Pastoralist communities like the Maasai could offer insights into coping with climate change in East Africa, but their political marginalisation means valuable knowledge is not being used, aid agency Oxfam said.

Skills learned over generations roaming with their herds across the hot deserts, lush green savannahs and rocky scrublands of Kenya, Uganda and Tanzania could be of huge value on a continent forecast to be hit hard by global warming.

But leaders in the region have largely sidelined and ignored them, sneering at their way of life as outdated and irrelevant.

"All too often the direct economic value generated by pastoralists is not retained in their communities, and the indirect value is unrewarded and even unacknowledged by decision-makers," Paul Smith-Lomas, regional director for Oxfam International, said in a statement.

A new Oxfam report, Survival of the Fittest, describes years of marginalisation and inappropriate development policies coupled with increased competition for resources that has hit some pastoralists' ability to maintain a sustainable livelihood.

Oxfam said east African governments had mostly excluded such communities - who often inhabit remote parts of their territories - from national political processes, tending to view them as minority vote that was not worth winning.

But slowly, Oxfam said, some were realising their value.

Pastoralists have been adapting to climate changes for millennia, and that should help them cope with the warming forecast for Africa, said Mohamed Elmi, who was named in April as Kenya's first minister for the north and other arid lands.

"However, their adaptability cannot be realised without government support and investment," he said.

Scientists warn that Africa will be hit hard by global warming, with the UN climate panel predicting a temperature rise of up to between two and four Celsius by the 2080s.

It forecasts more droughts, storms, floods and rising seas, as well as changing ranges for diseases. Tens of millions of people across the continent face food and water shortages.

Oxfam called on governments and development agencies to overhaul their policies towards pastoralists, who have long used traditional livestock and land-management strategies to manage drought and flood cycles.

Social welfare systems should be put in place, it said, so they can continue to pass on the lessons of their traditional lifestyle, or choose an alternative way of making a living.

"Communities must be at the heart of efforts to build their resilience to climate change because adaptation is inherently local," Mr Smith-Lomas said.

"It will only work if local people are leading the process."