Credit: Goddard Institute of Space Studies
JAMES HANSEN IS NOT an easy man to pin down. He may be the world's most renowned climate scientist, and almost certainly its most confrontational, but he keeps his tracks well camouflaged.
His office is situated in an anonymous and shabby brownstone apartment block on a side-street, off New York's Upper West Side. It is above Tom's Diner, the restaurant that achieved fame in the TV comedy series Seinfeld. Thousands of tourists swing by here every year, but most pay little attention to the crumbling doorway beside it.
This entrance turns out to belong to NASA's Goddard Institute of Space Studies where Hansen, its director, and his staff analyse the impact of greenhouse gases using data relayed from thousands of collection points around the world, including satellites and polar bases.
These have shown that our planet has gone through a 0.6ºC rise in temperature since 1970, with the 10 hottest years having occurred between 1997 and 2008: unambiguous evidence, Hansen believes, that Earth is beginning to dangerously overheat thanks to the carbon dioxide we are pumping into the atmosphere.
He turns out to be a dry, soft-spoken, rather self-effacing man who, in his green jumper with elbow pads, cords and check cotton shirt, has the look of a careful, tweedy academic. His office is dominated by a battered black-leather sofa, mounds of paperwork, an old globe of the Earth and large, dusty bookcases that cover three walls. Both room and occupant exude old-fashioned studiousness.
This is no out-of-touch academic, however. Hansen appeared in Al Gore's film, An Inconvenient Truth, and is a winner of the World Wide Fund for Nature's top conservation award. He has also proved to be a remarkably doughty opponent of those who deny the dangers of global warming, including the administration of President George W. Bush, which, rashly and unsuccessfully, attempted to censor Hansen's warnings.
For such individuals, and the rest of the world, Hansen has a terse and unambiguous message about the dangers posed by industrial carbon emissions, particularly those produced by coal - by far the dirtiest, most dangerous emitter of greenhouse gases.
"Coal is the single greatest threat to civilisation and all life on our planet," he states. Coal-powered electricity stations are "factories of death". It is a blunt message and the physicist has gone to considerable pains to make sure the world hears it. Apart from his rows with Bush, his appearances before U.S. Senate committees and his TV interviews, Hansen has flown round the world to support the causes of dozens of climate-change protesters.
And then there are those letters to leaders of the U.S., France, Britain, Germany, Japan and Australia - presidents and prime ministers who have been told, in no uncertain terms, of the error of their ways. For example, Hansen recently wrote to Australia's Kevin Rudd to tell him "your leadership is needed on a matter concerning coal-fired power plants, a matter with ramifications for life on our planet." Halt all construction of coal-power plants, he urged Rudd, a message that seems to have fallen on deaf ears.
"The current Australian government was elected on a platform that it was going to deal with climate change, which was clearly having an effect on the country. But what it has done - thanks to industry which has a powerful influence there - is set the goal for limiting carbon dioxide emissions so high, it guarantees there will be no effective reductions on emissions," says Hansen, a message he has repeated in several more letters to the Australian government in 2009.
Furthermore, Australia is exporting coal to China at a rapid rate, he says. "The country claims to be climate concerned, but it is just another example of 'greenwash'."
Greenwash turns out to be a favoured Hansen phrase, a term that precisely encapsulates his disdain for those who talk the eco-talk but fail to walk the eco-walk when it's time for action. "So many governments and businesses say the right words, they talk green, but their actions don't correspond."
Hansen's uncompromising stance on this issue stems, in part, from his training - as a planetary physicist, a scientist who sees our world in its entirety and understands its global problems.
"My father was a tenant farmer in Iowa which, by good luck, was a state that was keen on helping young people, with little money, to go to university. I was good at science and mathematics at school and went to Iowa University to study at its physics department."
It was a fortuitous move. The department was then run by James Van Allen, the physicist who used data from the first U.S. satellite, Explorer 1, to discover Earth's radiation belts (which are named after him), and who is considered among America's most distinguished 20th century scientists. Hansen could not have had a better mentor. "I was very lucky. It was a great environment," he recalls.
At this time, the U.S. government was still reeling from the shock of the launch of the Soviet satellite Sputnik and was anxiously promoting science in its colleges so its technology would be able to compete with that of the Societ Union.
Respected researchers like Van Allen were provided with lavish grants and told to find, and fund, America's most promising young scientists. Van Allen picked Hansen as one of his choices and offered him a postgraduate post at Iowa. "He told me that new microwave data from Venus suggested that either its ionosphere was behaving in a very odd fashion or it was an extremely hot planet. This was before any probes had landed there, of course."
Hansen's analysis of Venus's microwave signals helped to prove that the latter case was true and that Venus's surface temperature reaches several hundred degrees Celsius - hot enough to melt lead. These hellish conditions exist because Venus's atmosphere is replete with extraordinarily high levels of carbon dioxide. These trap energy from the Sun and heat the planet dramatically.
"Most of Venus's carbon dioxide is in its atmosphere. On Earth, most of our carbon dioxide is in the ground or in the ocean. However, if we get a runaway greenhouse effect here, thanks to our industrial carbon emissions, then we may end up with a lot more of our carbon dioxide in the atmosphere and a planet that is uninhabitable."
After this research, Hansen turned his interests away from Venus and back to Earth, developing techniques for analysing data from the increasing number of Earth-monitoring satellites that were launched by the United States. In the end, this work led to him working at the Goddard Institute of Space Studies where he took over the directorship in 1983.
By this time, Hansen had already learned that there could be consequences for speaking out on issues that might have political ramifications.
In 1981, he wrote a paper about the dangers of global warming that was published in the U.S. journal Science - it was one of the first ever written on the topic. And to make sure the world knew about it, he sent a copy to The New York Times, which ran a story about his work.
The U.S. department of energy was furious; several of its senior scientists denounced Hansen for being alarmist, and his funding was slashed. "They simply didn't want that sort of attention to this problem, because it had big implications for the fossil fuel industry."
The decision is not without irony, however. "Climate change deniers always say researchers only make these dire warnings to get grants for themselves," says Hansen. "In fact, in my experience, it gets them taken away."
Hansen was not to be silenced, however. In 1988, he stunned a congressional hearing, on a particularly hot, sticky day in June, when he announced he was "99 % certain" that global warming was to blame for the weather and that the planet was now in peril from rising carbon dioxide emissions. His remarks, which made headlines across the U.S., pushed global warming on to diplomatic agendas for the first time.
And so Hansen continued with his pronouncements until, in 2005, he gave a talk at the American Geophysical Union in which he argued that the year was the warmest on record and that industrial carbon emissions were to blame.
By now George W. Bush was in power and a furious White House told NASA that it had to ban Hansen from appearing in newspapers or on television or radio. It caused "a shit-storm at the agency" admits Hansen.
In the end, though, the White House's bid to censor the scientist failed spectacularly after newspapers revealed that attempts were being made by administration officials to have Hansen silenced. His story, along with his warnings about the climate, got global - not just national - coverage.
Hansen, a member of the U.S. National Academy of Sciences, was under no illusions about what was going on. The attempt to silence him was just one episode in a widespread campaign that took place under Bush, he says, one that was completely detrimental to democracy.
Political appointees were put in charge of the public affairs offices of the space agency NASA, the National Oceanic and Atmospheric Administration and the Environmental Protection Agency in a straightforward attempt to stifle the voices of those scientists who were trying to reveal that old inconvenient truth: that the planet was heating up because of mankind's own activities.
Thanks to Hansen and his established rapport with the media, however, these hamfisted attempts did not go unnoticed. Whether they will continue or not with a new U.S. administration - seemingly more sympathetic to science - is a different matter. "We will soon find out though," he says.
Hansen is generally supportive of new U.S. President Barack Obama, however - although he accepts that the task awaiting him is an enormous one. Certainly, the U.S. can no longer ignore the dangers to the planet from its rising carbon dioxide emissions. "America must now take the lead," he says. "We have only four years left for Obama to set an example to the rest of the world. I am an optimistic person by nature, but this will be the real test of it. One thing I am certain of is that before the end of Obama's first term, we will see new record temperatures being set."
More to the point, these records will continue to be broken, a trend - says Hansen - that is written in the climatic history of the Earth. When we look at the onset and subsequent decay of Ice Ages, we see an imbalance, he points out. "Warming happens more quickly than cooling. Ice sheets fall apart quickly but take a long time to build up." The latter takes tens of thousands of years, but a warming can take less than a thousand years. The planet, it seems, can heat up very fast.
That is, without humanity's interference. Now add the billions of tonnes of carbon dioxide that we are pumping into the atmosphere from our factories, power stations and cars, and we can see we are pushing the world towards a dangerous tipping point.
"Over the past couple of hundred years, we have been burning all the fossil fuels laid down throughout Earth's history," adds Hansen. "That is unprecedented and it is destined to have a very serious impact if we continue that combustion."
As to Hansen's particular antipathy to coal - as opposed to other fossil fuels - that is based mostly on pragmatic concerns. "There are a lot of oil and gas deposits left but there is no way to avoid using them up," he says.
"They are owned by countries such as Russia and Saudi Arabia and they are clearly going to sell them or use them. We can deal with that. What we have to solve is the problem of the world's vaster, dirtier reserves of coal. We have to learn to sequester its emissions and bury them, or just not use coal at all, if we want to preserve a climate that resembles the one in which civilisation developed."
Crucially, if we do not act, the main impacts - melting ice sheets, spreading deserts, climate destabilisation, drowned landscapes and rising sea levels - will be felt by our children and grandchildren, he argues. Hence, Hansen's decision to send a letter, outlining the threat posed by climate change, to Obama when he took office in January 2009.
That document, we should note, was signed by both Hansen and his wife Anniek and was addressed to Barack and Michelle Obama. "It was appropriate. Women are concerned about their children and grandchildren," he says.
So is Hansen, of course. Along the one wall of his wood-panelled office that is not covered with bookcase, he has pinned 10 large photographs of his three grandchildren: Sophie, Connor and Jake. They are the only personal items on display in an office otherwise dominated by stacks of manila folders and cardboard boxes filled with reports.
But these images are more than mere expressions of familial love, he stresses. They are reminders to the 68-year-old scientist of his duty to future generations. "I have been described as the grandfather of climate change. In fact, I am just a grandfather and I do not want my grandchildren to say that grandpa understood what was happening but didn't make it clear."
Given Hansen's track record, nobody could every really accuse him of that.
A POINT WELL MADE
A startling indication of Hansen's impact on international efforts to combat global warming is provided by the case of the Kingsnorth Six. In October 2007, British eco-campaigners occupied parts of the Kingsnorth coal power station in Kent, England. They were protesting about plans, by the power company E.On, to replace the station with a new, larger coal plant, a proposal that was supported by John Hutton, the British cabinet minister responsible for energy.
By occupying Kingsnorth, the group forced its closure for a day. Six of them were charged with causing criminal damage. So their lawyer asked Hansen to help. He agreed, testifying in court that by closing the plant for 24 hours, the group had prevented 200,000 tonnes of carbon dioxide from entering the atmosphere. Far from causing criminal damage, the group had helped prevent widespread environmental destruction, he argued. The jury agreed and acquitted the six protesters at the trial in September 2008. Within a month, Hutton was moved to a new government post and a new British policy towards coal power was adopted: only plants that can capture their carbon dioxide emissions - so they can be stored underground by carbon capture and storage technology - should be built in Britain in future.
Robin McKie is a contributing editor of Cosmos, based in London. He is the science editor of the Britain's The Observer.
