chapter - Atmospheric and Oceanic Science

Climate scenarios
logical future. Within each family one or more scenarios consider the global energy,
the industry and other developments together with their implications in terms of
GHG and other pollutant emissions. Although the storylines do not contain explicit
climate change policy measures, there are some examples of indirect mitigation
actions in some scenarios.
The four marker scenarios called A1, A2, B1 and B2, combine two sets of
divergent trends: one set varying between strong economic values and strong environmental
values and the other set between increasing globalization and increasing
regionalization (Fig. 12.1). The storylines can be described as follows:
A1: Assumes a future world with a rapid economic growth, low population
growth and a rapid introduction of new and more efficient technology. Main characteristics
include an economic and cultural convergence and capacity building,
with a substantial reduction in regional differences in per capita income. In a world
of these characteristics, population looks for a personal well being rather than environmental
quality.
A2: Assumes a well differentiated world in which regional cultural identities
are preserved with emphasis on family values and local traditions, high population
growth and different economic development, although high in the global average.
B1: Assumes a convergent world with rapid changes in economic structures
and introduction of clean technologies. The emphasis is on global solutions to environmental
and social sustainability, including efforts for rapid technology development,
“dematerialization” of the economy and improving social equality.
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Fig. 12.1.
Dimensions involved in
the four scenarios of
SRES emissions
proposed by the IPCC.