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The ultimate products of these studies will be products for use by policymakers and decision-makers, as well as by all global and climate change stakeholders and interested members of the general public. The studies aim to answer questions posed by the Administration, which were incorporated into the statement of task for the NAS study. Some examples of key suggested products include:

As previously stated, the proposed studies should produce products for policymakers and decision makers. For example, studies of the amount of carbon being taken up by the North American biosphere will provide critical input to discussions of carbon credits. Studies of the regional impact of changes in hydrology will provide critical information to regional water managers on expected changes in water availability. However, to develop these decision support products we will need critical intermediate products: studies of key processes that will reduce uncertainty, observations of priority components of the climate system, and improved global climate models. For example, climate models that accurately include the role of aerosols and water vapor in climate forcing and feedback mechanisms should substantially improve our ability to determine the relative importance of reducing aerosol emissions as compared to CO2 and methane emissions. Coupling these model studies with studies of regional processes will also provide much clearer evidence of the impact of climate change on precipitation and therefore on agriculture, water availability and other impacts related to precipitation.

Models of future climate assume certain scenarios of future human activity as inputs. At present the scenarios being used by the IPCC do not include all of the important particulates aerosols that affect climate. Extending the emissions scenarios to include this wider range of relevant anthropogenic inputs is essential and IPCC has called for such research on scenarios. The scenarios will be important determinants of the perception of the problem to be solved.

The most significant limitation of the current set of scenarios is the lack of information on the relative likelihood of the scenarios. If the objective is to reduce the range of uncertainty, finding a technically valid way to assess the plausibility or likelihood of both the individual scenarios and ranges of scenarios is very important. This is an area needing creative initiatives, because most existing tools have well recognized technical flaws.

Carbon is the basis for the food and fiber that sustain human populations. It is the primary energy source that fuels human economies, and it is a major constituent of the greenhouse gases accumulating in the Earth's atmosphere that are the basis for potential changes in global climate. Carbon dioxide (CO₂) and methane (CH₄) concentrations in the atmosphere are now higher than they have been for over 400,000 years. Combustion of fossil fuels and land clearing (reducing forests, grasslands and vegetative cover) during the past 150 years are the sources for most of this increase. Approximately half of the carbon dioxide released to the atmosphere annually by human activities remains in the atmosphere. The other half is taken up by trees and other plants on the land, and by plants and chemical processes in the ocean. Since trees, plants, soils, and the ocean also release carbon to the atmosphere as part of their overall functioning in the Earth's carbon cycle, it is of great importance to quantify the size, power, and longevity of these sinks. Active management of the carbon cycle offers opportunities to offset carbon emissions by enhancing the storage of carbon in plants, soils, and forest products as well as in the oceans, although the time scales over which these practices can remain effective are unknown. The nation and the world are entering an era in which carbon cycle issues lie at the core of several policy debates centered on future climate change and its consequences for humans.

One of the major challenges for global climate models is the accurate characterization of the multiple processes of the ocean and atmosphere that are important for projecting changes in climate. These processes can alter or amplify the effects of greenhouse gases. In the geologic past they have also been characterized by abrupt changes that had far-reaching effects on climate.

Societies and ecosystems are often most vulnerable, and least resilient, to the environmental stresses produced by extreme weather and climate events. The need for improved information on such events, particularly at regional and local scales, is one of the highest priorities for users of climate information. Major droughts, floods, heat waves, hurricanes, and storm surges are examples of extreme events that have major economic and social impacts, and whose frequencies, intensities, and geographical distributions may change in the future.

Deliverables produced under the initiative are expected to include:

Air pollution continues to be a widespread public health and environmental problem in the United States. The evaluations of effects of climate change on air quality will provide baseline information about ozone and particulate matter under conditions of climate change that will be used to derive health effects estimates. The initiative will also produce decision-support tools to help urban air quality managers determine whether climate change will make it more or less difficult for them to meet ambient air standards, and to evaluate what opportunities exist to build resilience to these future changes.

Water quality is already affected by factors other than climate change (e.g., nutrients, sediments, microbial pathogens, pesticides, and other toxic pollutants) and alterations in freshwater habitats, stream flow, and water temperatures. These influences on water quality may be exacerbated or ameliorated by climate change, climate variability or land-use change. The results of this initiative will assist water quality managers in urban and metropolitan areas to evaluate the extent to which climate change will make it easier or more difficult for them to maintain water quality as the climate changes, and to identify opportunities to adapt to change.

One expected benefit of these initiatives is improved capacity to reduce damages associated with extreme weather events and to incorporate understanding of extreme events into our broader concepts of sustainable economic development. We envision contributions to disaster relief efforts, where there is considerable interest in moving from after-the-fact aid to the pre-positioning of plans and resources. Early warning systems, and public and private sector urban, water, and land use planning are also clients for the products of this effort. This initiative would also provide additional means for operational climate forecasters and information providers to evaluate their products and ensure that their investments are targeted on matters of highest concern to vulnerable populations.

Decision-support tools will also be developed to help public health officials determine appropriate adaptive response strategies, and evaluate the extent to which these responses at the societal or individual level could reduce the impacts of climate change on human health and increase the resilience of the public health care system to climate change.

To fully understand the implications of improved climate change understanding requires that that knowledge be integrated with other knowledge, particularly with regard to the economy, and the breadth of forcing functions. Without a full systems analysis context it will be impossible to realize the full benefits of this research.

Comprehensive modeling is a central and critical element of climate research. Over the last two decades, the climate research community has sustained significant progress in the continuing development and application of climate models. Nevertheless, the current organizational structure of the U.S. modeling effort has not fully supported the delivery of model products that are especially important for making climate simulation and prediction more usable and applicable to the broader research, assessment and policy communities. The U.S. agencies have initiated planning and activities towards forming the basis for a longer-term solution that maintains the pace and progress of the basic research enterprise while simultaneously creates a path for the rapid exploitation of new knowledge in model products.