A series of leaked emails was leapt on by climate-change deniers to discredit the data, but their efforts may have only slowed the search for solutions

The email that appeared on Phil Jones’s computer screen in November 2009 was succinct. “Just a quick note to encourage you to shoot yourself in the head,” it said. “Don’t waste any more time. Do it today. It is truly the greatest contribution to mankind that you will ever make.”

Nor was it very different from the other emails that were arriving in Jones’s inbox. Others described the climate scientist as the scum of the earth. Some authors promised to kill him themselves. Most of the messages were riddled with obscenities. All made troubling reading.

Facebook Twitter Pinterest Professor Phil Jones of the University of East Anglia. Photograph: Chris Bourchier / Rex Features

As to the cause of this outpouring of hatred, that was straightforward. Jones headed the University of East Anglia’s Climate Research Unit, from which a tranche of emails had just been hacked and made public. These, it was claimed, showed that he and fellow researchers were faking the evidence that suggested our planet was heating up dangerously.

The affair was dubbed Climategate by those who deny the existence of global warming and it remains one of modern society’s most troubling affairs. Many observers believe it helped delay measures that might have slowed climate change and given humanity more time to cut atmospheric carbon dioxide levels, its key cause.

Climategate marks its 10th anniversary this month – an opportune moment to reflect on just how serious was its impact on society, and to look at the effect it had on those who were trying to stop Earth from being ravaged by rising seas, spreading deserts, disappearing coral reefs and suffocating heat.

At the time, climate-change deniers were desperate to find ways to undermine the idea that global warming was real, and as Jones’s unit had provided key data that supported this notion – by showing how land temperatures on Earth had been rising sharply in recent decades – his work was considered fair game. So they responded gleefully by ransacking his hacked emails for signs he may have been fiddling results and asserted, in blogs, they had found telltale signs.

These claims were then picked up by media outlets hostile to global warming. “Scientist in climate cover-up told to quit” ran one headline. “Scientists broke law by hiding climate data”, claimed another.

Jones was vilified. “Within a day or two reporters were outside my house, knocking on my neighbours’ doors, digging for dirt,” he recalls. “I got hundreds of abusive and threatening emails. I knew the accusations were nonsense. But as someone used to being in control I buckled at the loss of it. My health deteriorated. I found it difficult to sleep and eat. I was under intense, spiralling pressure and felt I was falling to pieces. Looking back I suppose I was having some kind of a nervous breakdown.”

So what had Jones said in his emails to trigger these attacks? In one message Jones says he would be emailing a journal “to tell them I’m having nothing more to do with it until they rid themselves of this troublesome editor”. This was interpreted as being a bid to suppress academic criticism. “We’re choosing the periods to show warming,” he says in another email that seems to suggest he was fiddling his data.

Facebook Twitter Pinterest A dried pond in drought-stricken Fuyang, Anhui province, eastern China in October 2019. Photograph: VCG/via Getty Images

And then there was his remark that he was going to employ “Mike’s trick” to use data that would “hide the decline”. In other words, he was going to cover up data that showed the world was really cooling and was not warming, it was claimed.

The Mike in question was Michael Mann, professor of atmospheric science at Penn State University, who had worked with Jones for years. His “trick” was no more than a simple technique to combine the records of temperatures measured directly by thermometer with estimates made from tree rings (which roughly reflect temperature variations).

“In fact, the email was an entirely innocent and appropriate conversation between scientists,” Mann states in this week’s BBC Four documentary, Climategate: Science of a Scandal. He and Jones were merely trying to find appropriate ways of illustrating a graph of global temperature changes.

This view was not shared by Sarah Palin: the former US vice-presidential candidate wrote a Washington Post op-ed article that claimed the emails “reveal that leading climate ‘experts’ … manipulated data to hide the decline in global temperatures”.

British climate science was subjected to huge scrutiny by the world’s best journalists and it stood up to the test Fiona Fox, Science Media Centre

Subsequent investigations by journalists showed these claims were unsupportable, however. Guardian writer Fred Pearce studied the leaked emails and produced a book, The Climate Files, from his research. “Have the Climategate revelations undermined the case that we are experiencing made-made climate change? Absolutely not,” says Pearce. “Nothing uncovered in the emails destroys the argument that humans are warming the planet.”

Pearce was writing for the eco-friendly Guardian, but his views were supported by many others, such as Mike Hanlon, former science editor of the Daily Mail. “Scratch and sniff as we did, there was no smoking gun, no line that would show that there had been a conspiracy to fabricate a great untruth,” he said later. Thus, from the Guardian to the Daily Mail, the notion that Climategate represented “the worst scientific scandal of a generation” – as one UK newspaper had claimed – was found in the end to be unsupportable.

This point is emphasised by Fiona Fox, head of the UK’s Science Media Centre. “British climate science was subjected to huge scrutiny by the world’s best journalists and it stood up to the test. If you look at where we are now in terms of public trust in climate science, it’s hard to sustain the argument that Climategate was fatally damaging to the field.

“Climategate also tells us that front page rows about science are an opportunity as well as a threat and the scientists who stood up in that febrile environment and soundly defended science also did a great job. We need to remember that.”

Facebook Twitter Pinterest New Yorkers brave the severe thunderstorms that hit the city among tornado warnings in May 2018. Photograph: Peter Foley/EPA

Several official UK reports on the affair also supported Jones. One inquiry – by Sir Muir Russell, a senior civil servant – specifically praised the “rigour and honesty” of Jones and his colleagues while another, chaired by Lord Oxburgh, found “no evidence of any deliberate scientific malpractice”. The only real criticism was the suggestion that the researchers had not always shown a “proper sense of openness” in dealing with data inquires.

Jones and colleagues were also backed by the US Environmental Protection Agency which heavily criticised American politicians and energy groups who had tried to use the leaked emails to dismiss the risks facing our overheating world. These individuals had “routinely misunderstood or mis-characterised the scientific issues, drawn faulty conclusions, resorted to hyperbole, impugned the ethics of climate scientists in general and characterised actions as ‘falsifications’ and ‘manipulation’ with no basis or support,” said the agency.

Other powerful support was provided by physicists at University of California, Berkeley, who decided to test if deniers had been right to question Jones’s temperature charts. Led by Professor Richard Muller and backed by funds that included a $150,000 grant from noted climate-crisis denial supporters, the Charles Koch Foundation – the team re-analysed more than 1.6bn land temperature measurements dating back to the 1800s – and came to exactly the same conclusions as Jones: the fairly level temperatures that had continued through the past few centuries began to spike sharply a few decades ago as atmosphere carbon levels rose.

“Our biggest surprise was that the new results agreed so closely with warming values published previously,” said Muller. “This confirms these studies were done carefully and that potential biases identified by climate-change sceptics did not seriously affect their conclusions.”

Such powerful endorsements might have been expected to end deniers’ claims about Climategate. However, they have continued since 2009 to accuse Jones and others of collusion and fraud.

Former Times columnist and climate contrarian Matt Ridley is typical. The “scandal” showed scientists were “conspiring to ostracise sceptics, delete emails, game peer review and manipulate the presentation of data”, he wrote in 2017, ignoring the many reports and studies that in the interim have shown this was not the case.

Note also that since Climategate we have had eight of the warmest years on record; carbon dioxide emissions have continued to rise inexorably; and Arctic sea ice levels in summer have reached record lows over the past decade. Occurrences of heavy rainfall and heatwaves have also increased dramatically. The world has continued to heat up dangerously. Yet humanity has done very little to tackle the crisis.

And that raises a critical question: did Climategate play a role in this failure to act? Some observers believe it did and, as an illustration, point to the fate of the Copenhagen climate summit – organised under the UN framework convention on climate change – which took place only a few weeks after the leaking of the CRU’s emails.

Facebook Twitter Pinterest A sheep farm in New South Wales. The drought across the Murray Darling Basin is now officially Australia’s worst on record. Photograph: David Gray/Getty Images

The Copenhagen summit is widely regarded as a failure. Instead of agreeing on a legally binding treaty to limit carbon emissions as hoped, delegates chose merely to “take note of” an accord drawn up by a core group of heads of state.

So did the leaking of the Climategate emails have a pernicious influence there? Bob Ward, policy director at the Grantham Research Institute on Climate Change and the Environment, doubts it. “Essentially the conference was badly managed. Climategate had very little impact.”

On the other hand, says Ward, climategate did damage public policy-making in the UK and in other western countries. “Rightwing politicians, allied with fossil fuel companies, used their influence to spread false claims about the emails and to argue against policies to cut fossil fuel use. That propaganda campaign still continues today.” The use of illegally hacked emails in Climategate also shows deniers will resort to all sorts of underhand methods to confuse the public, Ward added. “I am sure they would do the same again today – so scientists are going to have to remain vigilant and be ready to fight back at any time.”

This point is backed by Mann, who has fought vociferously to defend climate science in the US. Although the past few years have seen a significant growth in the public’s belief that the world is heating dangerously, climate-change denial has not gone away.

“Hard denial has evolved into something more pernicious,” he says. “Attention has been deflected from imposing policy solutions towards stressing that changes should be made in individual behaviour – people’s diet, methods of travel and other lifestyle choices. It is a classic industry manoeuvre: put the onus on individuals to change things and ignore the need to impose systemic solutions and make policy reforms.

“Of course, individual action needs to be part of the battle, but not as a substitute for policy reform. It should be as an additional component. We must also be aware how the forces of denial are exploiting the lifestyle change movement to get supporters of action against climate change to argue with each other and engage in behavioural shaming. So yes, we will be vigilant in future.”