A new report has warned that the effects of climate change could tip the world's economies into a global recession if governments do not tackle the problem by cutting carbon dioxide emissions.
Launching the report, British Prime Minister Tony Blair said it demolished the last remaining argument for inaction and was the most important document ever put before his government.
Mr Blair said the world was heading towards catastrophic tipping points in its climate unless action was taken.
The report was commissioned by the British Treasury and compiled by former World Bank economist Sir Nicholas Stern.
It argues that the world's developed economies, led by the US, will face far higher costs in future if they do not act now.
Mr Stern predicted that if governments do not take action they will face a massive downturn in their economies. However he also said that confronting climate change may not prove as economically painful as some experts predict.
US President George W Bush refused to join the Kyoto protocol on global emissions because he argued it would harm the US economy.
But this document says that, by acting now, industrial nations could save money.
