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Analysis CLIMATE CHANGE DENIAL N a t u r e l19 9 9 P e t i te ta :S o u r c e ) 2illion CO Atmospher ic perm (par ts 390 360 330 300 270 240 210 180 CO2 Temperature )(˚C lies Anoma 6 4 2 0 –2 –4 –6 –8 –10 –12 Temperature 400 300 200 100 Age (Thousands of years before present) Figure 1: Historic CO2 and temperature data from the Vostok ice core 0 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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Myths about temperature rise ‘The world isn’t really warming up’ The first graph on the right shows the global air temperature over the last 150 years; the second adds in the ocean temperature since 1950. So the temperature changes we are feeling on land are small fry (if you’ll pardon the expression) compared to the heating of the oceans. Meanwhile, cyclical weather patterns like El Niño and La Niña move heat back and forth between the oceans and the air in an irregular fashion – a major reason why atmospheric temperatures aren’t rising in a nice neat line. For example, a strong El Niño shifted a lot of heat from the seas into the air in 1998, causing a spike in air temperatures. When temperatures in the following years reverted back, climate deniers started going on about how global warming had ‘stopped’. Of course it hadn’t – it was just that the heat was being stored in the ocean rather than the atmosphere, as Figure 3 clearly shows. The top ten hottest years in recorded human history all happened in the last twelve years, with 2005 and 2010 tied for the hottest ever.9 ‘The world cooled down between 1940 and 1970’ This isn’t true, but is based on something genuinely interesting. Global warming did plateau for a bit between the 1940s and the 1970s, due to the phenomenon of ‘global dimming’ – a type of industrial pollutant called sulphate aerosols were partially blocking the sun’s rays. This lasted for a while until the ongoing build-up of greenhouse gases – combined, ironically enough, with a reduction in sulphate pollution from power stations – eventually swamped the dimming effect and the temperature began to rise once more.10 You can see this flattened period on the graph in Figure 2. ‘The temperature data are fixed/flawed/ manipulated’ To somehow tamper with or subvert the data from around 7,000 different measurement stations and satellites, which are processed via three different major organizations with hundreds of staff, would require an utterly fantastic level of conspiracy. Nonetheless, in 2010 a procession of (mostly online) commentators claimed that a series of hacked emails from the Climate Research Unit at the UK’s University of East Anglia contained evidence of just such a conspiracy (which they imaginatively dubbed ‘Climategate’). Three separate independent enquiries trawled through the emails and found evidence of nothing more than a few scientists occasionally 0.4 0.2 )(˚C ly Anoma Temperature 0 –0.2 –0.4 –0.6 –0.8 1860 1880 1900 1920 1940 1960 1980 2000 Figure 2: Global warming since 1850, an average computed from ten different sources. The ‘0’ line is the 1990 - 2000 average temperature l i c e n c e CC u n d e ra . c o m i e n c e l s c . s k e p t i c a w w w f r o m g r a p h af r o m A d a p t e d :S o u r c e les) (1021Jou ly HeatContentAnoma 220 200 180 160 140 120 100 80 60 40 20 Land & Atmosphere Heating Ocean Heating Ocean Heating 0 –20 Land & Atmosphere 1950 1960 1970 1980 Figure 3 – Total Earth heat content from 1950 1990 2000 being a bit rude about some of their colleagues, using some unhelpful jargon and having the odd moan about incessant public requests for information.11 However, there was one useful outcome: much more of the raw temperature data has since been made public, to avoid similar accusations in the future.12 ‘But it’s cold today…’ Although the average global temperature is rising, that doesn’t mean that everywhere is getting hotter at the same rate. The global climate system is complicated; some places are heating faster than others, and some may even cool down depending on ocean currents and wind patterns. The difference between climate and weather is important here. Climate change is a gradual, l2 0 0 8 8 , e ta i n g u e s l2 0 0 97,D o m l i c e n c e CC u n d e ra . c o m i e n c e e ta l s c :M u r p h y s k e p t i c a S o u r c e s b y g r a p h N ew I n t e r nat i o nal i s t ● MAY 2 011● 17

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Analysis CLIMATE CHANGE DENIAL

N a t u r e l19 9 9

P e t i te ta

:S o u r c e

)

2illion

CO

Atmospher ic perm

(par ts

390 360 330 300 270 240 210 180

CO2

Temperature

)(˚C

lies

Anoma

6 4 2 0 –2 –4 –6 –8 –10 –12

Temperature

400

300

200

100

Age (Thousands of years before present)

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

0

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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