World has overshot its 'budget' of greenhouse gases this century

The world has emitted extra greenhouse gases this century equivalent to the annual totals of China and the US above a maximum for avoiding the worst of climate change, a study estimated yesterday.

Global accounting firm PriceWaterhouseCoopers said in the report that almost all major nations, including EU countries that pride themselves on climate policies, were lagging since 2000 in a push for low-carbon growth. It said the world was already far above a "budget" of total emissions of 1,300 billion tons of carbon dioxide from

2000-50 which it estimated as the maximum permissible while avoiding the worst of climate change.

"For 2000-08, the cumulative global budget overshoot, or 'carbon debt', is estimated at around 13 billion tons of carbon dioxide - roughly equivalent to the annual carbon emissions of China and the US combined in 2008," it said.

China and the US are the top world emitters of greenhouse gases, mainly carbon dioxide from burning fossil fuels. A conference in Copenhagen from December 7 to 18 will try to work out a new UN pact to curb rising emissions.

"If you stay on this path the entire carbon budget will be used by about 2034, about 16 years early," John Hawksworth, head of macroeconomics at PwC, told Reuters of the report, based on a new PwC Low Carbon Economy Index.

The index is a nation-by-nation tracker of efforts to improve "carbon intensity" - the amount of carbon dioxide emitted per dollar of economic output - rather than the usual yardstick of changes in overall national emissions.

So far this century, the world had improved carbon intensity by only about 0.8 per cent a year, it said.

"To get back on track, world carbon intensity would have to fall by about three per cent a year, four times the speed at the moment," said Richard Gledhill, global leader of climate change at PwC. "That shows the policy challenges."

China's rate of cutting carbon intensity was 0.7 per cent a year from 2000-08, the US 2.2 percent, the European Union 1.8 per cent and India 2.1 per cent. All were lagging the rates set by PwC for their carbon budgets.

It estimated a budget of 1,300 billion tons would give a fair chance of limiting global warming to a two degrees Celsius rise over pre-industrial levels, widely seen as a threshold for "dangerous" change.