Free Radicals - Michael Brooks [106]
But it is only doing nothing at all that is truly futile, Hansen believes. That is why, in 2004, at the age of sixty-three, he embraced life as a climate change activist. Two years later, Time magazine named him as one of America’s 100 most influential people. That was also the year that Hansen got himself arrested for the first time. Just doing science, he says, is no longer enough.
It’s not as if he hasn’t done enough science. Hansen is one of planetary science’s most respected researchers. He has a hugely prominent role as the director of NASA’s Goddard Institute for Space Studies, and he is also a professor at Columbia University. He has won numerous awards for his research. Hansen knows, more than anyone, what happens when a planet is in thrall to global warming.
Take a look up into the sky the next time Venus is visible. You won’t be looking at its surface: the planet is cloaked in clouds of sulphuric acid and, beneath that, carbon dioxide. Under this thick, stifling atmosphere, the surface of Venus is a barren waste that bakes at temperatures above 450 degrees Celsius. Venus is often referred to as the Earth’s twin: its diameter is just 5 per cent less than the Earth’s, and it has around four-fifths of the Earth’s mass. James Hansen’s mission in life is to make sure that those remain the only similarities.
Hansen is one of the scientists who worked out that the searing surface temperature is due not only to Venus’s proximity to the Sun, but also to the blanketing effect of the carbon dioxide atmosphere. Knowing this made him deeply concerned about reports that the amount of carbon dioxide in the Earth’s atmosphere was growing.
In 1988, the US Congress asked Hansen for an opinion on the ‘greenhouse effect’. Some of the Sun’s energy that hits our planet is reflected back from the surface. Carbon dioxide and other greenhouse gases absorb some of this reflected energy, preventing it from radiating back into space. A few scientists had begun to warn that increasing amounts of carbon dioxide in the atmosphere would result in rising temperatures on the Earth. If the balance of energy in versus energy out became too skewed in the wrong direction, the atmosphere could eventually heat to disastrously high temperatures.
Hansen’s response to Congress was uncompromising. Aware of the claims, he had already stopped studying the atmosphere of Venus and started studying the atmosphere closest to home. ‘The greenhouse effect is real,’ he told Congress, ‘it is coming soon, and it will have major effects on all peoples.’ The scientific evidence for this, he said, was ‘overwhelming’.
This is not the place to go into the details of claims and counter-claims about global warming (I would recommend Hansen’s books for that), but Hansen’s testimony to Congress, which stated that human activity is responsible for increased levels of carbon dioxide in the atmosphere, triggered a backlash from the industries, such as power generators and motor vehicle manufacturers, that were linked with carbon dioxide emissions. That backlash, and the political fallout, is continuing.
Right at the centre of the controversy is the IPCC – the Inter-governmental Panel on Climate Change. It is a Nobel Prize-winner: the 2007 Nobel Peace Prize was awarded jointly to the IPCC and Al Gore ‘for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change’. But it is clear to many that the IPCC could do better. The influential physicist and climate activist Joseph Romm summed up the problem thus: ‘Most scientists – and the IPCC in particular – have tended to overemphasize uncertainty on the key issues.’
Like the panel on alien communications at the Royal Society’s Kavli Centre, the IPCC is keen not to be seen as too troublesome when faced with public scrutiny. For all the