Transcript SRES scenarios: Or, what can we say about the evolution of the

SRES scenarios: Or, what can we
say about the evolution of the
global energy-economic system?
Anand Patwardhan
IIT-Bombay
Why SRES?
SRES
Local,
regional,
sectoral
drivers
Emissions
Climate
change
Changes in
exposure
Exposure
Baseline (or
“current”)
vulnerability
Future
vulnerability
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SRES in brief
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Builds on, and replaces the IS92 scenarios
Qualitative: storylines
Quantitative: several model-based quantitative
scenarios corresponding to each storyline
Descriptive (neither desirable nor undesirable)
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Although no scenario is really value-free
No best-guess or business-as-usual scenario
(IS92a was often used as a BAU case), no
assignment of probability or likelihood to any
scenarios
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SRES structure
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Each SRES storyline represents different
demographic, social, economic, technological
and environmental developments
While storylines start from the same point, they
diverge, gradually in irreversible ways
Storylines are numbered, to avoid
interpretations that may reflect a value
judgment (ex: “green and clean”)
Each scenario represents a specific quantitative
interpretation of one storyline (note: multiple
interpretations are possible)
These quantitative interpretations are obtained
using a range of energy-economic models
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Scenarios
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Four storylines (A1, A2, B1, B2)
Six scenario groups – one each for A2,
B1, B2, and three for A1 (A1F1 – fossil
fuel intensive, A1B – balanced, A1T –
predominantly non-fossil)
Six modeling teams produced a total of
40 scenarios across these six groups
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A1 storyline
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The A1 storyline and scenario family describes a future
world of very rapid economic growth, low population
growth, and the rapid introduction of new and more
efficient technologies. Major underlying themes are
convergence among regions, capacity building, and
increased cultural and social interactions, with a
substantial reduction in regional differences in per capita
income.
Primary features:
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Strong commitment to market-based solutions.
High savings and commitment to education at the household
level.
High rates of investment and innovation in education,
technology, and institutions at the national and international
levels.
International mobility of people, ideas, and technology
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A2 storyline
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The A2 storyline and scenario family describes a very
heterogeneous world. The underlying theme is selfreliance and preservation of local identities. Fertility
patterns across regions converge very slowly, which results
in high population growth. Economic development is
primarily regionally oriented and per capita economic
growth and technological change are more fragmented and
slower than in other storylines
Primary dynamics:
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The A2 world “consolidates” into a series of economic regions.
Self-reliance in terms of resources and less emphasis on
economic, social, and cultural interactions between regions
are characteristic for this future.
Economic growth is uneven and the income gap between
now-industrialized and developing parts of the world does not
narrow, unlike in the A1 and B1 scenario families
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B1 storyline
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The B1 storyline and scenario family describes a
convergent world with the same low population growth as
in the A1 storyline, but with rapid changes in economic
structures toward a service and information economy, with
reductions in material intensity, and the introduction of
clean and resource-efficient technologies. The emphasis is
on global solutions to economic, social, and environmental
sustainability, including improved equity, but without
additional climate initiatives
Primary dynamics:
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high level of environmental and social consciousness
combined with a globally coherent approach to a more
sustainable development.
Economic development in B1 is balanced, and efforts to
achieve equitable income distribution are effective
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B2 storyline
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The B2 storyline and scenario family describes a world in which
the emphasis is on local solutions to economic, social, and
environmental sustainability. It is a world with moderate
population growth, intermediate levels of economic development,
and less rapid and more diverse technological change than in the
B1 and A1 storylines. While the scenario is also oriented toward
environmental protection and social equity, it focuses on local
and regional levels
Primary dynamics:
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The B2 world is one of increased concern for environmental and
social sustainability compared to the A2 storyline.
Increasingly, government policies and business strategies at the
national and local levels are influenced by environmentally aware
citizens, with a trend toward local self-reliance and stronger
communities.
International institutions decline in importance, with a shift toward
local and regional decision-making structures and institutions.
Human welfare, equality, and environmental protection all have high
priority, and they are addressed through community-based social
solutions in addition to technical solutions, although implementation
rates vary across regions
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Another four-way view at the
global level
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Primary drivers
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Demographic change (population and
population structure)
Social and economic development
Rate and direction of technological
change
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Population
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Economic development
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All scenarios describe futures that are more affluent than
today (10-fold to 26-fold increase in gross world product
by 2100)
The A1 scenario family with a “harmonized” gross world
product of US$529 trillion (all values in 1990 US dollars
unless otherwise indicated) in 2100 delineates the SRES
upper bound, whereas B2 with “harmonized” US$235
trillion in 2100 represents its lower bound. The range of
gross world product across all scenarios is even higher,
from US$197 trillion to 550 trillion by 2100
A narrowing of income differences among world regions is
assumed in many scenarios – two families, A1 and B1
explicitly explore pathways to close income gaps in relative
terms
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Structural change in the energy
system
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Global land-use change
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Energy – income linkage
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SRES scenario quantification
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42.htm
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What do we do with SRES (in the
V&A context)?
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Nothing
Use / adapt the storylines – to what
extent can we make them relevant at
local / regional level?
Use driver values for particular scenarios
at national level to bound / constrain local
drivers
Aggregate / upscale driver values for local
scenarios to check consistency with SRES
scenario group
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Final points
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Primary objective of SRES exercise was to
produce emissions of greenhouse gases as the
output, not changes in exposure units
SRES scenarios are intended to exclude
catastrophic futures
The SRES scenarios are not scenarios of the
evolution of the coupled system:
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They specifically exclude climate change policies
(although they purport to include the effect of nonclimate policies)
Similarly, the scenarios exclude the possible feedback
from the climate system on the biosphere
You can check the scenarios themselves (and
much more) at CIESIN: http://sres.ciesin.org
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