The growth in global emissions of carbon dioxide from fossil fuels over the past five years was four times greater than for the preceding 10 years, according to a study that exposes critical flaws in the attempts to avert damaging climate change.
Data on carbon dioxide emissions shows that the global growth rate was 3.2 per cent in the five years to 2005 compared with 0.8 per cent from 1990 to 1999, despite efforts to reduce carbon pollution through the Kyoto agreement.
Much of the increase is probably due to the expansion of the Chinese economy, which has relied heavily on burning coal and other fossil fuels for its energy.
Dr Mike Raupach, chair of the Global Carbon Project, an international collaboration of researchers who compiled the latest figures, warned yesterday that emissions were spiralling out of control.
"This is a very worrying sign. It indicates that recent efforts to reduce emissions have had virtually no impact on emissions growth and that effective caps are urgently needed," he said.
Current levels of carbon dioxide in the atmosphere are 380 parts per million (ppm), about 100ppm higher than before the Industrial Revolution 200 years ago. Some computer models predict damaging and irreversible climate change if carbon dioxide levels rise above 450ppm or 500 ppm.
The rate of increase of emissions suggests it may soon be impossible to avoid some of the worst-case scenarios, said Josep Canadell, executive director of the Global Carbon Project. "On our current path, we will find it extremely difficult to rein in carbon emissions enough to stabilise the atmospheric carbon dioxide concentration at 450ppm, and even 550ppm will be a challenge," he said. "At some point in the near future, we will miss the boat in terms of achieving acceptable levels."
Based on current trends, carbon dioxide concentrations are likely to increase to 500ppm this century. The last time the planet experienced levels as high as 500ppm was about 20 or 40 million years ago, when sea levels were 100 metres higher than today.
The Stern report earlier this month warned that the uncontrolled release of greenhouse gases could lead to a rise in average global temperatures of up to 5C by 2100 - about the same temperature difference between now and the last ice age.
Scientist have warned that global temperatures will continue to rise for many decades after carbon dioxide concentrations have stabilised due to the environmental inertia of the world's climate system.
Dr Peter Falloon, a climate impact scientist at the Met Office's Hadley Centre, said the latest findings did not augur well for attempts at averting climate change.
"It's not what we want or hope to see. The concern comes from the fact that the greater the emissions are now, the harder it will be to bring them down in the future," he said. "It takes 30 or 40 years to realise the change in carbon dioxide emissions. It highlights how important it is to take quick and effective action now."
Professor Bill McGuire, director of the Benfield Hazard Research Centre in London, said: "This is more very bad news. We need a 60 to 70 per cent cut in emissions, but instead, emission levels are spiralling out of control. The sum total of our meagre efforts to cut emissions amounts to less than zero."