Climate protesters on long walk

The group want a new global agreement on climate change

Walkers have set off on a 995 miles (1,600km) around the UK to try to draw attention to climate change.

The Christian Aid event aims to get signatories for a petition calling for Britain to negotiate a new global agreement to curb climate change.

The charity's Paul Brannen said: "Climate change is the most serious threat to humanity."

Some 50,000 people are expected to join the group of 18 walkers along the route over 11 weeks.

It's about time we took action to save our planet Mohammed Adow

The marchers who come from a wide range of countries affected by climate change, including India and Brazil, will speak about the impact of rising temperatures on their homelands.

Mohammed Adow from Kenya will be walking all the way to London.

"We want to show the people of the UK, their government, their politicians, their companies, that climate change is real and it's happening," he said.

"And it's about time we took action to save our planet.

"If you don't hear this message then we will be talking about disaster in the very near future."

The group want Gordon Brown to negotiate a new global agreement at a United Nations meeting in Bali in December.

Christian Aid says people in the least-developed countries are already dying of floods, droughts and conflict over already scarce resources.

Head of campaigns for Christian Aid, Paul Brannen, said: "We want to get the message out... that we need to act now to improve the Climate Change bill so that the people of the developing world, who've done the least to cause the problem of climate change, aren't going to suffer worse in the future."

He added they needed the UK's help by reducing emissions and by "putting pressure on the UK government to pursue climate-friendly national and international policies".

The walkers will take in 70 towns and cities on their route.