PNNL

Abstract

Climate change is again in the news. The failure of the recent sixth meeting of the Conference of the Parties to the Framework Convention on Climate Change (FCCC) to agree on terms for the Kyoto Protocol the future of climate policy remains uncertain. It is important to be clear on where efforts need to be focused (in addition to how much effort is required, which would require a separate discussion). The recent paper by Hansen et al. has created some debate and controversy along these lines. In this paper, the authors argue that recent climate changes have been caused largely by non-CO2 greenhouse gases and that climate change over the next fifty years can be limited by focusing not only on carbon dioxide but on non-CO2 greenhouse gases and aerosols. This paper will present an overview of these issues. A few of these points were also discussed in a recent commentary in Science magazine and are not repeated at length here. The discussion below will first address attribution of past climate changes, the radiatively important substances that will drive future climate change, and the mitigation of climate change.Journal name is WRONG. Interface does not allow me to type in correct name. Correct name should be "Physics and Society".