America's climate choice: Put up or shut up

Bob Ward is policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science

A leading article in the 16 May edition of the Washington Post issues a blunt challenge to candidates lining up for the presidential elections in 2012: on climate change, it is time to put up or shut up.

The basis of the newspaper's frank article is a powerful new report published last week by the country's National Academy of Sciences which concluded that climate change is already happening and the United States should rapidly reduce its greenhouse gas emissions by introducing a nationwide carbon price.

The report on "America's Climate Choices" was prepared by a panel of leading researchers in response to a request from Congress. It presents a serious challenge to many members of the Senate and House of Representatives, particularly Republicans, who have expressed scepticism and denial about the potential risks posed by climate change.

The Post's article calls for:

every candidate for political office in the next cycle, including for president, should be asked whether they disagree with the scientific consensus of America's premier scientific advisory group, as reflected in this report; and if so, on what basis they disagree; and if not, what they propose to do about the rising seas, spreading deserts and intensifying storms that, absent a change in policy, loom on America's horizon

Chaired by Albert Carnesale of the University of California, Los Angeles, the Academy's panel concluded that "climate change is occurring, is very likely caused by human activities, and poses significant risks for a broad range of human and natural systems".

They acknowledged that:

given the inherent complexities of the climate system, and the many social, economic, technological, and other factors that affect the climate system, we can expect always to be learning more and to be facing uncertainties regarding future risks

But they warned that "this is not, however, a reason for inaction".

The panel pointed out that "the risks associated with doing business as usual are a much greater concern than the risks associated with engaging in strong response efforts". They recommended that "the nation should reduce greenhouse gas emissions substantially over the coming decades", and called for "a comprehensive, nationally uniform, increasing price on CO₂ emissions, with a price trajectory sufficient to drive major investments in energy efficiency and low-carbon technologies".

This is the latest in a series of reports on climate change that have been published by the National Academy of Sciences over the past two years, presenting a clear and compelling assessment of the causes and likely consequences of climate change.

The latest report is all the more remarkable because it was requested by Congress, some members of which have launched personal attacks on prominent climate researchers. Last year 255 members of the National Academy wrote to the journal Science to complain about "the recent escalation of political assaults on scientists in general and on climate scientists in particular".

It also presents a contrast with the most recent report by UK's national academy, the Royal Society, which yielded to demands from self-proclaimed "sceptics" that it should stop calling for policies to combat climate change.

The Society published a guide to "Climate change controversies" in March 2007 which concluded that:

the science clearly points to the need for nations to take urgent steps to cut greenhouse gas emissions into the atmosphere, as much and as fast as possible, to reduce the more severe aspects of climate change

However, complaints last year by 43 of its 1489 Fellows, including members of Nigel Lawson's Global Warming Policy Foundation, about the guide led the Society to revise its assessment. It concluded that

there is strong evidence that changes in greenhouse gas concentrations due to human activity are the dominant cause of the global warming over the last half century

But it conspicuously did not call for a reduction in emissions.

The watered down document constituted a major victory for "sceptics" who have undertaken a campaign to sideline scientists in the public debate about climate change by accusing them of advocacy if they call for any mitigating action that might affect the use of fossil fuels.

Given that all sensible policy responses to climate change involve some level of emissions reductions, as opposed to the extreme approach of simply adapting to the impacts of unabated rises in greenhouse gases, the muting of the voices of the scientific community has distorted the public debate that sceptics are so desperate to win.

Hopefully, the courage shown by the National Academy of Sciences will serve as an example that will stiffen the resolve of their counterparts in the UK.