Munich Economic Summit
Thursday, 28 May 2009
Ottmar Edenhofer
Deputy Director, Potsdam Institute for Climate Impact Research
Adapt, mitigate, or die? The fallacy of a false trade-off
Managing the problem of climate change will require the weighing
of different kinds of risks arising from climate change, adaptation, and mitigation.
The Climate Challenge
Climate change poses a permanent and serious threat to human development and
prosperity. With rising temperatures, climate change is likely to become unmanageable
and catastrophic, pushing the Earth's complex ecology past known and as yet
unknown tipping points, which may fundamentally and irreversibly alter the
way our planet functions. Key impacts of climate change include flooding of
coastal areas and river deltas, more intense droughts and desertification,
increased occurrence of weather extreme events, and water scarcity due to
melting glaciers and changing precipitation patterns. Developing countries
are particularly vulnerable to climate change.
2 Degrees - 2 Tasks
In light of these dangers, the European Union has formulated the objective
to limit global warming to 2°C above pre-industrial levels. Climate modelling
results suggest that the EU's 2°C-target will be sufficient to avoid triggering
intermediately sensitive tipping elements. At the same time, the 2°C target
defines the burden sharing between mitigation and adaptation. Concerning the
cost of mitigating climate change, an economic consensus has emerged that
they will be relatively low at the order of magnitude of 1-2% of global GDP.
However, this requires that action is taken quickly and effective institutions
and technologies are put into place on a global scale. Given that the costs
of limiting the rise of global mean temperature to 2°C are relatively
moderate, and that major impacts of climate change regarding tipping elements
and ecosystem changes may be avoided when limiting global warming to 2°C,
this appears to be a reasonable target for international climate policy in
a Global Contract on Climate Change.
A Global Contract
Holding the 2°C threshold will require an institutional framework that
can deliver on the criteria of environmental effectiveness (reducing emissions
in accordance with the 2°C limit), economic efficiency (doing so at least
costs), and equity (taking into account different responsibilities and capabilities
in mitigating and responding to climate change). Along these lines, we propose
that a Global Contract should focus on four major issues: establishing a global
carbon market, fostering the development and sharing of low carbon technologies,
reducing emissions form deforestation and land degradation (REDD), and adapting
to the impacts of a +2°C world. After all, we do not have the luxury to
choose between adaptation and mitigation; we have to do both - or die.
