Climate Economics Seminar: The RCP Scenarios for the IPCC AR4 (and beyond): 250 years of pollutant and GHG emissions
Date(s): September 16, 2009, 10;30 am to noon
Location: Room 5126, EPA West, 1301 Constitution Avenue, NW, Washington, DC
Presenter: Steven J. Smith (Joint Global Change Research Institute; Pacific Northwest National Laboratory and the University of Maryland)
Description: Consistent long-term scenarios for emissions of greenhouse gases and air pollutants, land-use, socio-econmic variables, and energy consumption are needed for coordinated analysis of future climate change, impacts, mitigation, and adaptation. To meet this need, the integrated assessment, earth-system modeling, and emission inventory development communities have organized to implement a new process for scenario development and application. This is a departure from past practice, whereby the Intergovermental Panel on Climate Change (IPCC) has organized scenario construction exercises, the most recent being the Special Report on Emissions Scenarios (SRES). The initial phase of this new community-lead process is nearing completion: the release of a set of Representative Concentration Pathways (RCPs) to be used for model inter-comparison experiments leading to the IPCC AR5. The RCP scenarios are intended to represent the full range of potential future radiative forcing pathways ranging from a no-climate policy high forcing scenario (8.5 W/m^2 total anthropogenic forcing in 2100) to a "peak and decline" scenario (with 2.6 W/m^2 forcing in 2100). The RCP scenarios were developed using integrated assessment models that combine economics, technology, and physical processes. The scenarios include a full suite of greenhouse gas concentrations, spatially explicit emissions for pollutant gases and aerosols, and spatially explicit land-use and land-use change information. The RCP scenarios, the development process, and the next phases of scenario research will be discussed.