$7-trillion warning on global warming


Leading economist says climate change will cost more than two world wars and Great Depression combined




Global climate change will cost the world economy as much as $7-trillion in lost output and could force as many as 200 million people out of their homes because of flood or drought unless drastic action is taken by governments worldwide, a report to the British government says.

Prepared by Sir Nicholas Stern, the World Bank's former chief economist, the report is not due out officially until today, but publication of its highlights during the weekend has already created shock waves. Commissioned by Britain 's Chancellor of the Exchequer, Gordon Brown, it is considered significant because it is the first such contribution to the international debate on global climate change that comes not from a scientist but an eminent economist. But it is sure to spark criticism from climate-change skeptics. A group of nine British economists, including former British cabinet minister Nigel Lawson earlier described the Stern study as "a misdirected exercise."

In the 700-page report, Sir Nicholas warns of the cost of uncontrolled climate change caused by soaring greenhouse gas emissions.

"Our actions over the coming few decades could create risks of major disruption to economic and social activity later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century," Sir Nicholas writes.

Canada signed up to the Kyoto agreement and agreed to reduced greenhouse gas emissions by 6 per cent below its 1990 levels between 2008 and 2012. Instead, those emissions are up considerably and the Conservative government has conceded it won't come close to meeting those commitments.

The report suggests that 1 per cent of global domestic product be spent immediately on dealing with climate change, to avoid higher costs later. Failure to act would lead to a drop of 5 to 20 per cent of global GDP and make large swaths of the Earth's surface uninhabitable.

Even if the pace of growth of emissions did not rise beyond current levels, the level of gases in the atmosphere would double preindustrial levels by 2050 to 550 parts per million. And based on current trends, average global temperatures will rise by two to three degrees Celsius within the next half century compared with where they were prior to 1850.

It also warns that the developing world will be hit first and hardest and that the richer countries have a responsibility to help them adapt.

Sir Nicholas argues that spending money now on measures to reduce greenhouse-gas emissions will pay for themselves many times over.

But he concludes that even with this spending, the world cannot escape all the damaging consequences of climate change.

In an effort to control the growth of greenhouse-gas emissions, radical action is required, including reducing the carbon emissions of the electric-power sector of the world economy by 60 to 70 per cent and an end to all deforestation.

The report estimates that deforestation already accounts for 18 per cent of global emissions.

Britain 's Environment Secretary, David Milband, said that until now the debate on global climate change has been dominated by moral and scientific arguments.

"Now it is being joined on economic grounds. Up to 20 per cent of GDP of industrialized countries like this -- think of the enormous economic impact that would have," Mr. Milband said.

"The science tells us that we have got 10 to 15 years to radically change the way in which we produce energy and fuel," he added. Reports say that the British government is considering a series of measures to reduce greenhouse gas emissions, including a carbon tax, and higher gasoline taxes.