Rich countries owe poor a huge environmental debt

Zambia floods Jan 2008
Photograph: EPA




Using data from the World Bank and the UN's Millennium Ecosystem Assessment, 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 calculated the costs of consumption in low, medium and high income countries, both within their borders and outside, from 1961 to 2000. The team used UN definitions for countries in different income categories. Low income countries included Pakistan, Nigeria and Vietnam, and middle income nations included Brazil and China. Rich countries in the study included the UK, US and Japan.

Striking disparities

The magnitude of effects outside the home country was different for each category of consumption. For example, deforestation and agricultural intensification primarily affect the host country, while the impacts from climate change and ozone depletion show up the disparity between rich and poor most strikingly.

Greenhouse emissions from low-income countries have imposed $740 billion of damage on rich countries, while in return rich countries have imposed $2.3 trillion of damage. This damage includes, for example, flooding from more severe storms as a result of climate change.

Likewise, CFC emissions from rich countries have inflicted between $25 billion and £57 billion of damage to the poorest countries. Increased ultraviolet levels from the ozone hole have led to higher healthcare costs from skin cancer and eye problems. The converse figure is between $0.58 and $1.3 billion.

The team publish their results today in Proceedings of the National Academy of Sciences.

"We know already that climate change is a huge injustice inflicted on the poor," said Dr Neil Adger at the Tyndall Centre for Climate Change Research in Norwich, who was not involved in the research, "This paper is actually the first systematic quantification to produce a map of that ecological debt. Not only for climate change but also for these other areas."

"This is an accounting tool that allows you to say how much the high-income world owes the low-income world for the environmental externalities we impose on them," he said.

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. That meant leaving out damage from excessive freshwater withdrawals, destruction of coral reefs, biodiversity loss, invasive species and war. So the researchers believe the figures represent a minimum estimate of the true cost.
