The environmental damage caused to developing nations by the world's richest countries amounts to more than the entire third world debt of $1.8 trillion, according to the first systematic global analysis of the ecological damage imposed by rich countries. There are huge disparities in the ecological footprint inflicted by rich and poor countries on the rest of the world because of differences in consumption. The authors say that the west's high living standards are maintained in part through the huge unrecognised ecological debts it has built up with developing countries. At least to some extent, the rich nations have developed at the expense of the poor and, in effect, there is a debt to the poor," said Prof Richard Norgaard, an ecological economist at the University of California, Berkeley, who led the study. "That, perhaps, is one reason that they are poor. You don't see it until you do the kind of accounting that we do here." The researchers examined so-called "environmental externalities" or costs that are not included in the prices paid for goods but which cover ecological damage linked to their consumption. They focused on six areas: greenhouse gas emissions, ozone layer depletion, agriculture, deforestation, overfishing and converting mangrove swamps into shrimp farms. The team confined its calculations to areas in which the costs of environmental damage, for example in terms of lost services from ecosystems, are well understood. "We think the measured impact is conservative. And given that it's conservative, the numbers are very striking," said co-author Dr Thara Srinivasan, who is also at Berkeley.

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