With regard to strategies
for addressing climate change, the TAR provides an assessment of the potential
for achieving different levels of concentrations through mitigation and
information about how adaptation can reduce vulnerability. The causality
works in both directions. Different stabilization levels result from different
emission scenarios, which are connected to underlying development paths.
In turn, these development paths strongly affect adaptive capacity in
any region. In this way adaptation and mitigation strategies are dynamically
connected with changes in the climate system and the prospects for ecosystem
adaptation, food production, and sustainable economic development.
|WGII TAR Chapter 18 & WGIII TAR Chapter 2|
An integrated view of climate change considers the dynamics of the
complete cycle of interlinked causes and effects across all sectors
concerned. Figure 1-1 shows the cycle,
from the underlying driving forces of population, economy, technology,
and governance, through greenhouse gas and other emissions, changes
in the physical climate system, biophysical and human impacts, to adaptation
and mitigation, and back to the driving forces. The figure presents
a schematic view of an ideal "integrated assessment" framework,
in which all the parts of the climate change problem interact mutually.
Changes in one part of the cycle influence other components in a dynamic
manner, through multiple paths. The TAR assesses new policy-relevant
information and evidence with regard to all quadrants of Figure
1-1. In particular, a new contribution has been to fill in the bottom
righthand quadrant of the figure by exploring alternative development
paths and their relationship to greenhouse gas emissions, and by undertaking
preliminary work on the linkage between adaptation, mitigation, and
development paths. However, the TAR does not achieve a fully integrated
assessment of climate change, because of the incomplete state of knowledge.
|WGII TAR Chapters 1 & 19, WGIII TAR Chapter 1, & SRES|
Climate change decision
making is essentially a sequential process under general uncertainties.
Decision making has to deal with uncertainties including the risk of non-linear
and/or irreversible changes and entails balancing the risk of eitherinsufficient
or excessive action, and involves careful consideration of the consequences
(both environmental and economic), their likelihood, and society's
attitude towards risk. The latter is likely to vary from country to country
and from generation to generation. The relevant question is "what
is the best course for the near term given the expected long-term climate
change and accompanying uncertainties."
|WGI TAR, WGII TAR, & WGIII TAR Section 10.1.4|
Climate change impacts
are part of the larger question of how complex social, economic, and environmental
subsystems interact and shape prospects for sustainable development.
There are multiple links. Economic development affectsecosystem balance
and, in turn, is affected by the state of the ecosystem; poverty can be
both a result and a cause of environmental degradation; material- and
energy-intensive life styles and continued high levels of consumption
supported by non-renewable resources and rapid population growth are not
likely to be consistent with sustainable developmentpaths; and extreme
socio-economic inequality within communities and between nations may undermine
the social cohesion that would promote sustainability and make policy
responses more effective. At the same time, socio-economic and technology
policy decisions made for non-climate-related reasons have significant
implications for climate policy andclimate change impacts, as well as
for other environmental issues (see Question 8).
In addition, critical impact thresholds and vulnerability to climate change
impacts are directly connected to environmental, social, and economic
conditions and institutional capacity.
As a result, the effectiveness of climate policies
can be enhanced when they are integrated with broader strategies designed
to make national and regional development paths more sustainable.
This occurs because of the impacts of natural climate variation and changes,
climate policy responses, and associated socio-economic development will
affect the ability of countries to achieve sustainable development goals,
while the pursuit of those goals will in turn affect the opportunities
for, and success of, climate policies. In particular, the socio-economic
and technological characteristics of different development paths will
strongly affect emissions, the rate and magnitude of climate change, climate
change impacts, the capability to adapt, and the capacity to mitigate
climate. The Special Report on Emissions Scenarios (SRES, see
Box 3-1) outlined multiple plausible
future worlds with different characteristics, each having very different
implications for the future climate and for climate policy.
|WGIII TAR Section 10.3.2|
|1.11||The TAR assesses available
information on the timing, opportunities, costs, benefits, and impacts of
various mitigation and adaptation options. It indicates that there
are opportunities for countries acting individually, or in cooperation with
others, to reduce costs of mitigation and adaptation and realize benefits
associated with achieving sustainable development.
||WGII TAR Chapter 18, WGIII TAR Chapters 8, 9, & 10, & SRES|
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