Smeared scientists must still mend their ways (Financial Times)

December 17th, 2009

Climate naysayers sent out a collective whoop of delight. E-mails hacked from the University of East Anglia’s Climatic Research Unit had proved that the theory of man-made climate change was a scientific conspiracy. “We were right all along!” the bloggers congratulated themselves.

A few weeks after “Climategate”, negotiations in Copenhagen are reaching their conclusion, with no mass lay-offs at scientific institutions and nothing to suggest the layman has given up on climate change. And yet, a sense of unease fills the room when the subject is brought up. So what do the e-mails really tell us?

Ostensibly they called into question the activities of a close-knit group around Professor Phil Jones, director of the CRU. Prof Jones has stepped down while an investigation is carried out. Critics claim that his circle conspired to block rival papers, rig the data and gang up on scientific journals that were not sufficiently gung ho. Sometimes the e-mails’ sense of overarching conviction leads to accidental comedy, such as when the damned weather goes missing: “The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t,” wrote Kevin Trenberth, head of climate analysis at the National Centre for Atmospheric Research in Colorado, and a veteran of the Intergovernmental Panel on Climate Change.

But as is often the case with climate change, nuance and context have vanished. For instance, Prof Jones’s promise to block two rival papers, while deplorable, proved to be bluster – the research was considered by the IPCC after all. The most serious charge is that the CRU’s land surface temperature database, which goes back to 1850 and informs the IPCC reports, is now compromised. Exhibit A is an e-mail from Prof Jones that reads: “I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) and from 1961 for Keith’s to hide the decline.”

It looks bad. But in fact, this has nothing to do with the surface temperature records. It refers to tree ring measurements informing the hockey stick graph that Al Gore made so much of in his film. The hockey stick purports to show how today’s temperatures are unprecedented over the past 1,000 years by using proxy data – tree rings and ice cores – to cover the millennia before the invention of the thermometer. But according to the most respected climate scientists, its importance has been overplayed. The methodology for the hockey stick is opaque, the proxy data not always reliable. Drawing any conclusions from it is problematic.

Myles Allen, head of climate dynamics at Oxford University, explains: “The reason the hockey stick will only ever play a peripheral role in understanding current climate change is that we don’t know what the drivers of climate were before 1900. For instance, we don’t know what the sun was doing back in 1100.” Cautious scientists prefer to restrict the case for climate change to what we know from instrumental data: temperatures have been rising over the past 120 years; carbon dioxide levels have been increasing; and scientists have established that adding carbon dioxide to the atmosphere causes warming.

Mr Trenberth’s “travesty” statement has baffled colleagues. Read in context, it is clear he is complaining that the instruments have failed to pick up the “missing heat” he is convinced is there. The problem here is over-confidence rather than self-doubt. Colleagues point out there is no need to panic over individual years; what matters is the long-term trend. Figures from the US National Climatic Data Centre suggest that the noughties are the warmest decade since records began, while in 2007 Nasa ranked the hottest five years on file as 2005, 1998, 2002, 2003 and 2006.

In short, the e-mails do not undermine the CRU’s surface temperature record or the wider science. But that is not the point – it is the culture of climate science that has been tarnished. A picture emerges of experts who relate tribally, avoid transparency and worry too much about getting a good press. The perception is perhaps unfair, based as it is on a small, activist-minded band, but it goes back to Adam Smith’s remark about producer interests: “People of the same trade seldom meet together, even for merriment and diversion, but the conversation ends in a conspiracy against the public.”

Mr Trenberth insists the e-mail hack equated to a “swiftboating” of climate scientists, a reference to the smearing of John Kerry’s presidential campaign. He argues there is nothing wrong with scientists advocating policy: “I’m a scientist but I’m also a citizen of the world.” He is right that society wants more guidance from scientists. But what we need most is a more nuanced understanding of the risks and probabilities. That requires an intellectual elite who are climate sceptics in the true sense, rather than busily applying blue facepaint and reaching for a placard.

Entry Filed under: Climate change