Geoscience Reference
In-Depth Information
beyond has been created. A limited number of SRES scenarios have
been selected to explore some contrasting trajectories:
- scenario SRESB1, the most optimistic, predicts a rapid evolution
toward a service and information economy, leading to global solutions
to ensure the eco-responsible evolution of societies;
- scenario SRESA2 describes a heterogeneous world, privileging
regional economic growth;
- scenario SRESA1F1 describes a world of rapid economic growth
relying on technological evolutions that permit the intensive
exploitation of fossil fuels.
Economic
+
A1
A2
Global
+
Regional
+
B1
B2
Envrionmental
+
Figure 2.3.
Schematic representation of weights of
hypotheses used in SRES scenarios
This strategy has been deeply modified following the IPCC AR4
report, to permit research groups working on climate physics and
those working on socio-economic modeling to work in parallel. The
idea is now to work with the imposed trajectories of concentration,
called RCP for the
Representative Concentration Pathway
, which have
been proposed by Moss
et al.
[MOS 08] and which now serve as
conditions of external forcing for climate models as well as for socio-
economists who need to construct the conditions of societal evolution
which will allow these trajectories to be reached.
The construction of RCP scenarios is largely inspired by the SRES
scenarios used previously. Their name is determined by the value of
total radiative forcing from GHG emissions reached in 2100
