LONDON - Climate change could spawn a new era of conflicts around the world over water and other scarce resources unless more is done to curb greenhouse gas emissions, the foreign secretary, Margaret Beckett, warned yesterday.

She said climate-driven conflicts were already under way in Africa. Underlying the Darfur crisis, she said, was a "struggle between nomadic and pastoral communities for resources made more scarce through a changing climate".

Speaking at the Royal United Services Institute in London, Mrs Beckett quoted evidence that a similar conflict was brewing in Ghana where Fulani cattle herdsmen are reportedly arming themselves to take on local farmers in a confrontation over water and land as climate change expands the Sahara desert. The foreign secretary said the Middle East - with 5% of the world's population but only 1% of its water - would be particularly badly affected, with Saudi Arabia, Iran and Iraq particularly hard hit by a drop in rainfall.

She said the Nile could lose 80% of its flow into Egypt, a country which would also be threatened by rising sea levels in the Nile delta, its agricultural heartland, where flooding could displace 2 million people, threatening internal stability.

"Resource-based conflicts are not new. But in climate change we have a new and potentially disastrous dynamic."

Her speech echoed a similar warning from the European commission in January that global warming could trigger regional conflicts, poverty, famine, mass migration and the spread of infectious diseases such as malaria and dengue fever.

The British government has this year attempted to focus global attention on climate change as a security threat, and Mrs Beckett used British chairmanship of the UN security council in April to convene the council's first debate on the issue.

"It requires a whole new approach to how we analyse and act on security," Mrs Beckett said. "The threat to our climate security comes not from outside but from within: we are all our own enemies."

She compared the struggle to contain climate change to the cold war, which also had to be fought on diplomatic, economic, political and cultural fronts. She said public and private sectors would have to cooperate to ensure the bulk of investment in the energy sector by 2030 was spent on low carbon and energy efficient options.

Britain has pledged to cut carbon emissions by 30% by that year, but the realism of that goal with current policies has been called into question by climate experts.

This week scientists, diplomats and activists met in Bonn to start formulating a successor to the Kyoto Protocol on global warming, which expires in 2012.

Meanwhile at the UN, a vote is due today on whether Zimbabwe will take over the chair of the Commission on Sustainable Development (CSD), which oversees environmental issues in the developing world. The US, the UK and other European nations have objected to Zimbabwe's candidacy on the grounds of its human rights records and the parlous state of its economy, with an inflation rate of over 2,000%. But it is the turn of African states to nominate a country to chair the commission and they will vote today on whether to confirm Zimbabwe.

A European official said: "It makes no sense to make a minister from Zimbabwe head of a commission that affects millions of people, when the people of his own country have been suffering for so long from economic mismanagement."

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