Climate change: the political situation.

The uncertainties of climate predictions are estimated to be ϳ50%, excluding instabilities of the climate system that could yield substantially larger changes, for example, through the collapse of the Gulf Stream and deep ocean circulation system, a break-off of the West Antarctic ice sheet, or the release of methane presently frozen in permafrost regions. 23. Examples are tradable renewable energy permits (27) and long-term policies in tradable emission permits (28, 29). 30. The views expressed in this article evolved from discussions with members and guests of the European Climate Forum (ECF). We acknowledge constructive comments from Peck. However, ECF does not endorse specific views expressed by its members, and this article does not represent an ECF consensus view. Human-induced climate change is one of the most important environmental issues facing society worldwide. The overwhelming majority of scientific experts and governments acknowledge that there is strong scientific evidence demonstrating that human activities are changing the Earth's climate and that further human-induced climate change is inevitable. Changes in the Earth's climate are projected to adversely affect socioeconomic systems (such as water, agriculture, forestry, and fisheries), terrestrial and aquatic ecological systems, and human health. Developing countries are projected to be most adversely affected, and poor people within them are the most vulnerable. The magnitude and timing of changes in the Earth's climate will depend on the future demand for energy, the way it is produced and used, and changes in land use, which in turn affect emissions of greenhouse gases and aerosol precursors. The most comprehensive and ambitious attempt to negotiate binding limits on greenhouse gas emissions is contained in the 1997 Kyoto Protocol, an agreement forged in a meeting of more than 160 nations, in which most developed countries agreed to reduce their emissions by 5 to 10% relative to the levels emitted in 1990. Although the near-term challenge for most industrialized countries is to achieve their Kyoto targets, the long-term challenge is to meet the objectives of Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC), i.e., stabilization of greenhouse gas concentrations in the atmosphere at levels that would prevent dangerous anthro-pogenic interference with the climate system, with specific attention being paid to food security , ecological systems, and sustainable economic development. To stabilize the atmospheric concentration of carbon dioxide requires that emissions eventually be reduced to only a small fraction of current emissions, i.e., 5 to 10% …