. About 200 scientists attended, and about 200 oral and poster presentations were given. The new measurements of atmospheric oxygen played an important role at the meeting. Results of measurements of terrestrial carbon fluxes through the eddy covariance method were presented for the first time. There were sessions on atmospheric measurements, including isotopic ratios, and inverse models (which deduce sources and sinks from observed concentration patterns), on oceanic measurements and models, on terrestrial land use as well as fertilization of the biosphere, on ecosystem models, on ice core measurements, carbon cycle synthesis models, and a little about future CO2 projections. Papers were published in a special issue in Tellus, 1999, with R. Francey, M. Apps, F. Joos, D. Schimel, and A. Watson as guest editors.
The Sixth International CO2 Conference took place in Sendai, Japan, in October 2001. It was organized by Tohoku University and sponsored by the WMO and various Japanese organizations, with financial contributions from a number of Japanese corporations. There were approximately 300 oral and poster presentations, by about the same number of attendees. The meeting witnessed an enormous expansion in the use of inverse models in both the atmospheric and oceanic domains, reflecting the continuing increase in the density of observations, as well as the rapidly increasing capabilities of computers. Remote sensing, including the potential of direct retrievals of atmospheric CO2 from space, played a much bigger role than in previous conferences. Of course, all major topics of previous conferences continued to receive attention. Papers were again published in a special issue of Tellus, 2003, with P. Tans, T. Nakazawa, and H. Yoshikawa Inoue as guest editors.
Format of the meetings
All oral sessions have been plenary in every conference, with the length of the oral presentations 30 minutes at the Cairns meeting, and 20 minutes at the Sendai meeting, except for invited presentations that were given 40 minutes in Sendai. The advantage of plenary sessions is that all participants have an excellent opportunity to stay abreast of developments outside their own specialty. In Cairns all posters stayed up for several days, in Sendai for one day because of lack of space. In the latter case the poster sessions highlighted different topics on different days. There has always been a generous amount of time for poster sessions completely separate from the oral sessions.
Talks
Posters
| Title | Presenter | Description |
| Observational Data Screening Technique Using Transport Model and Inverse Model in Estimating CO2 Flux History | Takashi Maki | We have developed a new data screening technique using an atmospheric transport model and an inverse model. Using this technique, we can use original (not smoothed) observational data for the inversion method. This means that we can enlarge the number of observational data for inversion method and we can estimate carbon dioxide (CO2) flux history consistently in long period in accordance with the number of the observational sites. |
| A Bayesian synthesis inversion of the global carbon cycle: How observations reduce uncertainties | Daniel Ricciuto | Global-scale observations of CO2 concentrations and fluxes are assimilated by a simple carbon cycle model in order to produce full probability density functions of 4 key carbon cycle parameters using the Markov Chain Monte Carlo technique. Future sink uncertainty is estimated under the S550 stabilization scenario, and the utility of additional flux observations to reduce sink uncertainty is analyzed. |
| A Paleo Perspective on the Ocean's Role in the Carbon Cycle | David M. Anderson | The ocean has a dominant influence on carbon dioxide in the atompshere, and ocean processes change slowly (centuries to thousands of years). Paleo reconstructions of the large natural changes that have occurred in the past provide a way to understand the ocean's role. |
| Air-Sea Flux of Carbon Dioxide in the Costal Eastern Pacific | Gernot Friederich | This project seeks to first quantify and then understand the magnitude, spatial pattern, and variability of air-sea carbon dioxide (CO2) flux in the costal waters of the eastern Pacific. |
| Carbon isotope evidence for the latitudinal distribution of air-sea gas exchange | N. Y. Krakauer, J. T. Randerson, F. W. Primeau | The air-sea gas exchange rate is important for modeling and verifying ocean CO2 uptake, but remains subject to considerable uncertainty. The widely assumed quadratic or cubic dependence of the exchange rate on windspeed together with the latitudinal pattern of mean windspeed implies that exchange is much faster at high compared with low latitudes. This should affect the pattern of ocean uptake of bomb carbon-14 as well as the rate of decline of and latitudinal gradients in atmospheric Δ14CO2. We evaluate the constraints on the windspeed dependence of the exchange rate offered by available isotopic measurements, discuss the major uncertainties, and suggest observational strategies to reduce these uncertainties. |
| Continuous In Situ Measurements of Atmospheric O2 and CO2 at Harvard Forest | Mark Battle | Simultaneous and continuous measurements of O2 and CO2 made in the air around terrestrial ecosystems have the potential to improve our understanding of the biogeochemistry of the ecosystem, and may reduce uncertainties in estimates of terrestrial carbon uptake derived from atmospheric O2 measurements. Following the design of Stephens et al. [2001], we have constructed an instrument that performs continuous in situ measurements of atmospheric O2 and CO2 concentrations. We present design and performance data, along with preliminary results from a deployment at the Environmental Measurement Site at Harvard Forest in central Massachusetts. |
| Effect of Enriched CO2 on Rice Under Open Top Chamber (OTC) Condition in Nepal | Kishore Sherchand | Rice is the most important crop for majority of farmers of Nepal both in terms of it contribution to the national economy and employment. The objective of this study was to evaulate the effect of the elevated CO2 on rice crop under open top chambe (OTC) condition. |
| Impact of elevated CO2 on the food production of Nepal | Kishore Sherchand | The three cereal crops rise, maize and wheat cover over 75% of the total food production of Nepal. All the three crops rise, maize and wheat showed increased yield with doubling the CO2 level but also showed a declining tendecny at the elevated temperature. Among the three crops, maize was the most affected by the rise in tempuerature although increased CO2 level could increase the crop yield. |
| Interannual variability in Atmospheric Potential Oxygen | RC Hamme, RF Keeling, WJ Paplawsky | pdf file of Hamme, Keeling and Paplawsky poster for ICDC7. |
| Measurements and Models of Atmospheric Potential Oxygen (APO) | Mark Battle | Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined to form the tracer Atmospheric Potential Oxygen (APO), reflecting primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. [1998], we present a new set of APO observations including shipboard collections from the equatorial Pacific. Our data show a smaller interhemispheric gradient than observed in past studies and a substantial APO maximum around the equator. Following a modeling approach developed by Gruber et al. [2001], we compare these observations with APO fields generated by a set of oceanic and atmospheric models. Overall, our model results agree well with observations, but small differences suggest that modeled north-south transport may be too vigorous, air-sea fluxes may be too coarsely resolved in some regions, and seasonal trapping of surface fluxes may be excessive in some model locations. |
| Synthesis of Top-Down and Bottom-Up Scaling of Regional Terrestrial Carbon Dioxide Fluxes | Ankur R Desai | Regional exchange of CO2 in the upper Midwest, USA was investigated with several different bottom-up and top-down methods. With careful calibration, encouraging consistency is seen from several independent regional flux estimates. |
| Synthesis of Top-Down and Bottom-Up Scaling of Regional Terrestrial Carbon Dioxide Fluxes | K.J. Davis, A.R. Desai, and coauthors | An experiment has been conducted to determine regional-scale fluxes using both top-down (ABL budgets and atmospheric inversions) and bottom-up (eddy covariance flux tower aggregation) approaches. The results show reasonable convergence among methods, but also show differences in fluxes among forest stands that are significant and not readily captured by existing land cover products. |
| Using continental, continuous CO2 observations in a time-dependent global inversion to infer regiona | Martha Butler | Simulation of mid boundary layer CO2 mixing ratios from observations routinely collected at flux tower sites (tower top well-calibrated CO2 mixing ratio, CO2 flux, sensible heat flux and temperature), providing a means of extending the CO2 measurement to improve the density of continental measurements in the global network. |
| Using Inverse Modelling to Investigate Potential IR Measurement Strategies for Constraining the Australian Carbon Cycle | NM Deutscher; RM Law; DWT Griffith; GW Bryant | This study employs a top-down approach to better understanding the carbon cycle. Fourier Transform Spectroscopic trace gas measurements are combined with inverse modelling. Possible measurement locations and strategies in the Australian continent are investigated. This is done by simulating data for the potential measurement locations, and using this simulated pseudodata in inversion studies to determine the additional constraint applied to the source estimate uncertainty in Australia and nearby regions. |