London - The world is heading for an "ecological credit crunch" with demands on natural resources exceeding by almost a third what the earth can sustain, conservation groups in Britain have warned.

The Living Planet Report, produced by the World Wildlife Fund (WWF), Britain's Zoological Society and the Global Footprint Network said that more than 75 per cent of the global population lived in countries where consumption levels were outstripping environmental renewal.

This fact made those countries "ecological debtors," meaning that they are drawing - and often overdrawing - on the agricultural land, forests, seas and resources of other countries to sustain them, said the report published Wednesday.

The report concludes that the reckless consumption of "natural capital" was endangering the world's future prosperity, with clear economic impacts including high costs for food, water and energy.

"If our demands on the planet continue to increase at the same rate, by the mid-2030s we would need the equivalent of two planets to maintain our lifestyles," WWF International director-general James Leape said in the report.

The countries with the biggest impact on the planet are the US and China, which together account for some 40 per cent of the global footprint, the report showed.

It said that the US and United Arab Emirates have the largest ecological footprint per person, while Malawi and Afghanistan have the smallest.

According to the WWF, Britain's national ecological footprint - the impact of consumption on nature - was the same in volume as that of 33 African countries put together.

"We are increasingly overdrawing on the natural resources which underpin all life on Earth, and our human footprint - the impact we have - is 30 per cent bigger than the planet's ability to regenerate," said Chief Emeka Anyaoku, the WWF's international president.

"Devastating though the financial credit crunch has been it's nothing as compared to the ecological recession that we are facing," he warned.

The more than 2 trillion dollars lost on stocks and shares was "dwarfed" by the up to 4.5 trillion dollars worth of resources destroyed forever each year, said Anyaoku. (dpa)