Leaked versions of the report, published in Japan tomorrow, warn that rising global temperatures, droughts and heat waves will threaten food supplies and human health, while hundreds of millions of people will be affected by coastal flooding.

Climate change will cause economic losses, exacerbate poverty and increase migration and risks from violent conflict as well as causing damage to wildlife and habitats, the study by experts from around the world is expected to warn.

UN report warns of the devastating effects of global warming which could lead to WARS between nations and food shortages.

Amazing pictures from deep in the Amazon show startled tribesman shaking their spears at plane as they are pictured from the sky.

In Europe, heatwaves, droughts and heavy rainstorms will increase and there will be a greater risk of coastal and river flooding, it is expected to say, while heat-related deaths will also increase.

The report, which collates work by thousands of scientists from across the planet, is likely to state that global warming has already left its mark on all continents and oceans, and is expected to warn that even a small increase in temperatures could lead to irreversible changes.

Climate change is 'hugely threatening' to life both in the UK and globally, Mr Davey told The Observer, saying that not to lead the fight against it would be 'deeply irresponsible'.

Energy Secretary Ed Davey has also declared that Britain must spearhead the worldwide battle against global warming
The Lib Dem MP said: 'Climate change is impacting our way of life in the UK... The impacts on our people could be huge. We could see problems of real devastation from flooding and other severe weather events hitting food and water availability - really significant things.'

He added: 'Climate change is hugely threatening to our way of life, in the UK, Europe and the world. Not to lead is deeply irresponsible. If you don't lead, you will not bring others with you.'

Britain has made recent decisions that put the environmental agenda low on its list of priorities, scrapping green levies from energy bills and defeating efforts in Europe to set renewable energy targets for 2030 for each nation, the newspaper said.

But Mr Davey was adamant that climate change sceptics in the Government had been defeated, saying: 'Those of us who care about climate change and believe it is something we need to lead on have won the argument internally. People don't realise that we got a deal across the coalition that puts Britain right at the head, the most ambitious country.'
He added that Britain had agreed to slash emissions by 50 per cent by 2030 as part of a global deal.

Dr Williams, who stepped down as leader of the Anglican Church just over a year ago, said tomorrow's report puts 'our local problems into a deeply disturbing global context'.

Writing in his capacity as chairman of Christian Aid, he said: 'We have heard for years the predictions that the uncontrolled burning of fossil fuels will lead to an accelerated warming of the Earth.

'What is now happening indicates that these predictions are coming true; our actions have had consequences that are deeply threatening for many of the poorest communities in the world.

'Rich, industrialised countries, including our own, have unquestionably contributed most to atmospheric pollution. Both our present lifestyle and the industrial history of how we created such possibilities for ourselves have to bear the responsibility for pushing the environment in which we live towards crisis.'

Campaigners yesterday warned that the world faces a 'bleak future' without action to tackle climate change and leading environmentalists called on politicians to break the world's dependency on fossil fuels.
Friends of the Earth's executive director Andy Atkins said:

'We face a bleak future if the world continues to ignore the grim scientific warnings of our failure to tackle global warming.

'Droughts, floods and famines are just some of the devastating effects that people around the world are already suffering from more frequent extreme weather - and, unless we take urgent measure, it will get far worse.'

Sally Uren, chief executive of Forum for the Future, which advises businesses and governments on sustainability, said: 'The IPCC report should be read as a vital wake-up call.

'It is now more clear than ever that the risk to society from climate change is real and that large-scale action is needed now, by all of us, to both cut our carbon emissions, and also to accelerate the pace at which we adapt to a rapidly changing climate.'

Yesterday major landmarks in the UK and across the globe switched off their lights for 60 minutes to mark Earth Hour, the World Wildlife Fund campaign to raise environmental awareness.

Big Ben, the Houses of Parliament and Buckingham Palace all went dark, along with Edinburgh Castle, Brighton Pier, the Eiffel Tower and Sydney Opera House.

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