Calling for "bold and decisive action," British Prime Minister Tony Blair has endorsed a new report that warns failure to act on climate change could trigger a worldwide economic slowdown along the same level as the Great Depression.

Written by former World Bank economist Sir Nicholas Stern at Blair's request, the 700-page report was released on Monday.

Speaking about the Stern review into climate change at the Royal Society in London, British Prime Minister Tony Blair called for bold and decisive action.
(CBC)

"Our actions over the coming 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," says the report.

Blair quickly endorsed the report, saying the consequences of ignoring climate change would be disastrous.

"And this disaster is not set to happen in some science fiction future many years ahead, but in our lifetime," he said.

Economy will shrink: report

The report warns that unless the issue of climate change is immediately addressed, global economic growth could shrink by 20 per cent and cost the world economy close to $7 trillion US.

The report suggests other effects could include:

• 200 million new refugees as people are displaced by severe flooding or droughts.
• Water shortages for one in six people.
• A spike in world temperatures of up to 5 C.
• Melting glaciers that could lead to water shortages.
• The extinction of 20 to 40 per cent of wildlife species.

The international community must spend one per cent of global gross domestic product (GDP) to address the issue of climate change within 10 to 15 years, said Stern.

"Action is urgent since stocks of greenhouse gases are rapidly approaching dangerous levels," said the report.

Many environmentalists believe capping greenhouse gas emissions is key to tackling climate change.

Among the measures Stern advises are stabilizing greenhouse gas levels by decarbonizing the power sector by as much as 70 per cent through new energy sources, eliminating deforestation and cutting transportation emissions, especially from aircraft.

Stephen Smith, an economic professor at University College London, said the report is a "solid review of the range of things that could happen" if climate change is left unchecked.

"I think it's a very serious and … thoroughly argued report with … very detailed and serious evidence," said Smith. "I think it will have a big impact on thinking in Europe and elsewhere."

Blair proposes new European targets

The report is expected to increase pressure on the Bush administration — which never approved the Kyoto Protocol climate change accord — to step up its efforts to fight global warming. Washington says it can't buy into a deal that hasn't been signed by two of the world's biggest polluters, India and China.

Kyoto targets call for a reduction of greenhouse gas emissions of 5.2 per cent from 1990 levels by 2012. Canada agreed to a slightly higher target of six per cent, a goal the federal government says it can't reach.

Blair, who will leave office within a year, called for "bold and decisive action" on the issue.

"The Stern review has done a crucial job. It has demolished the last remaining argument for inaction in the face of climate change," said Blair.

"We know now urgent action will prevent catastrophe and investment in preventing it now will pay us back many times."

Blair called for Europe to cut its carbon dioxide emissions by 30 per cent by 2020 and 60 per cent by 2050. The British government is considering new "green taxes" on cheap airline flights, fuel and high-emission vehicles.

Blair also said his government has enlisted the support of former U.S. vice-president Al Gore to promote the issue in North America. Gore recently produced An Inconvenient Truth, a documentary on climate change.

The report comes days before United Nations talks on climate change in Nairobi on Nov. 6, which are aimed at finding a successor to Kyoto.

With files from the Associated Press