Climate change could have a devastating impact on Africa, wiping out all the benefits from the measures to help the continent agreed by the world's richest nations last year.
The warning will be issued by the British Government today when it announces plans to bring poor countries into the next round of international discussions to combat global warming.
The serious threat posed to the developing world will be highlighted when Hilary Benn, the Secretary of State for International Development, publishes his first White Paper setting out his department's strategy. It will warn that people in poor nations, while producing much lower carbon emissions than rich countries, could be the biggest victims of climate change.
They will have to cope with more droughts, more extreme temperatures and sudden and intense rainfall causing greater food insecurity, loss of income, higher death rates and more diseases. Research by the department to assess the impact on Africa by 2050, taking account of poverty forecasts, suggests that southern Africa and the Sahel, the Great Lakes areas and the coastal zones of eastern and western Africa will be particularly at risk.
In some parts of east Africa, higher rainfall and and temperatures will help crop production in the short term but there will be more frequent crop failures in the future. "What is clear is that Africa appears to have some of the greatest burdens of climate change impacts, certainly from the human health and agricultural perspective," the research concluded.
"It is a region with a generally limited ability to cope and adapt; and it has some of the lowest per capita emissions of the greenhouse gases that contribute to global warming. The likely impacts of climate change therefore present a global ethical challenge as well as a development and scientific challenge."
Mr Benn will pledge that British ministers and officials will help developing nations address climate change. He will signal a shift under which, instead of relying on help from rich nations on dealing with the consequences, governments from poor countries play a key role in formulating the world's response to the issue. That would mean developing countries joining talks on a new international agreement on the threat to the planet, called "Kyoto 2".
Mr Benn does not want the world to impose carbon emissions targets on poor countries, which they would be reluctant to accept, but wants them to form part of a new global consensus on the issue. In the long run, that could allow them to "sell" carbon emissions permits to raise money for their own development.
Mr Benn said yesterday: "Climate change is happening faster than any of us anticipated even five years ago. It is the most pressing global challenge of all, yet does not have a global framework for solving it. Climate Change knows no boundaries and neither should we."
Gordon Conway, the chief scientific adviser at the Department for International Development, said: "It is a phenomenon that occurs in a world that is already severely challenged. This is especially true of Africa where the existence of widespread poverty, hunger and poor health already affect millions of people. All prognostications suggest climate change will make their lives even worse."
Tony Blair said he hoped Africa and climate change would be discussed by G8 leaders at their summit in St Petersburg this weekend. But there is little sign of major progress at a meeting likely to be dominated by energy supplies. Jacques Chirac, the French President, criticised the US for blocking progress on climate change. He said: "Global threats require global responses. We shall not solve the problem of global warming if we each go our own way or increase the number of unilateral or partial solutions. This is particularly true for global warming. I am concerned at the weakening of the international regime for climate change. We must reverse this trend."
President Chirac said the seven G8 members party to the Kyoto protocol snubbed by America, should set an example by respecting their commitments, as Europe and France were doing. "It is up to them to show the way forward for the post-2012 period," he said. "We seek an ambitious agreement commensurate with the threat posed to humanity, one committing all the G8 countries, including the United States, as well as emerging countries."Reuse content