G3S: Balancing RCP4.5 forcing via a reduction of solar constant
Model: MPI-ESM-CMIP5 T64L47 GR15
The experiments use CMIP experiment RCP4.5 as base experiment, where the
anthropogenic forcing rises up to 4.5 W/m2 in the year 2100. Using
climate engineering approaches, the radiative forcing of
anthropogenic GHGs and aerosols should be
balanced to maintain the net radiative forcing at the top of the
atmosphere (TOA) of the year 2020. The principle of this experiment is
described in (Kravitz et al, ASL, 2011). The amount of anthropogenic forcing
for each year is given in the CMIP 5 protocol. Forcing data are taken from
http://www.pik-potsdam.de/$\sim$mmalte/rcps/index.htm.
We studied the impact of different SRM methods on climate and
performed several simulations under the same forcing conditions but
using different climate engineering techniques to balance the
anthropogenic radiative forcing: injection of sulfate aerosols into the
stratosphere (G3), reducing the solar constant (G3S) and emission of
sea salt aerosol over the ocean to brighten strato cumulus clouds
(G5). To control the balancing process, an additional control
experiment has been performed: the anthropogenic forcing is kept frozen on
2020 level (G3C). This simulation can also be seen as massive mitigation
strategy, e.g. using carbon capture.