Rich consumers are still voraciously gobbling up the world's resources, despite the worst recession in a generation, with their appetite pushing the planet into "ecological debt" from today , according to a report by think-tank the new economics foundation.

This "ecological debt day" marks the point in the year when consumption around the world exceeds the Earth's annual "biocapacity" — so for the remainder of the year, we will be eating into environmental resources that will not be replaced, according to nef's calculations.

Andrew Simms, nef's director, said the deep recession had delayed this "ecological debt day" by only 24 hours compared with last year, when it fell on 24 September. He warned that as G20 leaders gather in Pittsburgh to discuss global finance, there is a risk that the world economy will be kick-started again, without learning the lessons of the "consumption explosion".

"Debt-fuelled over-consumption not only brought the financial system to the edge of collapse, it is pushing many of our natural life support systems toward a precipice. Politicians tell us to get back to business as usual, but if we bankrupt critical ecosystems no amount of government spending will bring them back," he said.

In the UK, nef warns of increasing dependence on overseas energy, declining self-sufficiency in food, and the proliferation of "boomerang trade" — sending goods to foreign markets and receiving almost identical items back.

The research also underlines the yawning gap between the energy consumption of the world's poorest people, and the rich. Just 7% of the global population produces 50% of greenhouse gas emissions. A typical American will by 4am on January 2 have produced as many emissions as a Tanzanian generates in a year.

Nef argues that while the arrival of reliable electricity and other energy resources could bring enormous improvements in life expectancy and quality of life in developing countries, when consumption increases above a certain level, it will stop improving people's health or happiness.

Beyond this point, they say, "to increase human well-being, the focus should shift away from a quantitative focus on income and consumption, towards more qualitative improvements in the human environment to do with culture, civic, community and family life, long-term learning and those other dimensions that contribute to relatively long and happy lives."

The analysis suggests many countries have passed far beyond saturation point, into wasteful "overconsumption".

In the past 50 years, the report argues, people in the rich world have changed their lifestyles radically, and "in doing so, we have generally assumed that the resources and energy these activities rely on are limitless and cheap." In the 1970s, the average household in the UK had 17 domestic appliances, for example - but that had almost trebled, to 47, by 2006, and is expected to continue rising. Yet in fact, consumption has begun to gnaw away at natural resources at a rate which cannot be sustained.

Concern about the damage caused by the unrestrained pursuit of economic growth echoes a call by President Nicolas Sarkozy last week for politicians to look beyond GDP, to wider measures of the quality of life. Sarkozy published a report from Nobel prize-winning economists Joseph Stiglitz and Amartya Sen, advocating a broader approach to assessing the health of an economy.

These arguments have been given added urgency by the financial crisis, which undermined the arguments for unfettered consumption-fuelled growth.

"For years, we proclaimed the financial world a creator of wealth, until we learned one day that it had accumulated so much risk that it plunged us into chaos," Sarkozy said last week.

Simms calls for a radical redistribution between the millions of "underconsumers," in the poorest countries, whose lives could be transformed by small amounts of energy a year — and the bloated overconsumers in the rest of the world.

"We need a radically different approach to 'rich world' consumption. While billions in poorer countries subsist, we consume vastly more and yet with little or nothing to show for it in terms of greater life satisfaction. Defusing the consumption explosion will give us the chance of better lives," he said.