A major climate change summit brought together leaders from the world's 20 top polluting countries in Mexico to tackle the crisis as part of the G8 Gleneagles Dialogue. As the summit wrapped up yesterday, Tearfund has called for more urgency to address the problem.

The Christian relief and development agency expressed its "relief" today that the world's top 20 polluting countries finally agreed at the summit that the climate change problem was undeniable.

It added stressed, however, that much more needed to be done: "This is a modest step only. For most of the rest of the planet, the fact of climate change is common-knowledge. And until consensus over the science is matched with more ambitious targets and policy measures to tackle climate change, there will be little positive progress, particularly for the poorest people of the world."

As the country representatives gathered in Mexico, Tearfund warned that thousands of lives, as well as tens of billions of dollars in development work, would be lost in poor countries if more urgent action was not taken now.

Tearfund Advocacy Director, Andy Atkins stressed that international progress on climate change is too slow.

"Poor communities where Tearfund's partners work have been living with the impact of climate change for several decades - erratic rains, increasing numbers of disasters, floods and droughts. These poor communities, who have contributed least to climate change, are suffering the most from its effects. Current efforts to respond to climate change are simply not urgent enough."

Britain hailed the talks a success, saying they brought together developed and developing nations.

G8 members were joined by politicians from China, India, Brazil, Mexico, South Africa, Indonesia and other growing nations as they heard from experts on climate science, economics, technology, business and policy.

The findings of a UK-commissioned study on the economics of climate change were presented at the climate change summit by economist and study author Nicolas Stern. The review advocated urgent action now to tackle global warming as soon as possible and said that the costs of such action were manageable.

"The emerging evidence is clear," says Rachel Roach, Tearfund's climate change policy advisor. "If we don't act now to tackle climate change, we will pay economically a lot more later. Now governments have accepted the reality of climate change, they must put money into mitigating against it and helping countries already living with its effects."

Tadesse Dadi, a Tearfund worker in Ethiopia said climate change debates always sounded like the problem was in the future, yet millions were already being affected: "Climate change may not yet be a problem for people in Europe, but here in Ethiopia its effects are being felt today by millions of ordinary men and women farmers. Aside from the awful drought that devastated parts of Somalia, southern Ethiopia and northern Kenya, the impact of climate change is being faced every single year by peasant farmers in different parts of our country."

In Tearfund's submissions to the Gleneagles process and the Stern Review it stressed the need for countries to now agree measures that will keep global temperature rises below 2 degrees above pre-industrial levels.

The development agency also recommended "new thinking" on development that would incorporate the growing reality of climate change and also take into consideration the fact that it is already undermining wider efforts to halve global poverty by 2015 through the Millennium Development Goals.

Andy Atkins concluded: "The British Government and the international community must redouble their efforts to mitigate climate change by reducing carbon emissions internationally, while also making funds available to help those hardest hit by the climate change crisis on their doorstep."