Global warming has become something of a fashion. To gainsay it is a political cyanide pill akin to older variants of the likes of ‘abolitionism’ or ‘free trade’. The climate is changing, and it’s all our fault. One need only look at the success of a film like Al Gore’s An Inconvenient Truth to see how this basic principle has become an accepted fact. Recent films like The Day After Tomorrow illustrate how mainstream such ideas are. It’s a big issue, it’s an important issue, and it’s politically and financially loaded. Which is why it is all the more important it isn’t swallowed wholesale. A recent Channel 4 production hoped to show just how deceptive the issue can be.

globalwarming_1.jpgUnfortunately, it is very easy in this ‘information age’ for facts to become distorted and blown out of proportion, particularly by the mainstream media. On a daily basis, news programmes bring us the latest breakthroughs from the cutting edge of science. In Britain this is concomitant with a constant tugging on our heart strings to force the NHS to accept the latest miracle cure for cancer, Alzheimer’s or any other myriad diseases. Of course, the problem is that breakthroughs at the cutting edge of science have a tendency to go wrong, the results of surveys tend to be disproved by later surveys, and false conclusions tentatively fed to the public with phrases like ‘scientists believe’ and ‘recent surveys have shown’ in fact get swallowed as gospel fact.

Such is the problem with the current furore over global warming. Whilst there are some essential facts which can be agreed upon by all parties, the basic link between carbon dioxide emissions from the burning of fossil fuels and the warming climate has been virtually set in stone in people’s minds. Yet the evidence is neither conclusive, nor necessarily indicative of human involvement in the current warming climate. Which is what Channel 4’s The Great Global Warming Swindle set out to illustrate. Whilst it is undeniable that the climate is always changing, it is also undeniable that the climate has changed without our interference. The programme points out that within our written history, the climate has been both much cooler and warmer than it currently is. Documentaries of the sixties and early seventies talked more about the threats of global cooling than global warming, with the potential for another mini-Ice Age should trends continue.

Yet looking further back in history, there have been periods when the climate has been warmer than it is now. The programme pointed out that evidence for this remains with us in the number of wine-related place names in the United Kingdom, the Vine Streets of its towns. This leads us to ask, why are we so sure that climate change is being caused by our activities? The assumption seems to be that the planet’s carbon cycle acts like some giant thermostat to the global climate—turning up the atmospheric carbon content through deforestation and the burning of fossil fuels will cause the climate to warm. Of course, there is no chicken and egg situation in the fossil fuels stakes, which means that when our imaginary thermostat is on full, then life must have found a happy equilibrium in which to sequester itself in pockets which man is today uncovering.

That carbon dioxide is a greenhouse gas is undeniable. That it is the main cause of the global climate, however, is a pretty big jump in logic. The show pointed out that whilst CO2 levels have risen pretty constantly through the past two centuries of human industrial activity, temperatures have fluctuated much more erratically. In particular, the post-war boom years of industrial activity saw a drop in temperatures which seems to go against the accepted trend. Of course, as a proportion of Earth’s atmosphere, CO2 accounts for a miniscule proportion, usually measured in parts per million, which is generally considered to have risen around 40% as a result of man’s actions. Yet these levels have fluctuated even without man’s interference, according to the data we have available, and on an annual basis man’s contribution to the atmospheric CO2 content is far outweighed by natural processes, largely as a product of respiration (coming particularly from the oceans) or from volcanic eruptions. According to the figures available, the correlation between temperature and carbon dioxide levels is indeed linked, but the pattern shows that carbon dioxide levels actually follow changes in temperature by a lag of around 800 years. ((This was suggested to be the length of time it takes the world’s oceans to react to changes in temperature, for the same reasons which make maritime climates much less extreme than continental ones.)) Furthermore, carbon dioxide is one of the weaker ‘greenhouse gases’, both methane and water vapour for example have a more potent effect. And how much faith can we take in ice cores for giving accurate atmospheric CO2 levels and temperatures in the first place?

The Great Global Warming Swindle does offer some alternatives to the greenhouse gas theory. Essentially all of the suggestions boil down to fluctuations in the sun’s activity, giving the programme the unfortunate appearance of a reassuring panacea. Fluctuating solar activity not only changes the amount of energy being received by the Earth, but can also affect the reception of cosmic rays via so-called solar winds. The programme played upon the suggestion that these cosmic rays are in part responsible for cloud formation, which blocks out solar radiation and cools the atmosphere; more solar winds result in fewer cosmic rays reaching Earth, fewer clouds forming, and therefore a warmer climate. All interesting theories, but these suggestions only detracted from the programme’s important message, that the global warming theories that are today largely accepted as facts need questioning. Combined with a focus on the politics of scientific financing (although arguably an important issue to raise), the programme unfortunately smacked of ‘conspiracy theory’ far more than it probably should. Here’s to hoping that it got at least a few people thinking.