Brown's pledges on climate change

Gordon Brown will insist that Britain must be a world leader in the fight against climate change - hinting that more ambitious reductions in greenhouse gas emissions may be necessary.

In his first major speech on the environment since becoming Prime Minister, he will underscore the need to act immediately to combat global warming and argue that green measures do not have to damage economic growth.

Despite recent reports he has been under pressure from ministers to curb commitments to reducing carbon emissions, Mr Brown will stress he is looking at the possibility of making them even tougher.

He is also expected to outline new ways of cutting emissions in the UK following the weekend publication of a major scientific report showing the Earth is heating up at a quickening pace because of human activity.

The United Nations' Intergovernmental Panel on Climate Change (IPCC) warned that current trends would see an temperature increases of up to 4 degrees centigrade and sea levels 60 cm higher by 2100.

Mr Brown will also cite International Energy Agency predictions of soaring energy demand.

He will argue that, rather than holding back growth in the UK, efforts to tackle climate change offer economic opportunities in the development of new low carbon technology.

It is possible to be both pro-environment and pro-growth, he will say.

His speech comes ahead of a major UN conference in Bali next month when countries will work on a successor agreement to the Kyoto Protocol.

Mr Brown's call for the most developed countries to take a lead on reducing carbon emissions will be seen as a message to the US, which famously shunned Kyoto, that it needs to be on board.