FE433 Climate change in the 21st Century: interim characterizations based on the new IPCC emissions scenarios

Timothy R.Carter, Mike Hulme, Jennifer F. Crossley, Sergey Malyshev, Mark G.New, Michael E.Schlesinger, Heikki Tuomenvirta, 2000

Finnish Environment 433, international cooperation, p. 148
URN:ISBN:9521107812. The publication is available only in printed form ISBN 952-11-0781-2.

Abstract:

Emissions of greenhouse gases and aerosols into the atmosphere are believed to be changing the Earth's climate. In order to study the possible impacts of such changes on natural and human systems, plausible scenarios of future climate are required that represent the range of uncertainty in projections. These scenarios should also be consistent with other scenarios of concurrent socio-economic and environmental changes.

The Intergovernmental Panel on Climate Change (IPCC) has recently developed a new set of emissions scenarios for the Special Report on Emissions Scenarios (SRES). The scenarios span a wide range of uncertainties in future emissions arising from different assumptions of socio-economic development during the 21st century. Their effects on climate are currently being estimated using coupled atmosphere-ocean general circulation models (AOGCMs), but a representative set of AOGCM results spanning the SRES range of emissions is not yet available for use in impact assessment.

In the interim, this report presents an alternative method of characterizing the implications of the SRES emissions scenarios for regional climate. The method combines estimates of the global mean climate response to the SRES scenarios, using a simple climate model, with estimates of the regional pattern of climate response from AOGCM simulations assuming earlier emissions scenarios. Projected changes in mean seasonal temperature and precipitation are portrayed for the 2020s, 2050s and 2080s relative to 1961-1990 on global maps and on graphs for thirty-two world regions. Uncertainties in both the magnitude and direction of future regional climate change are depicted, based on a range of SRES scenarios and patterns from ten AOGCM simulations.

In addition, information is presented on the demographic and socio-economic driving factors underlying the SRES scenarios, the atmospheric carbon dioxide concentrations implied by the scenarios, and model estimates of global sea-level rise induced by projected temperature changes. All of these factors may also be important for determining future vulnerability to a changing climate.