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N a t u r e l19 9 9

P e t i te ta

:S o u r c e




Atmospher ic perm

(par ts

390 360 330 300 270 240 210 180






6 4 2 0 –2 –4 –6 –8 –10 –12






Age (Thousands of years before present)

Figure 1: Historic CO2 and temperature data from the Vostok ice core


us with a pretty decent picture of how temperatures, sea levels, and the amount of CO2 in the air have changed over the last few tens of millions of years. The results are fascinating – the Earth has swung periodically between colder and warmer periods over the eons (see Figure 1). These huge changes were initially triggered by tiny fluctuations in the Earth’s temperature – the sun might go through a slightly warmer or cooler phase,4 or kinks in the Earth’s orbit might take the planet out a little further or in a little closer.5 The planet would then warm or cool gradually, over hundreds or thousands of years. Then suddenly, this would transform into rapid change, switching the planet from cool to warm or vice versa.

Why the sudden flip into rapid change? Well, as the planet warms up, carbon dioxide and methane are released from plants, soils and oceans. These gases create a greenhouse effect which leads to more warming and thus the release of more CO2 and so on until the whole climate has changed completely. This explains why temperatures started to rise first, and then CO2 followed.

Imagine that a group of gibbons escape and run amok at a zoo. They cause plenty of chaos by themselves, but the zookeepers don’t round them up quickly enough and so the gleeful gibbons started releasing the chimpanzees from their cages, who then start letting the other animals loose, until the whole thing spirals completely out of control. Looking back on this afterwards, it’s true that the zoo was already in chaos before the chimpanzees escaped; but it doesn’t mean that it’s therefore fine to release as many chimpanzees into your own zoo as you like, without expecting any consequences… ‘Many scientists don’t agree with the consensus on climate change’ According to a 2009 survey, 97 per cent of published climate scientists believe that humanity is changing the climate.6 The basic underlying science linking humanity’s greenhouse gas emissions with climate change is as well-established as the link between smoking and lung cancer, or HIV and AIDS – some people still deny these connections, but no-one takes them seriously. There is disagreement and debate around the precise effects of climate change; but the facts that it’s happening, it’s serious, and it’s caused by humans are well established and agreed by all but a small handful of scientists.

Unfortunately, this small group gets a huge amount of attention, making them seem more numerous than they really are – and a lot of this is to do with the funding and support they receive. This isn’t to say that the climate contrarians are simply in it for the money. I’m sure most of them believe in the things they say. But they wouldn’t have such prominence and status without the backing of certain wealthy and powerful individuals, political groups, media outlets and corporations with a (short-term and profit-driven) interest in preventing action on climate change. The mainstream media have a tendency to set up head to head ‘debates’ between climate scientists/campaigners and climate change deniers, which creates the false impression that the science is still disputed. It’s about as useful as watching a debate on how to solve the African AIDS crisis between an experienced Ugandan health campaigner and someone who believes that HIV is spread by evil pixies and can be cured by eating spaghetti.

Quick snippets of falseness #1 ‘So what if ships can get through the Arctic Northwest Passage? It was open in the early 1900s too!’ It ’s true that the Northwest Passage – the icy stretch of Arctic Ocean linking the Atlantic and Pacific Oceans above North America – was first navigated by Roald Amundsen in 1903-1906. Note, however, that it took him three years to get through! This passage used to be completely impassable to ships for most of the year; now, climate change has melted enough Arctic ice to make it an economic shipping route, triggering sovereignty disputes between Canada and other countries.

16 ● N ew I n t e r nat i o nal i s t ● MAY 2 011

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