A Climate for Change

(^256) Human Development Report - Croatia 2008
Overview of IPCC Climate Change Emissions
Scenarios (IPCC 2007a)
In addition to various climatic data and other variables,
climate models require some type of prediction of
how global society will develop in terms of energy use
(the type of energy used and the quantity), popula-
tion growth and economic growth. All of these are im-
portant for predicting GHGs, which directly influence
climate change. The different projections are usually
called emissions scenarios. The most well-known (and
the most common) emissions scenarios are those de-
veloped by the Intergovernmental Panel on Climate
Change (IPPC). However, other scenarios developed
by other projects also exist, such as scenarios from the
EU-funded project ADAM.III When models are run with
the same climate data for various emissions scenarios,
they produce various climate change projections. It is
also possible to run different models with the same
emissions scenario, which will yield somewhat differ-
ent results for the future climate.
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Global GHG emissions (Gt CO
-et/yr.) 2
Year
post-SRES (max)
post-SRES (min)
2000 2020 2040 2060 2080 2100
B1
post-SRES range (80%)
A1T
B2
A1B
A2
A1FI
Figure 1: Global GHG emissions (in Gt CO 2 -eq per year):
six illustrative SRES (Special Report on Emissions Scenarios)
scenarios (coloured lines) and 80th percentile range of recent
scenarios published since SRES (post SRES) (grey area). Dashed
lines show the full range of post SRES scenarios. The emissions
include CO 2 , CH 4 , N 2 O and F-gases
Source: IPCC 2007a.
Figure 1 shows the range of error of GHGs emissions
expressed in Giga tonnes (Gt) of CO 2 equivalent per
year. Coloured lines represent different IPCCs SRES
emission scenarios, and the grey area represents the
80 th percentile of published research since SRES sce-
narios have been presented (post SRES), while the
dashed line shows the full range of published stud-
ies.^3 Up to now, the IPCC SRES emission scenarios
have been those most utilised by various projects and
study groups.
A1: Rapid convergent growth: The A1 scenario de-
scribes a future world of very rapid economic growth
and global population that peaks mid-century and
declines afterwards, along with the rapid introduction
of new and more efficient technologies. The major
underlying themes are convergence among regions,
capacity building, and increased cultural and social in-
teractions, with a substantial reduction in regional dif-
ferences in per capita income. The difference between
the A1FI, A1B, A1T scenarios are mainly in the source
of energy used to drive this expanding economy.
A1FI: Fossil-fuel Intensive, fossil fuels continue to dom-
inate the energy supply for the foreseeable future.
A1B: Balance between fossil fuels and other energy
sources
A1T: Emphasis on new Technology using renewable
energy rather than fossil fuel.
A2: Fragmented world: The A2 emissions scenario
describes a very heterogeneous world. The underly-
ing theme is self-reliance and preservation of local
identities. Fertility patterns across regions converge
very slowly, which results in a continuously increas-
ing global population. Economic development is pri-
marily regionally oriented and per capita economic
growth and technological change is more fragmented
and slower than in other storylines.
Basic Information about Climate Models
I ADAM (Adaptation and Mitigation Strategies: supporting Eu-
ropean climate policy) is an integrated research project running
from 2006 to 2009 that will lead to a better understanding of the
trade-offs and conflicts that exist between adaptation and miti-
gation policies. ADAM will support EU policy development in the
next stage of development of the Kyoto Protocol and will inform
the emergence of new adaptation strategies for Europe.
More information: http://www.adamproject.eu/.