End of the world nigh - it's official

Ignore the optimists: the global warming horror stories are all true

Michael Meacher
Friday February 14, 2003
The Guardian

There is a lot wrong with our world. But it is not as bad as many people think. It is worse. Global warming is slowly but relentlessly changing the face of the planet.

We are only in the early stages of this process, but already carbon dioxide in the atmosphere has reached 375 parts per million, the highest level for at least half a million years. Temperatures are projected to rise by up to 5.8 C this century, 10 times the increase of 0.6 C in the last century, and by 40% more than this in some northern land surface areas. This means temperatures could rise by up to 8.1 C in some parts of the world.

Does this matter? The evidence suggests that it does. In China severe floods used to occur once every 20 years; now they occur in nine out of every 10. The number of people affected by floods globally has risen from 7 million in the 1960s to 150 million now. In 1998 two-thirds of Bangladesh was under water for months, affecting 30 million people. In the UK, 5 million people and 185,000 businesses are at risk.

Flooding is only the beginning. The number of people worldwide devastated by hurricanes or cyclones has increased eightfold to 25 million a year over the past 30 years. The oceans are steadily warming, and since they currently absorb 50 times more CO2 than is contained in the atmosphere, even a tiny reduction in CO2 absorption by the sea could cause global temperatures to rise significantly.

Even more seriously, 10,000 billion tonnes of methane (a greenhouse gas 20 times more potent than CO2) are stored, according to the US Geological Survey, on the shallow floor of the Arctic, in sediments below the seabed. If the temperature surrounding the methane warms, it becomes unstable and methane gas is released, causing temperatures to increase further. Warming oceans also cause the waters to expand and the sea level to rise. Sea level is predicted to rise by 3ft over the next century, leading to huge areas of Bangladesh, Egypt and China being inundated.

We don't know the limits of nature - how much rain could fall for how long a period, how much more powerful and frequent hurricanes could become, for how long droughts could endure. The ultimate concern is that if runaway global warming occurred, temperatures could spiral out of control and make our planet uninhabitable.

Five times in the past 540 million years there have been mass extinctions, in one case involving the destruction of 96% of species then living. But while these were the result of asteroid strikes or intense glaciation, this is the first time that a species has been at risk of generating its own demise.

James Lovelock's Gaia hypothesis conceives of the planet as an active control system. It posits the existence of feedbacks at the global level which, so far, have served to keep the earth's surface habitable within a tolerable range, despite significant external changes, including changes in the radiation from the sun. However, with severe human-induced activity, that is now beginning to change.

We have almost become our own geophysical cycle. There are many examples of this trend. On a global scale our biological carbon productivity is now only outpaced by the krill in the oceans. Our civil engineering works shift more soil than all the world's rivers bring to the seas. Our industrial emissions eclipse the total emissions from all the world's volcanoes. We are bringing about species loss on the scale of some of the natural extinctions of palaeohistory.

We face a transformation of our world and its ecosystems at an exponential rate, and unprecedentedly brought about, not by natural forces, but by the activities of the dominant species. Climate change is only the most dramatic example. At a time when scientists say the world should be reducing its CO2 emissions by 60% to stabilise and then reverse global warming, they are projected to increase by around 75% on 1990 levels by 2020.

The dinosaurs dominated the earth for 160 million years. We are in danger of putting our future at risk after a mere quarter of a million years. The force of the Gaia thesis has never been more apparent. When an alien infection invades the body, the body develops a fever in order to concentrate all its energies to eliminate the alien organism. In most cases it succeeds, and the body recovers. But where it does not, the body dies.

The lesson is that if we continue with activities which destroy our environment and undermine the conditions for our own survival, we are the virus. Making the change needed to avoid that fate is perhaps the greatest challenge we have ever faced.

· Michael Meacher is environment minister. This article is based on a lecture he will deliver today at Newcastle University