Assessing Impacts, Vulnerability, and Adaptation to Global Changes
As the scientific understanding and forecasting of global change improves or transforms, there is a continuing need to review and revise what we know about the human consequences of these changes and the ability of social systems to adapt to them. It also important to monitor the shifting vulnerability of human systems as political, technological, and economic trends and policies alter the conditions in which societies experience global change.
For example, improved forecasts of El Niño and better regional estimates of climate associated with global warming can be linked to updated assessments of the human impacts of climate variability and change. Demographic shifts and economic restructuring have dramatically altered the vulnerability of many regions to water supply variations and natural hazards. Adaptations such as irrigation and plant breeding are changing the ability of agricultural systems to cope with droughts.
Impact, vulnerability, and adaptation assessments can greatly benefit from new methods and data availabilities. For example, impact assessments can incorporate improved analyses of climate variability, uncertainty, and local geographical differences. Fresh datasets (such as decadal population and agricultural censuses, satellite imagery) within geographic information systems can enhance and update assessments.
RELATION TO USGCRP PRIORITIES
Focused research efforts on the consequences of global change can support the wider needs of the USGCRP in the following ways:
by providing current and policy-relevant information on the impacts of various global change scenarios at regional scales;
by contributing to assessments that integrate a range of scientific data and models with information on social impacts, vulnerabilities, and adaptations and their interaction with mitigation efforts;
by providing insights into the ways in which (seemingly unrelated) policy decisions and societal conditions are changing the vulnerability of human systems to global change;
by improving the ability to assess the societal impacts of interannual climate variability (such as El Niño) and the likely effect of improved forecasts and other responses; and
by providing feedback to the modeling community as to the most appropriate and urgent data outputs (variables, time and space scales) for assessing the human impacts of global change.
TIMELINESS OF EFFORT
This research priority is timely because of its potential contribution to the USGCRP's increasing emphasis on consequences, sustainability, and integrated assessment. There is a considerable community of researchers with experience in assessing the impacts of climate change. This community can be supported in work to improve methods, datasets, and models that can use the results of new generations of climate models (both general circulation and mesoscale).
Research on impacts, vulnerability, and adaptation to global changes can yield:
improved and more regionally detailed assessments of the impact of climate change on socioeconomic and ecological systems using the most recent results of general circulation climate models, mesoscale models for global warming, and information on the characteristics of interannual climate variability;
vulnerability assessments of the ability of resource and human systems such as forestry, agriculture, cities, and industry to anticipate and respond to global changes (taking into account the ways in which major nonenvironmental changes such as population growth, institutional and economic transformations, and technical developments are altering the vulnerabilities of individuals, communities, and regions to environmental change and variation); and
improved information for valuing the consequences of global change, incorporating estimates of uncertainty in decision processes and providing key transfer functions (e.g., the relationship between temperatures and health or water resources) for economic and social impact assessments.
This research should build on developments in remote sensing, geographic information systems, and the availability of large social science datasets. It should emphasize comparative research to take into account institutional differences, such economic processes as the regionally redistributive effects of global change, and shifts in comparative advantage, all of which must be considered for good integrated assessments.
Several recent studies illustrate the type of research that can contribute to the USGCRP impact assessment activities. Recent suggestions for improved impact assessment methodologies include those of Malone and Yohe (1992), who provide a framework for integrated regional assessment based on the MINK study; Robock et al. (1993), who describe new methods of generating impact analysis scenarios from general circulation model output; and Downing (1991) and Liverman (1990), who develop techniques for vulnerability assessment.
The MINK study used an analog climate from the 1930s to examine the impacts of climate change in the Midwest-Great Plains region (Missouri, Iowa, Nebraska, and Kansas) (Rosenberg et al. 1993). The study was integrated in that it looked at several sectors—agriculture, forests, water, and energy—and assessed the interindustry linkages and interacting impacts with a model of the regional economy. The effects of contemporary and future adaptations to climate (such as improved plant varieties) as well the agricultural impacts of higher CO2 levels were assessed in the study. Several elements of the MINK framework could be applied to more complex regions and climate scenarios.
Another example of integrated impact assessment is the recent study by Rosenzweig and Parry (1994) of the potential effects of climatic change on world food supply. This study used a range of global warming scenarios to assess changes in crop yields and potential adaptations in 18 countries and integrated the impacts through a world food model. Linked models are also being used in an integrated assessment of the impacts of climate warming in the Mackenzie River Valley of northern Canada (Lonergran, DiFrancesco, and Woo, 1993; Cohen, 1992).
RELATION TO INTERNATIONAL RESEARCH
This research effort would support international efforts at assessing global change impacts and vulnerabilities through institutions such as the Intergovernmental Panel on Climate Change and regional research efforts such as the Inter-American Institute (IAI). It might also support the emerging HDP activity on Environmental Security and Sustainable Development.
This research initiative can advance through both investigator-initiated and institutionally coordinated research. Some of the research could be coordinated
through USGCRP contributions to international efforts such as the IAI and the proposed center for climate prediction. Links between physical scientists and social scientists are important to ensure that investigators are using the most relevant and up-to-date data and model results. Although agencies with responsibilities in specific sectors (e.g., water, agriculture) might sponsor related research, coordination will be required to further the potential of integrated assessments.