IPCC Arctic GCM scenarios
Please contact William Chapman with questions and/or comments.
Emission scenarios developed by the Intergovernmental Panel on Climate
Change (IPCC)
contain a set of climate forcing
factors that can be used for coupled ocean-atmosphere simulations
of 20th, 21st and 22nd century climate. The forcing is given in
terms of solar irradiance, volcanic aerosol optical depth,
anthropogenic aerosols, and atmospheric concentrations of ozone,
carbon dioxide, and other well mixed greenhouse gases.
The Intergovernmental Panel on Climate Change recommends
modeling groups contributing to the IPCC Fourth Assessment Report
(4AR) include the following scenarios of climate forcing:
- a "committed climate change" scenario with realistic
20th century forcing, followed by constant atmospheric
concentrations from year 2000 to at least 2050
- a "750 ppm stabilization" scenario with realistic 20th
century forcing, followed by atmospheric concentrations
based on the IPCC's Special Report on Emissions Scenarios
(SRES) scenario A1B for years 2000 - 2100, then extended
with constant concentrations to at least 2200
- a "550 ppm stabilization" scenario with realistic 20th
century forcing, followed by atmospheric concentrations
based on SRES scenario B1 for years 2000 - 2100, then
extended with constant concentrations to at least 2200
- a scenario with realistic 20th century forcing, followed
by atmospheric concentrations based on SRES scenario A2
for years 2000 - 2100
- idealized scenarios in which atmospheric carbon dioxide
(1) increases at the rate of 1% per year, and (2) is doubled
or quadrupled and then held fixed until an equilibrium climate
state is reached
Documentation for this
particular set of climate forcing factors may be found in Ammann, C.M.,
G.A. Meehl, W.M. Washington, and C. Zender, 2003: A monthly and
latitudinally varying volcanic forcing dataset in simulations of 20th
century climate. Geophys. Res. Lett., 30, doi:10.1029/2003GL016875RR,
and Dai, A., T.M.L. Wigley, B.A. Boville, J.T. Kiehl, and L.E. Buja,
2001: Climates of the twentieth and twenty-first centuries simulated by
the NCAR Climate System Model. J. Climate, 14, 485-519.
