What can be done to prevent further climate change?

Climate Change 2001: Mitigation

Edited by Bert Metz, Ogunlade Davidson, Rob Swart and Jiahua Pan

Carbon dioxide (CO₂) emissions can be reduced by concerted international effort, and even by regional and local initiatives. That is the message of Volume III of Climate Change 2001: Mitigation. The effort will be enormously complex, however, and fraught with political and economic difficulties.

The IPCC’s report presents six different scenarios of future development and their effect on CO₂ emissions over the coming century. The scenarios which lead to reduced CO₂ emissions tend to require policy shifts towards sustainable development and greater equity within and between nations.

The good news is that technological progress to reduce emissions or find new, non-fossil energy sources has been faster than anticipated in the second IPCC assessment report (1996). More efficient hybrid engine cars, wind turbines and elimination of some industrial by-product gases are examples. Carbon sinks, such as forests or agricultural systems, are also important in offsetting carbon emissions, at least in order to buy time.

For these known technological and biological options to reduce carbon emissions, however, significant socio-economic, developmental and even societal changes may be necessary. Just as the consequences of climate change will tend to hit developing nations harder, so too will the process of mitigation, owing to the same inequitable distribution of resources and technologies.

One of the six scenarios outlined in the report, for example, describes a 21st century world where global population peaks in mid-century, economic growth is very rapid, and where new and more efficient technologies are quickly introduced. Convergence among regions, capacity building and increased cultural and social interactions are envisaged, together with substantial reductions in regional differences in per-capita income. The balance of energy resources in this world shifts predominantly towards non-fossil sources.

Under this scenario, carbon emissions continue to rise steadily during the first part of the century before slowly declining to levels equal to or below those of 1990. A similar scenario where fossil fuels remain the predominant energy source sees carbon emissions climb steadily throughout the 21st century until they are between five and seven times higher than in 1990.

Under all the scenarios, the most positive effects are seen where effort is made to stabilise carbon concentrations in the atmosphere at certain given levels.

In attempting to quantify the costs and ancillary benefits of climate mitigation, Climate Change 2001 acknowledges the difficulties in such an exercise. Differences in ways of measuring benefit, in the scope and methodology of analysis, and in the underlying assumptions built into the analysis all contribute to the difficulty of calculating costs.

It is possible to say, however, that certain emissions controls can be achieved without net social cost, and that climate control policies can have other ancillary benefits such as reductions in pollution. Where action is coordinated between countries there may also be reductions in mitigation costs, and the effectiveness of mitigation can be enhanced by broad transition strategies to achieve long term social and technological change.

Because of the high element of uncertainty and risk involved in planning mitigation, Climate Change 2001 concludes with a summary of gaps in knowledge which need to be filled. The report recommends further research in: the potential of technological and social innovations; economic, social and institutional issues; better ways of analysing mitigation options and their costs; and evaluating climate mitigation in the context of development, sustainability and equity.

Note to Editors

All figures and scenarios quoted above are taken from the Summary for Policy Makers chapter in Volume III of Climate Change 2001.

 

Climate Change 2001: Mitigation Binding: Hardback (Paperback) | ISSN: 0 521 80769 7 (hb) 0 521 01502 2 (pb) | Publication: 12th July 2001

Further information

For further information on Climate Change 2001 and to secure your review copies, please contact Hannah Proctor, Marketing Controller, Cambridge University Press by email to hproctor@cambridge.org or telephone +44 (0)1223 325782