Arriving in Copenhagen, Mr Brown said: "Over the next three days the leaders of almost every nation on earth will gather in Copenhagen. Their role; their opportunity; their responsibility: to shape the future of humanity. It is a defining moment." To win around developing nations who are resisting limits on their carbon emissions, Mr Brown could back a deal for rich countries to give more money. He is now preparing to make Britain pay into another international fund to help poor countries limit the amount of their forests they cut down for logging and agriculture. Increasing Britian’s “green” spending is controversial because of the size of the Government’s deficit. As he arrived in Copenhagen, Mr Brown, painted an apocalyptic picture of the consequences of failure at the summit, saying that the world economy would suffer an unprecedented “catastrophe” if temperatures rise too far.