An Introduction to Climate Change Assessments
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The science associated with climate change is increasingly improving our understanding of the potential climate change and their effects on ecosystems, economies, and social systems (1,2,3,4,5). Climate change assessments serve as important syntheses of this science, and they provide information and context for management and policy decisions. Climate change assessments can focus on understanding what climate changes are occurring and what is causing them, the consequences of climate change, or the options for responding to climate change.
Critical to developing an assessment is identifying key questions that express the information needs of managers and decision makers. Assessments vary widely depending upon the geographic area, topic of interest, and need for specific types of information. Assessments may be produced periodically or for one specific need, and some assessments are motivated by legal requirements. Assessments can be conducted by international organizations, federal, state or city institutions, and non-governmental organizations. Most assessments involve an interdisciplinary team of experts and often engage a larger group of stakeholders and potential users of the information.
This topic paper organizes climate change assessments into three main assessment types: impact assessments, vulnerability assessments, and natural resource assessments. These have different purposes and often contain different information. While there are areas of overlap between the types of assessments, it can be much easier to gather and synthesize information once the assessment type has been determined. The intents, contexts, and scientific review processes for each of these assessment types are also described.
Climate Change Impact Assessments
Climate change impact assessments identify and quantify the expected impacts of climate change. These assessments synthesize the current scientific knowledge of the expected effects of climate change on a focus area, such as a resource, economic sector, landscape, or region, for decades to centuries into the future. An analysis often begins by looking at changes to temperature, precipitation, and other climatic variables under multiple scenarios of greenhouse gas emissions (6). The analysis then considers the potential impacts on the focus area as a result of the anticipated changes. This synthesis is typically conducted by an interdisciplinary team which may also engage with stakeholders on the specific policy or management needs. The assessment team draws information from the available literature, relevant research and modeling results, and the expertise of scientists.
Climate Change Vulnerability Assessments
Vulnerability assessments go beyond impact assessments to determine a system's sensitivity and ability to adapt to climate change and may be used in place of or in addition to climate change impact assessments. Vulnerability is defined as the degree to which a human or natural system is susceptible to, and unable to cope with, the adverse effects of climate change, including associated climate variability and extremes (1,2). A system's vulnerability is related to the character, magnitude, and rate of climate change and variation that it is exposed to, as well as the system's sensitivity and capacity to adapt. Climate change vulnerability assessments generally quantify the sensitivity of a particular system to climatic changes (including increased climate variability), the degree to which a system may be exposed to changes in climate, and the potential adaptive capacity of the resource, sector, or landscape or region. Given concerns about the effects of climate change on natural and human systems, vulnerability assessments are increasingly common. The information and methods used to create these assessments vary widely across resources and sectors.
Climate Change in Natural Resource Assessments
Natural resource assessments generally describe the current condition of specific natural resources, and assess factors that are affecting the resource, with the goal of providing timely, relevant, and accessible information for decision makers and policy makers. In addition, some resource assessments may also quantify how those factors will affect the resource into the future. These assessments are often part of a planning process where management for the next several years is to be determined. Climate change is now an additional dimension that is being included in many natural resource assessments, such as the Forest Service's Resource Planning Act (RPA) Assessments and the Ecoregional Assessments prepared by the Bureau of Land Management. Because these existing natural resource assessments reflect the individual management agencies and organizations objectives and needs, current approaches to adding climate change consideration into these assessments vary widely.
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Joyce, Linda A.; Janowiak, Maria K. (July, 2011). Climate Change Assessments. U.S. Department of Agriculture, Forest Service, Climate Change Resource Center. www.fs.usda.gov/ccrc/topics/assessments/introduction-to-assessments
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