CLIMATE CHANGE Response to Simmonds and Steffen

for their interest in our paper. In response, and at the outset, we confirm that the paper under discussion1 represents the combined and considered professional views of its authors. Beyond that, we do not wish to respond to suggestions that we have not studied the literature thoroughly, not understood some of the concepts under discussion, or not given consideration to the wide range of legitimate views that can defensibly be held on the global warming issue—towards one end of which lies the Intergovernmental Panel on Climate Change (IPCC) orthodoxy that Simmonds and Steffen so spiritedly espouse. Here, in the interests of brevity, we restrict our remarks to those points amongst the matters that they raised that we view as particularly important or informative.