Full of hot air - a critique by Sir John Houghton of "An appeal to Reason" by Nigel Lawson

source: http://www.nature.com/climate/2008/0807/full/climate.2008.60.html

For a longer version: http://catscience.blogspot.com/2009/01/full-of-hot-air-critique-by-sir-john.html

Full of hot air

Sir John Houghton

Far from being cool and rational, Nigel Lawson's offering on climate change is largely one of misleading messages.

An Appeal to Reason: A Cool Look at Global Warming

by Nigel Lawson

Duckworth Overlook: April 2008 149 pp. £9.99

Although there remains uncertainty in many aspects of climate science, as in all science, over the past few years an overwhelming and well-founded acceptance has emerged, not only in the scientific community, but among the general public and in political arenas, that human activity, and in particular the burning of fossil fuels, is warming the planet. Far from the debate being over, with this awareness the discourse on climate change has largely moved from one of questioning the science to disputing what ought to be done about the problem.

Into this arena enters An Appeal to Reason by Nigel Lawson, former Chancellor of the UK Exchequer, who makes a call for "a cool look at global warming". Journeying through the science, politics, economics and ethics of climate change, Lawson challenges head-on the aspects of conventional wisdom that he believes to be flawed, and shines a light on what he interprets as spinning of rhetoric by the media and politicians.

Promised as a "rare breath of intellectual rigour" and a "hard headed examination of the realities" of climate change, this offering is neither cool nor rational. Although Lawson makes some worthwhile critiques of energy policy, presenting an argument for carbon taxation over carbon trading, for example, and gives some insights into how a deal on mitigating warming involving both developed and developing nations might work, his book is largely one of misleading messages.

The first of these is his questioning of the reality of human-caused global warming itself. Early in the book, showing a surprising ignorance of elementary statistical analysis, Lawson takes the record of global average temperature in the first seven years of this century as evidence that the scientists must have it wrong. By themselves, these years show no significant increase in temperature, but they are warmer on average by almost 0.1 °C than the previous seven years. Even a casual inspection of the global record from 1970 shows two things: first a clear trend of about a 0.5 °C increase over the past 30 years, and second a substantial year-to-year variability of the kind that is well known to climatologists and has been attributed to phases of the El Niño/La Niña phenomenon, a regular feature of the Pacific climate.

Lawson then challenges the carefully worded conclusion of the UN's Intergovernmental Panel on Climate Change that "most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations." He does this, not with any analysis of his own, but by listing some of the sources of uncertainty that are in any case thoroughly addressed by the IPCC. One wonders whether he has in fact read the panel's reports.

Moving on from his critique of the science of climate change, Lawson argues that even if global average temperature increased by about 3 °C, such warming would be trivial, and even largely beneficial. But given that the difference in temperature between the middle of an ice age and the warm periods in between ice ages is only 5 or 6 °C, an increase of 3 °C , occurring over much shorter time periods — on the scale of centuries rather than millennia — is far from inconsequential. And although they receive extensive coverage in the IPCC reports, Lawson completely ignores some of the most serious impacts of global warming: namely the floods and droughts that are expected to become more frequent and more severe with even small rises in temperature.

Considering the potential for more climate extremes and sea level rise in the future, there are likely to be hundreds of millions of refugees from the world's most affected nations. Where could those people go in our increasingly crowded world? Lawson denies that there is any problem. He repeats a number of times his summary of the damage as the difference between people in the developing world being 8.5 times better off than they are now and the 9.5 times improvement that they would see in the absence of global warming. Sleight of hand with gross numbers of possible economic growth must not be allowed to hide the magnitude of the very real problems. The 2007 IPCC report makes it clear that the anticipated impacts of global warming will lead to tens or hundreds of millions of people suffering loss of resources, livelihoods and land.

But even if such impacts were likely, we cannot afford to address them, says Lawson. To stabilize atmospheric concentrations of greenhouse gases during this century, emissions would have to be substantially reduced from today's levels by mid-century. And because carbon dioxide emitted into the atmosphere remains there on average for around 100 years, there is an urgent need to begin reductions now. Lawson writes this off as being difficult, inconvenient and very costly. But both the International Energy Agency and Shell have recently presented scenarios of changes in energy generation and use by 2050 that show it would be feasible to move substantially towards achieving the emissions reductions required. How great, then, is the cost? The Stern Review on the Economics of Climate Change indicates that if we act quickly, this could be as little as a few per cent of GDP by 2050. Crucially, delayed action will increase the price tag, with the cost of doing nothing and paying to adapt to change much greater than that of early mitigation. Again, Lawson begs to differ, arguing that the financial burden of reducing emissions sharply would simply be unjustified in the face of scientific uncertainty.

Lawson, with rhetorical flourishes, addresses those of us who see more than a 'grain of truth' in global warming and wish to take responsible action towards its mitigation. He lumps us together with a motley mixture of those he labels as eco-fundamentalists or anti-globalization lobbyists. All of us are connected with what he calls a "mountain of nonsense" for which it appears the IPCC is responsible. May I urge Lord Lawson to espouse the cool reason and rigour for which he appears to be campaigning and respectfully suggest that he might begin with a course of reading of the IPCC reports.

Sir John Houghton CBE, FRS is an Honorary Scientist at the Met Office Hadley Centre in the UK.
e-mail: john.houghton@jri.org.uk