What is IPCC?
What are scenarios and why are they used?
What are UCAR, NCAR and UOP?
What is the NCAR GIS Initiative?
What is NCAR's involvement in IPCC?
What is the CCSM?
What version of the CCSM is being used to generate climate change scenarios for the IPCC?
What are the CCSM components?
What is the spatial resolution of the climate change datasets produced by the CCSM?
What data one can download from this website?
What is downscaling?
What is the spatial resolution of downscaled CCSM-3 projections for the contiguous USA?
Where can I get climate change data produced by other climate models?
Where can I learn more about climate change impacts research?

What is IPCC?
The Intergovernmental Panel on Climate Change (IPCC) has been established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. IPCC produces assessment and special reports on climate change and related topics. The 4th Assessment Report (AR4) on Climate Change was released in 2007 and is available through the IPCC web site. In late 2007, participants in all the IPCC assessments since 1990 shared in the Nobel Peace Prize.

What are scenarios and why are they used?
Future greenhouse gas emissions are the product of very complex dynamic systems, determined by driving forces such as demographic development, socio-economic development, and technological change. Their future evolution is highly uncertain. Scenarios are not specific predictions or forecasts of future climate. Rather, scenarios are plausible alternative futures. Each scenario is an example of what can happen under particular assumptions on use of fossil fuel and other human activities. Scenarios assist in climate modeling, help to examine potential climate change and explore vulnerabilities of humans and ecosystems under a changed climate. For more information, visit IPCC special report on Emissions scenarios.

What are UCAR, NCAR and UOP?
The University Corporation for Atmospheric Research (UCAR), National Center for Atmospheric Research (NCAR) and UCAR Office of Programs (UOP) are part of a collaborative community dedicated to understanding the atmosphere and the interconnected processes that make up the Earth system, from the ocean floor to the Sun's core. The National Center for Atmospheric Research and the UCAR Office of Programs provide research, facilities, and services for the atmospheric and Earth sciences community. NCAR and UOP are managed by the nonprofit University Corporation for Atmospheric Research. To learn more about UCAR, NCAR and UOP visit UCAR's web site.

What is the NCAR GIS Initiative?
The NCAR GIS Initiative is an interdisciplinary effort to foster collaborative science, spatial data interoperability, and knowledge sharing with GIS. The main goal of the GIS Initiative is to promote and support the use of GIS as both an analysis, and an infrastructure tool in atmospheric research and to address broader issues of spatial data management, interoperability, and geoinformatics within the geosciences. Working in collaboration with other NCAR strategic initiatives, divisions, and UCAR programs, initiative supports variety of science projects at NCAR, improves compatibility of atmospheric data sets with GIS tools, and creates bridges between atmospheric, geo- and social sciences. In 2004, the GIS Initiative launched ?GIS Climate Change Scenarios? project (this website) to serve a wide community of GIS users interested in global climate change. For more information about GIS Initiative or this portal, contact our staff.

What is NCAR's involvement in IPCC?
As one of the world?s leading climate modeling and research centers, NCAR is a strong supporter of the IPCC scientific assessment process. NCAR scientists have served as lead and contributing authors in each of the four full IPCC assessment reports (1990, 1995, 2001, and 2007) as well as a number of special reports and technical papers that have focused on more specific issues. NCAR climate modeling and process study research has contributed to the peer-reviewed scientific literature that forms the basis of the IPCC?s work. 40 NCAR staff served as coordinating lead authors, lead authors, reviewers, or contributors on the 2007 IPCC reports, with additional staff providing technical support. More information about NCAR's contribution to IPCC is available here.

What is the CCSM?
The Community Climate System Model (CCSM) is a community-wide effort led by the National Center for Atmospheric Research (NCAR) and is a key component of the National Science Foundation program on Climate Modeling, Analysis and Prediction. Composed of four separate models simultaneously simulating the earth's atmosphere, ocean, land surface and sea-ice, and one central coupler component, the CCSM allows researchers to conduct fundamental research into the earth's past, present and future climate states. The most recent version, CCSM-3, was released in 2004. The CCSM project played a major role in the IPCC AR4 through the completion and analysis of an extensive series of emission scenario experiments. A subset of CCSM model runs is available through this portal.

What version of the CCSM was used to generate climate change projections for the IPCC AR4?
CCSM3.0, the most recent release of the global coupled climate model produced by the CCSM community, contains new model physics, supports new model resolutions, and has new run scripts. Numerous multi-century control runs were conducted with CCSM3.0 at low, medium, and high resolutions and are available to the general public for examination and analysis. For more information about CCSM3.0 visit CCSM3.0 Public Release Home Page.

What are the CCSM components?
CCSM software is based on framework that divides the complete climate system into component models connected by a coupler. Individual components - ocean, atmosphere, land, and sea-ice - can be exchanged for alternate models, thus allowing different configurations appropriate for different applications.

What is the spatial resolution of the climate change projections produced by the CCSM-3?
The spatial resolution of CCSM-3 climate change projections is approximately 1.4 x 1.4 degrees. However, the model outputs are generated on an irregular grid. The longitude range can be exactly specified - the center of the first grid box is at 0E and the spacing is precisely 1.40625§. The latitudes, however, vary in spacing from 1.389§ to 1.400767§.

What data one can download from this website?
This website provides climate change projections that have been generated for the 4th Assessment Report (AR4) of the IPCC by the Community Climate System Model (CCSM-3). Currently this portal distributes a subset of all variables produced by the CCSM-3, including monthly mean 2D variables from atmosphere and land component models . In addition, one can download downscaled CCSM-3 projections of temperature and precipitation for the contiguous USA

What is downscaling?
Downscaling is the general name for a procedure to take information known at large scales to make predictions at local scales. Statistical downscaling is a two-step process consisting of i) the development of statistical relationships between local climate variables (e.g., surface air temperature and precipitation) and large-scale predictors (e.g., pressure fields), and ii) the application of such relationships to the output of Global Climate Model experiments to simulate local climate characteristics in the future. More information about the method used to downscale CCSM-3 projections is available in this white paper

What is the spatial resolution of downscaled CCSM-3 temperature and precipitation projections?
Spatial resolution of downscaled CCSM-3 projections of temperature and precipitation for the contiguous USA is approximately 4.5 km.

Where can I get climate change projections produced by other global climate models?
The IPCC Data Distribution Centre and Program for Climate Model Diagnosis and Intercomparison (PCMDI) provide IPCC multi-model data and documentation. All IPCC CCSM-3 experiments are also available in NetCDF format through the Earth System Grid data portal.

Where can I learn more about climate change impacts research?
Much of information about climate change impacts can be found in IPCC Working Group II Report on Impacts, Adaptation and Vulnerability.