Britain issued a call for urgent action on climate change on Monday (October 30) after a hard-hitting report painted an apocalyptic picture of the economic and environmental fallout from further global warming. The report said failing to tackle climate change could push world temperatures up by 5 degrees Celsius (9 Fahrenheit) over the next century, causing severe floods and harsh droughts and potentially uprooting as many as 200 million people. But the author, former World Bank chief economist Nicholas Stern, said if action is taken now the benefits of determined worldwide steps to tackle global warming will massively outweigh the economic and human costs. "This is the most important report on the future published by this government in it's time in office. Some will always make a case for doubt in an issue such as this. Partly because it's implications are so frightening but what is not in doubt is that the scientific evidence of global warming caused by greenhouse gas emissions is overwhelming. It is not in doubt that if the science is right the consequences for our planet are literally disastrous and this disaster is not set to happen in some science fiction future many years ahead, but in our lifetime," British Prime Minister Tony Blair said at the launch of the report. "We know climate change is happening, we know the consequences for our planet. We now know urgent action will prevent catastrophe and investment in preventing it now will pay us back many times in the future," Blair added. Britain is pushing for a post-Kyoto framework that would include the United States -- the world's biggest producer of greenhouse gases that cause climate change -- as well as major developing countries such as China and India. President George W. Bush pulled the United States out of the Kyoto Protocol -- which obliges 35 rich nations to cut carbon emissions from burning fossil fuels in power plants, factories and cars -- in part because he said it hit jobs. Stern's report estimates that stabilising greenhouse gases in the atmosphere will cost about 1 percent of annual global output by 2050. Inaction, however, could cut global consumption per person by between 5 and 20 percent. The long-awaited report precedes U.N. climate talks, starting in Nairobi on Nov. 6, focusing on finding a successor to Kyoto, which ends in 2012. British finance minister Gordon Brown said harnessing the power of markets through a global carbon trading system was one of the best ways to curb the output of polluting gases. Sharing a platform with Blair and Stern, Brown proposed a new European Union target for emissions reductions of 30 percent by 2020 and 60 percent by 2050 and expansion of an existing carbon trading scheme to cover more than half of emissions. "Today I want to set a new ambition for Britain in future years, to lead the world in creating a stable and sustainable economy founded on low carbon. An economy that is both pro growth and pro green," Brown said. Brown wants the EU scheme, which sets overall limits for carbon emissions but then allows businesses to trade their quotas, to be linked with Australia, California, Japan, Norway and Switzerland so as to set a global carbon price that fixes a clear cost for pollution. Brown said the government would underline its commitment to tackling climate change by launching a new bill to enshrine its goal of cutting carbon dioxide emissions by 60 percent by 2050. He also said former U.S. Vice President Al Gore, who created a stir this year with his climate change documentary An Inconvenient Truth, would become one of his environmental advisers. In a questions and answers session British Prime Minister Tony Blair said other countries would have to get involved. "We have got to ensure that there is a framework that America will come into and China and India because the reality of this is unless you get those three actors in this framework it isn't going to succeed." Stern said that, on current trends, average global temperatures will rise by 2-3 degrees Celsius within the next 50 years or so, compared with temperatures in 1750-1850. "(This report) is about creating carbon markets, creating a price incentive to cut back on the carbon. It's about promoting R (Research ) and D (development), promoting energy efficency and above all it's international. It's getting countries to move together," Stern said The report also said that if emissions continued to grow, the earth could warm by several more degrees, with severe consequences. Poor countries would be worst hit as melting glaciers initially increase flood risk and then hurt water supplies, eventually threatening one sixth of the world's population.