Climate: it's worse than we think

Canberra Times
Monday 10/12/2007 Page: 9

The world's leaders must engage in a profound philosophical discussion about our future on this planet, writes George Monbiot

When you warn people about the dangers of climate change, they call you a saint. When you explain what needs to be done to stop it, they call you a communist. Let me show you why. There is now a broad scientific consensus that we need to prevent temperatures from rising by more than 2 degrees above their pre industrial level. Beyond that point, the Greenland ice sheet could go into irreversible meltdown, some ecosystems collapse, billions suffer from water stress and droughts start to threaten global food supplies.

The British Government proposes to cut carbon emissions in Britain by 60 per cent by 2050. This target is based on a report published in 2000. That report was based on an assessment published in 1995, which drew on scientific papers published a few years earlier. Britain's policy, in other words, is based on papers some 15 years old. This target, which is one of the toughest on earth, bears no relation to current science.

Over the past fortnight, both British Prime Minister Gordon Brown and his adviser, Sir Nicholas Stern, have proposed raising the cut to 80 per cent. Where did this figure come from? The last G8 summit adopted the aim of a global cut of 50 per cent by 2050, which means that 80 per cent would be roughly Britain's fair share. But the G8's target isn't based on current science either. In the new summary published by the Intergovernmental Panel on Climate Change, you will find a table that links different cuts to likely temperatures. It suggests that to prevent global warming from eventually exceeding 2 degrees, by 2050 the world will need to cut its emissions to roughly 15 per cent of the volume in 2000.

I looked tip the global figures for carbon dioxide production in 2000 and divided it by the current population. This gives a baseline figure of 3.58 tonnes of CO2, a person. An 85 per cent cut means that (if the population remains constant) the global output for each person should be reduced to 0.537 tonnes by 2050. Britain currently produces 9.6 tonnes a head and the United States 23.6 tonnes. Reducing these figures to 0.537 means a 94.4 per cent cut in Britain and a 97.7 per cent cut in the US. But the world population will rise in the same period. If we assume a population of nine billion, the cuts rise to 95.9 per cent in Britain and 98.3 per cent in the US.

The UN panel's figures might also be out of date. In a footnote beneath the table, the panel admits that "emission reductions. .. might be underestimated due to missing carbon cycle feedbacks." What this means is that the impact of the biosphere's response to global warming has not been frilly considered. As seawater warms, for example, it releases carbon dioxide.

As soil bacteria heat tip, they respire more, generating more CO2. As temperatures rise, tropical forests die back, releasing the carbon they contain. These are examples of positive feedbacks. A recent paper estimates that feedbacks account for about 18 per cent of global warming. They are likely to intensify.

A paper in Geophysical Research Letters finds that even with a 90 per cent global cut by 2050, the 2 degree threshold "is eventually broken." To stabilise temperatures at 1.5 degrees above the pre-industrial level requires a global cut of 100 per cent. The diplomats who started talks in Bali last week should be discussing the complete decarbonisation of the global economy.

It is not impossible. In a previous article, I showed how by switching the whole economy over to the use of electricity and by deploying the latest thinking on regional supergrids, grid balancing and energy storage, you could run almost the entire energy system on renewable power. The main exception is flying (don't expect to see battery-powered jetliners), which suggests that we should be closing rather than opening runways This could account for about 90 per cent of the necessary cut.

Total decarbonisation demands that we go further. Preventing 2 degrees of warming means stripping carbon dioxide from the air. The necessary technology already exists: the challenge is making it efficient and cheap. Last year, researcher Joshuah Stolaroff, who has written a PhD on the subject, sent me some provisional costings, of £256-458 ($A590-1055) per tonne of carbon. This makes the capture of CO2 from the air roughly three tithes as expensive as the British Government's costings for building wind turbines, twice as expensive as nuclear energy, slightly cheaper than tidal power and eight times cheaper than rooftop solar panels in Britain.

But I suspect his figures are too low, as they suggest this method is cheaper than catching CO2, from purpose-built power stations, which cannot be true. The Kyoto Protocol, whose replacement the Bali meeting will discuss, has failed. Since it was signed, there has been an acceleration in global emissions: the rate of CO2 production exceeds the UN panel's worst case and is now growing faster than at any time since the beginning of the industrial revolution. It's not just the Chinese. A paper in the Proceedings of the National Academy of Sciences finds that "no region is decarbonising its energy supply."

Even the age-old trend of declining energy intensity as economies mature has gone into reverse. In Britain there is a stupefying gulf between the Government's climate policy and the facts it is creating on the ground. How can a 60 per cent cut be achieved if new coal plants, new roads and a third runway at London Heathrow Airport are built? Underlying the immediate problem is a mach greater one. In a lecture to the Royal Academy of Engineering in May, Professor Rod Smith of Imperial College explained that a growth rate of 3 per cent means economic activity doubles in 23 years. At 10 per cent it takes just seven years. This we knew. But Smith takes it further.

With a series of equations he shows that "each successive doubling period consumes as much resource as all the previous doubling periods combined." In other words, if our economy grows at 3 per cent between now and 2040, we will consume in that period economic resources equivalent to all those we have consumed since humans first stood on two legs. Then, between 2040 and 2063, we must double our total consumption again. Reading that paper, I realised for the first time what we are up against.

But I am not advocating despair.

We must confront a challenge that is as great and as pressing as the rise of the Axis powers of the 20th century. Though the war often seemed impossible for the Allies to win, when the political will was mobilised strange and implausible things began to happen. The US economy was spun round on a dime 1942 as civilian manufacturing was switched to military production. The state took on greater powers than it had exercised before. Impossible policies suddenly became achievable.

The real issues in Bali are not technical or economic. The crisis we face demands a profound philosophical discussion, a reappraisal of who we are and what progress means. Debating these matters makes us neither saints nor communists - it shows only that we have understood the science.

George Monbiot is a columnist with the Guardian.