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Updated 16 September 2008

Climate Variability and Change (Including Climate Modeling)
USGCRP Program Element



Climate Variability and Change


Recent Accomplishments

Near-Term Plans

Archived News Postings [June 2000 - July 2005]

Related Sites

Calls for Proposals

CCSP / USGCRP Climate Variability and Change Working Group Members

For long term plans, see chapter on Climate Variability and Change of the Strategic Plan for the Climate Change Science Program (2003) posted on CCSP web site

Climate Variability and Change imageRecognizing that the climate system operates seamlessly across a wide spectrum of time scales, CCSP-supported research encompasses both short-term climate variability and longer term climate change. Addressing the interaction of climate processes across time scales poses challenges not only in designing observation systems to monitor the climate system adequately, but also in constructing models that can properly reproduce its past behavior, and confidently project its future behavior. Earth system models, in combination with global Earth observations, must produce internally consistent maps of atmospheric, oceanic, land surface, and ice conditions both in near-real-time and retrospectively. These maps, or "analyses," will provide decisionmakers with tools to visualize the evolving state of the full climate system over the entire planet, and researchers with the ability to better explain observed changes in the climate system.


Strategic Research Questions

4.1To what extent can uncertainties in model projections due to climate system feedbacks be reduced?

4.2. How can predictions of climate variability and projections of climate change be improved, and what are the limits of their predictability?

4.3. What is the likelihood of abrupt changes in the climate system such as the collapse of the ocean thermohaline circulation, inception of a decades-long mega-drought, or rapid melting of the major ice sheets?

4.4.  How are extreme events, such as droughts, floods, wildfires, heat waves, and hurricanes, related to climate variability and change?

4.5.  How can information on climate variability and change be most efficiently developed, integrated with non-climatic knowledge, and communicated in order to best serve societal needs?

See Strategic Plan for the U.S. Climate Change Science Program, Chapter 4, for detailed discussion of these research questions.

To address fundamental CCSP goals, the climate variability and change (CVC) element emphasizes research to improve descriptions and understanding of past and current climate, as well as to advance national modeling capabilities to simulate climate and project how climate and related Earth systems may change in the future. Research under this element encompasses time scales ranging from short-term climate variations of a season or less to longer term climate changes occurring over decades to centuries. The CVC element places a high priority on improving understanding and predictions of phenomena that may cause high impacts on society, the economy, and the environment. Examples include identifying the relationships between variations and changes in climate and hurricane activity; improving understanding and predictions of droughts; increasing understanding of and capabilities to predict the El Niño-Southern Oscillation and its attendant impacts; identifying processes that may produce rapid or accelerated climate change; and improving capabilities to observe, understand, and model Earth system components that have high societal and environmental relevance, including sea ice, glaciers, ice sheets, and sea level. Addressing these fundamental issues requires an integrated approach toward understanding the interactions and feedbacks among the different components of the Earth system, including the atmosphere, ocean, land, cryosphere, and biosphere.

Gulf Of Alaska SEDIMENT

CVC research is placing increasing emphasis on understanding and modeling the links and feedbacks among climate system components. Considerable advances have been made in this area through the development and application of Earth system models, including several that were used extensively in the recently completed Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (see introductory chapter of this report). CVC research is also emphasizing the development of new capabilities to link Earth system models together with Earth system observations to produce internally consistent maps of atmospheric, oceanic, land surface, and ice conditions that are called “Earth system analyses.” These analyses will help us to understand and explain past and current climate conditions, and provide decisionmakers with new tools to track how the Earth system is evolving in time over the entire planet.

Research within the CVC element focuses on two broad, critically important questions to society defined in the CCSP Strategic Plan:

  • How are climate variables that are important to human and natural systems affected by changes in the Earth system resulting from natural processes and human activities?
  • How can emerging scientific findings on climate variability and change be further developed and communicated in order to better serve societal needs?
  • More specifically, CVC research addresses the five strategic research questions listed at the beginning of this chapter to achieve the milestones, products, and payoffs described in the CCSP Strategic Plan. Cooperative efforts involving CCSP agencies have led to significant progress in addressing the strategic questions articulated in the CVC chapter of the CCSP Strategic Plan. The following section highlights some of the major scientific advances achieved during this past fiscal year.


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