The First GAIM Science Conference was held on Sept. 24-29, 1995 in Garmisch-Partenkirchen, Germany, and consisted of 5 days of oral and poster sessions. The Goal of the Science Conference was to provide a venue for the dissemination of preliminary results for the purpose of steering subsequent research efforts toward reliable prognostic biogeochemical models. The conference was co-sponsored by the German National IGBP Secretariat in Berlin, and supported by NSF, ISF, German National IGBP, START, ENRICH, and the German Development Foundation. GAIM office base support was provided by EPA.

The Science Conference focused on papers in the areas of global data analysis and assessment, modelling of biogeochemical systems and their relationship to physical climate and hydrologic systems, and interpretation of current trends as indicated by global databases and model results for extrapolation with regard to future global change. Oral and Poster session topics were grouped by time periods, including "Paleo" (<20k yrs), "Historical" (<2k yrs), "Contemporary" (<20 yrs), and "Future", with an additional session concerned with global systems integration.

Speakers introduced each new topic to establish a basis for posters, and discussion. The format of the conference place a heavy emphasis on poster presentations and informal discussion. Posters were left on display throughout the entire week, although each day focused on one time period. Ample time was left open for individual discussions, meetings, and model result comparisons.

Papers emerging from the GAIM Science Conference will be published in a special issue(s) of Global Biogeochemical Cycles through the normal peer-review process.

A brief synopsis of the meeting is as follows:

MONDAY - The "Paleo" Era

The concern with future Earth system responses to large perturbations in atmospheric composition and climate makes it important to exploit the recent geological record as studied by the IGBP project Past Global Changes (PAGES). The paleo record in fact provides the only means to test such models under conditions (in the past) that are as different from present as the conditions expected to apply in 50-200 years' time.

Hans Oeschger made the first presentation in plenary session with challenges for GAIM from the standpoint of PAGES. Subsequent presentations by J.-C. Duplessy and W.R. Peltier focused on glacial-interglacial variability and Dansgaard-Oeschger oscillations. Additional oral presentations regarding CO2, Ocean circulation, Methane, Orbital variations, Lake records, and model simulations set the stage for a lively discussion centered around the poster sessions.

TUESDAY - The Historical Era

The historical era (<2,000 yrs) is the time during which human activities became a significant forcing factor in global change. The earliest influences were those of land use changes, as agriculture led to deforestation, and diversion of surface water for irrigation led to hydrologic changes on basinal scales. Steadily increasing fossil fuel emissions beginning in about 1860 are thought to have caused most of the observed increase in atmospheric CO2 concentration. At present, however, we are unable, by accounting for other sources and the redistribution of carbon within its global cycle, to relate observed increases to estimates of past fossil fuel emissions. This questions the veracity of estimates of future CO2 increase and drives a substantial effort to understand carbon cycle responses to human activities over the past several centuries. The causes since the industrial revolution of increases in other greenhouse gases such as CH4 and N2O are less certain, primarily because changes in the distributions and magnitudes of their sources are poorly known.

Oral presentations focused on the Carbon cycle, with talks on Nutrient regulation, Atmosphere-biosphere exchange, atmospheric trace chemistry, Ozone (presented by P. Crutzen, recent Nobel Laureate), ocean carbon, and models of terrestrial ecosystem dynamics and CO2 fertilization. Poster presentations were much more detailed and varied, including such topics as deforestation documentation, the effect of irrigation, biomass burning, sea level changes, and the budgets of P, N, and S.

WEDNESDAY A.M. - Global Systems Integration

This special session departed from the temporal sequence structure of the conference, and focused on the interactions and feedbacks between biogeochemical subsystems (e.g. atmosphere, ocean, terrestrial ecosystems, etc.) and integration into whole-Earth models.

Oral presentations considered the physical climate subsystem, tropospheric chemistry, linking the terrestrial biosphere and atmosphere, dynamic vegetation, and ocean CO2. Posters were presented on such topics as ecosystem dynamics, the hydrologic cycle, biome models, ocean circulation, ocean-atmosphere-ecosystem coupling, and preliminary integrative Earth system models.

WEDNESDAY P.M. - Integrating the Developing World in Global Change Modelling

A special session focused on the concerns of START and ENRICH was held on Wednesday afternoon. GAIM recognizes the importance of linking regional research programs into the global research questions on which it focuses. Moreover, there is a growing realization of the importance of tropical and subtropical regions in the study of global environmental changes and data requirements to global change issues. The success of GAIM depends on gathering expertise as well as data from the entire planet.

Current modelling results were discussed as well as future global data needs to encourage collaboration and involvement with ongoing international modelling efforts. In addition, many issues emerged which served to better identify the resource and other needs of scientists from developing countries. It is clear that these needs must be fulfilled so that they can more effectively gather, assess, and integrate global change data from their regions. In many countries, leading sicentists do not have even the most basic computation or communication facilities which would make involvement in international global change research programs feasible.

Presentations were made by Berrien Moore (GAIM Chair), Peter Tyson, (START Chair-designee), Anwer Ghazi (ENRICH Director), Wandera Ogana (Kenya IGBP Secr. & African GAIM working group coord.), and Carlos Nobre (GAIM Task Force Member from Brazil). The session ended with an open discussion of links between issues of local scientific interest in developing countries (e.g. land use change and sustainability) and global scientific issues, and resource requirements and funding mechanisms for enhancement of global change research in developing countries.

THURSDAY - The Contemporary Era

The Contemporary Era (the period from immediate past to immediate future) provides the greatest availability of data over the immediate past and the easiest task of validation over the immediate future. Further, now is a time of rapid change, representing the most rapid change available to study over the last millennium. The period of 20 years is the shortest time scale available to look at for this "decades to centuries" change.

This session highlighted papers directed at the global budgeting and modelling of the present- day state of the major biogeochemical cycles. Oral presentations introduced the issues of the effects and interpretation of atmospheric CO2 variations, greenhouse gases, N and O, Ocean carbon, terrestrial carbon model validation, deforestation/desertification, hydrology, and atmospheric aerosols. Posters included presentations on the interactions of climate and ecosystems, Net Primary Productivity, Satellite observations, and Remote sensing databases.

FRIDAY - The Future

The purpose of the "Future" session of the Science conference was to bring forth preliminary results and discussion of prognostic biogeochemical models. The capability of biogeochemical models to predict future changes in the Earth system is dependent on the understanding of past global changes. For instance, by comparing "contemporary" rates of change to those of older and longer time periods, prognostic models may more accurately predict magnitudes of change in Earth systems and subsystems. While prognostic biogeochemical models are presently in a very primitive stage of development, comparison of the models will lead to better identification of data needs, shortcomings in our understanding of rates and interactions between changing subsystem components, and sensitivities of models to uncertainties in each subsystem component as well as component interactions.

In this session, oral presentation discussed the observational search for predicted temperature changes, coupled ice-atmosphere-ocean models, oceanic radiocarbon, and finally, the link between global change and human society. Posters considered the effects of doubled CO2, the desirability for "optimistic" predictions, projection of various subsystem scenarios, and future agricultural interactions with climate and natural ecosystems.

The abstracts from the GAIM Science Conference are available on the GAIM home page for dowloading. Please note this is a large file (623K) and may take some time over slower connections. Alternatively, they can be requested in hard copy from the GAIM Task Force Office:

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