The Community Climate System Model (CCSM) is producing more than 100 terabytes of data for the upcoming fourth climate assessment of the Intergovernmental Panel on Climate Change. A large percentage of these data are model runs using different climate change scenarios—plausible alternative futures that would result in widely differing greenhouse gas and aerosol emissions over the next hundred years. Now, the UCAR Geographic Information System (GIS) Initiative is offering free access to these CCSM climate change scenario runs in a common GIS format.
"GIS is a tool for easily integrating data sets," explains Olga Wilhelmi of NCAR's Institute for the Study of Society and Environment, the leader of the NCAR GIS Initiative. Users of this technology are not so much the traditional atmospheric science community as social scientists, educators, and public sector professionals. Users in fields such as agriculture, disaster management, and natural resource allocation need information on climate change to assess vulnerability and devise adaptation strategies. GIS is also widely used in secondary and college classrooms. The Web site "is a way to help users put together climate predictions and information on different environmental and social factors," Wilhelmi says.
The GIS climate change Web site allows viewers to choose from among three IPCC scenarios and two control runs, one current and one pre–Industrial Revolution. Users can choose any monthly mean two-dimensional atmospheric or land variable and can view their results as a map, a GIS shapefile, or a text file. The site offers links to a wide range of information for nontraditional users, explaining everything from the purpose of the IPCC reports to the units for each variable and how they are computed.
For each scenario, the storyline and characteristics (e.g., high gross domestic product, rapid technological change) are described in a pop-up window.
"There's a large audience for this data," Wilhelmi points out. Since the Web site came on line in February, it has had more than 11,000 hits. There are currently more than 650 registered users from 70 countries on 6 continents; these users have downloaded a total of almost 2400 files. The data have been used for such diverse purposes as planning airline routes; analyzing risks to a grain storage terminal at the Port of Veracruz, Mexico; examining effects of climate change on health; and producing a Brazilian children's book.