There has been some modest progress over the past 12 months in the international negotiations over climate change, but there is still an insufficient understanding of the urgency with which the science indicates we should be dealing with this challenge. We have seen the intense build-up to the 15th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC), COP15, in Copenhagen in December 2009 and the deep disappointment in the outcome; the mid-term elections in the United States of November 2010, which have essentially removed the possibility of strong federal climate legislation for the foreseeable future; and the publication in October 2010 of the outline of China's 12th five-year plan (for the period 2011-15), which appears to set a clear route towards low-carbon growth. Now that COP16, the UNFCCC conference following Copenhagen, has taken place in Cancun, Mexico--constructive both in atmosphere and outcome--where do we stand on prospects for international and national action on climate change?
These last two years have also seen a fallback among some developed countries in the national and international priority given to climate change for two primary reasons: first, the assault on climate science, and second, the international financial and economic crisis. The effects of both are temporary, but there is no doubt that they have contributed significantly to the shift of climate change down the agenda in many parts of the rich world. Many emerging-market economies and poorer countries have, however, been deepening their analyses and commitments.
Assault on Climate Science
The attack on climate science has in many ways been scurrilous and dishonest. It has worked in large part in three ways: by deliberately confusing the uncertainty over the potential magnitude of climate change with uncertainty over the presence of the phenomenon; by grossly magnifying the significance of a few errors in a report of the Intergovernmental Panel on Climate Change (IPCC); and by occasional innuendo and character assassination. First, climate change is all about risk. We cannot predict exactly the climate consequences of any particular emissions path. But science has shown that the greenhouse effect is real and that the risks are potentially very large. In doing so, it builds upon sound theory and compelling evidence, beginning with the work of the great French physicist and mathematician Joseph Fourier in the 1820s. The basic physics and chemistry of how greenhouse gases prevent the escape of energy from the atmosphere are robust and well-founded, and the evidence has become ever stronger. The science has been set out clearly and convincingly by the national scientific academies of countries around the world, from the United States to China to Australia. The advocacy of policy based on the assumption that the best guess at the magnitude of the effect is small or zero--when science points overwhelmingly to potentially large, if uncertain, effects--is unscientific, irrational, and dangerous. It is unscientific because it ignores or rejects sound science, and irrational and dangerous in its treatment of risk because there are potentially dire consequences from increasing concentrations of greenhouse gases if the science is right, and great difficulties in reversing or dealing with rising concentrations if we choose to act on the assumption that the science is wrong.
Second, there have no doubt been some errors in a few of the many thousands of papers and reports used by the IPCC to assess the origins and consequences of climate change. This will surely be the case in any very large body of scientific evidence. But when errors are found--and we should search constantly for errors, as science advances in this way--we must ask how important they are to the overall weight and balance of the argument. Critics of the IPCC have tried to make much of the mistaken claim that Himalayan glaciers could melt by 2035, which appears once within the 3,000 pages of the IPCC report. …