These include severe water shortages that will get steadily worse, reduced agricultural productivity through the loss of topsoil, and unwanted growth of vegetation along sea-coasts and of algae at sea, caused by the heavy application of fertilisers.

The BBC's Margaret Gilmore: "Ignoring the problem is no longer an option"

The report recommends that the developed world must cut its use of natural resources by 90% to give the rest of the world a chance of emerging from poverty.

But the destruction of tropical rainforests has already gone too far to prevent irreversible damage and it is too late to regain the planet's former bio-diversity, the report finds.

US concerns and causes

Philippa Thomas travelling with President Clinton: "Work is crucial"

Raising temperatures here could increase malaria in Africa

"Unless we change course, most scientists believe the seas will rise so high they will swallow whole islands and coastal areas," Mr Clinton warned.

"Diseases like malaria will be borne by mosquitoes to higher and higher altitudes and across borders, threatening more lives, a phenomenon we already see today in Africa."

He called on people to realise that it is no longer necessary to burn up the atmosphere to build economies on oil and coal to create economic opportunity.

But the president had to acknowledge that his country was the main offender, producing more greenhouse gases than any other country in the world.

Small victories

Marion Cheatle, Report author: "We can all play a major role"

However, despite international agreement on the need to reduce the production of greenhouse gases, the report considers further disruptive climate change inevitable.