Conservation group the World Wide Fund for Nature says in its regular Living Planet Report that humans currently consume 20 per cent more natural resources than the earth can produce.

“We are spending nature’s capital faster than it can regenerate,” said WWF chief Claude Martin, launching the 40-page study.

“We are running up an ecological debt which we won’t be able to pay off unless governments restore the balance between our consumption of natural resources and the earth’s ability to renew them.”

The conservation group says humanity’s reliance on fossil fuels, the spread of cities, the destruction of natural habitats for farmland and the exploitation of the oceans are outstripping the planet’s capacity to cope.

The biggest culprits are residents of Australia, the United Arab Emirates, the United States, Kuwait and Sweden, who leave the biggest ecological footprint.

Most of a person’s footprint is caused by the space needed to absorb the waste from energy consumption, including carbon dioxide.

Burning fossil fuels in power plants and automobiles releases carbon dioxide, which experts say contributes to global warming. The planet is unable to keep pace and absorb the emissions..

The fund also points to an alarming drop in natural species. Populations of land, freshwater and marine species fell on average by 40 per cent between 1970 and 2000.

The report cites urbanisation, forest clearance, pollution, overfishing and the introduction by humans of non-native animals as major causes.

The impact of an average North American is double that of a European, but seven times that of the average Asian or African.

Residents of the United Arab Emirates, who use air conditioning extensively, leave a 9.9-hectare footprint, two-thirds caused by fossil fuel use. The average US resident leaves a 9.5-hectare footprint, also largely from fuel.

Swedes leave a 7-hectare footprint, but most is caused by land use. Like its Nordic neighbours, the country has won praise from campaigners for cutting fossil fuel use.

The study also warned of increasing pressure on the planet’s resources amid spiralling consumption in Asia.