Potsdam, 12.12.03
The Kyoto protocol and short-term
reduction targets for greenhouse gas emissions are an important first
step in tackling climate change. However, these need to go hand in hand
with long-term commitments. Model-based estimates up to the year 3000
show that a gradual transition to an emission-free economy is possible
at an acceptable price within the next 50 to 100 years. The findings
were published by several members of the European Climate Forum (ECF)
in the current issue of Science magazine (12.12.03).
To
avoid dangerous climate change, global per capita greenhouse gas
emissions need to be reduced to a small fraction of the present levels
of developed countries within the next hundred years. In the worst
case, if all available fossil fuel resources (conventional and exotic)
are used and emissions are not reduced, model simulations indicate that
the sea level could rise by about eight meters and the average air
surface temperature by about nine degrees Celsius in the later part of
this millennium.
Because of the long residence time of CO2 of
more than 100 years in the atmosphere, climate response is governed by
cumulative rather than current CO2 emissions. Important is not the
detailed emissions path, but that emissions are strongly reduced over a
period of 50 to 100 years. Thus the detailed reductions achieved during
the Kyoto period are less critical than the start of a transition to a
sustainable path of continually decreasing emissions. This requires
policies extending well beyond the Kyoto horizon. Cost estimates
indicate that the implementation of an effective climate policy would
delay economic growth over a period of fifty years by perhaps one to
two years - an acceptable price for the avoidance of dangerous climate
change.
Since energy technologies are characterized by long
capital lifetimes, clearly stated long-term policy goals and supporting
measures are needed to influence the necessary business investments.
This is important also for the public, which must understand and
support the policies. For the expanding populations of the developing
world, which strive to achieve the same living standards as the
industrial countries, long-term policies are equally essential. A
fossil-fuel-based development path for these countries would greatly
increase global emissions. A number of low-emission technological
options exist. Although some are already now cost-effective (for
example wind), major emission reductions will require additional
technologies (such as solar), which are currently more expensive. These
will be developed and the costs reduced only if timely supporting
policies are introduced. Alternative low-carbon development paths are
in sight both for the industrial and developing world, but candidate
technologies need the support of a long-term climate policy now.
Binding
commitments to meet short-term emissions-reductions targets must
therefore go hand in hand with clearly defined strategies to achieve
significantly more stringent reductions in the longer term. A stronger
focus on the long-term development of sustainable energy technologies
could assist also in overcoming the present impasse of the Kyoto
process and in reducing north-south inequity issues.
European
Climate Forum (ECF) provides a platform for joint studies, dialogues
and the exchange of views between scientists, corporations, companies
and NGOs. The non-profit association was founded in 2001 by seven
leading European research institutes in the field of climate and energy
studies as well as business and NGO members. The referred paper does
not represent an ECF consensus view. See: www.european-climate-forum.net
Original article:
K.
Hasselmann, M. Latif, G. Hooss, C. Azar, O. Edenhofer, C. C. Jaeger, O.
M. Johannessen, C. Kemfert, M. Welp and A. Wokaun. 2003. The Challenge
of Long-term Climate Change. Science magazine. Vol. 302, Number 5652,
12 December 2003. (www.sciencemag.org)
Contact:
Prof. Klaus Hasselmann, klaus.hasselmann@dkrz.de, Tel. +49-40-411 73 236
Graphic material can be viewed on the internet:
www.pik-potsdam.de/news-1/press-releases/archive/2003/emissionen (German version only)
