Johann Hari is very good in today’s Independent addressing some of the myths perpetuated by global warming deniers.
Deniers’ Myth Number One: Scientists are divided on whether man is causing global warming. In 2004, the universally-respected journal Science studied 928 randomly selected scientific papers containing the words “global climate change”. None of them - not one - disagreed with the view that global warming is being caused to a significant degree by burning fossil fuels. As Jim Baker, who was head of one of the leading scientific organisations in the US, explains, “There is a better scientific consensus on this issue than any other, with the possible exception of Newton’s Law of Dynamics.”
Deniers’ Myth Number Two: The current warming of the world is simply part of the planet’s natural cycle. After all, there were no carbon emissions when the last ice age ended - why should the current warming be due to them? There is a sliver of truth in this: natural climate change has not stopped, and it never will. But we have superimposed onto it a great blast of greenhouse gases of our own, with far stronger effect.
To understand this, you only have to grasp some basic 19th-century physics. As Professor Chris Rapley of the British Antarctic Survey explains, “There are natural greenhouse gases in the earth’s atmosphere which trap heat on the planet, keeping the surface temperature 30 degrees warmer than it otherwise would be. Since the start of the industrial revolution, we have released lots more greenhouse gases - around 1,000 billion tonnes of them. This has enhanced the natural greenhouse effect, and trapped more heat - currently 0.6 degrees. The more greenhouse gases we add, the warmer we’ll be. It’s not rocket science.”
Deniers’ Myth Number Three: The current warming in the world is all due to changes in the energy output of the Sun. In 1991, the Danish scientists Knud Lassen and Eigil Friis-Christensen found a correlation between temperature changes on Earth from 1850 onwards and sunspot activity, which usually indicate changes in the intensity of solar radiation. As the sun warmed, we warmed.
Other scientists studied this closely, and found out that they were partly right: up to 40 per cent of the planet’s warming is indeed due to solar activity. But since 1980, sunspot activity has been declining - yet temperatures down here have been soaring to the highest levels ever recorded. So while the Sun can take some of the flak, the world’s scientists agree: the other 60 per cent remains with us.
Deniers’ Myth Number Four: In the 1970s, scientists were warning about “global cooling” and a looming Ice Age. How can we now trust these warnings of global warming? In fact, in the 1970s two - literally two - scientists tentatively suggested that cooling could occur over millennia. To compare that meek, misreported suggestion by two people to the overwhelming scientific consensus from tens of thousands of climatologists is, I am sure you deniers can see now, dishonest.
Denier’s Myth Number Five: Global warming is a religion. People have always had an innate psychological need to believe in a looming apocalypse - this is just the latest version.
Precisely the opposite is the truth. Global warming is based on very close empirical observation of the real world, and deductions based on reason. If its conclusions fall into one particular niche in intellectual history, that doesn’t change the fact they are true. It is you, the deniers clinging to myths, who resemble the faithful. Far from being Galileos, you have been siding with the fossil fuel Vatican.
Quite so. These aren’t the only myths that are repeatedly trotted out by the global warming deniers, of course. My favourite is that since weather forecasters can’t predict the weather more than a few days ahead with any reliability, the predictions of climatologists are inherently unreliable. It sounds plausible at first, but is based on a fundamental misunderstanding of the difference between ‘climate’ and ‘weather’ — weather is what is happening here and now. Climate, on the other hand is an essentially statistical science. We may not be able to predict the weather reliably for the day after tomorrow, but that doesnâ€™t preclude the possibility of making predictions for the climatic trend for the next 100 years. A simple example will suffice. If you toss a coin, you cannot predict the outcome. Itâ€™ll be heads, tails or neither (in the extremely unlikely, but entirely possible event that the coin comes to rest on its edge or gets plucked away by a passing jackdaw ). However, if you toss a coin 1000 times the outcome will be more or less 500 heads and 500 tails. You can predict that with a reasonable degree of certainty. Thatâ€™s the difference between climate and weather.
The reality is that almost every day there is further evidence confirming that human activity is having a profound effect on the world’s climate. Even George Bush is beginning to get it.