The Framework Convention on Climate Change, opened for signature at the 1992 United Nations Conference on the Environment and Development (UNCED), formally begins a process for countries jointly to limit the long‐term risk of climate change. The near‐term effectiveness of the Framework Convention will be limited, due to ambiguities in language, uncertainties regarding the magnitude and location of sources and sinks, the difference between biological and industrial emissions, uncertainty about the relative importance of the various greenhouse gases and selection of a weighting system, and concerns about equity. Action in the near term will likely cover either CO2alone or just those gases resulting from the use of fossil fuels in the industrialized world. Based on this limitation, it is projected that by 2036 the earth will be committed to a 2.2oC temperature increase. The effectiveness of the Convention need not be as limited as this analysis suggests; it is an evolving document, tailored to be flexible and to respond to the most recent scientific knowle