1 CHOOSING A STABILIZATION TARGET FOR CO2

[To be published as an editorial essay in Climatic Change] Article 2 of the UN Framework Convention on Climate Change (UNFCCC) provides a key and much-quoted statement that is meant to guide us in our efforts to stabilize the effects of mankind on the climate system. The ultimate objective of this Convention is to achieve “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system ….. within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner”. This is a strong yet frustratingly vague statement, and scientists and policy makers have been agonizing over the meaning of ‘dangerous interference ’ ever since the UNFCCC was published. It raises other important questions. Even if the ‘dangerous interference ’ concept were well defined, what would this mean for choosing a stabilization target for CO2 and the other greenhouse gases that we produce? … and, given such targets, what pathway should we take towards stabilization, given that the pathway may determine whether or not we ca