London, May 30 : An environmental review, headed by an Indian, has concluded that damage to forests, rivers, marine life and other aspects of nature could halve living standards for the world's poor.
According to a BBC report, Pavan Sukhdev heads the review, referred to as The Economics of Ecosystems and Biodiversity (TEEB) review.
Sukhdev, a managing director in the global markets division at Deutsche Bank, was selected to lead the project by the German government and the European Commission during the German G8 presidency.
The document to be released at the Convention on Biological Diversity (CBD) meeting in Bonn, is an interim report into what the review team acknowledges are complex, difficult and under-researched issues.
"You come up with answers like 6% or 8% of global GDP when you think about the benefits of intact ecosystems, for example in controlling water, controlling floods and droughts, the flow of nutrients from forest to field," said Sukhdev.
"But then you realise that the major beneficiaries of nature are the billion and a half of the world's poor; these natural systems account for as much as 40%-50% of what we define as the 'GDP of the poor'," he told BBC News.
The 7% (approx.) figure that the review determines is largely based on loss of forests. The report will acknowledge that the costs of losing some ecosystems have barely been quantified.
The trends are understood well enough - a 50% shrinkage of wetlands over the past 100 years, a rate of species loss between 100 and 1,000 times the rate that would occur without 6.5 billion humans on the planet, a sharp decline in ocean fish stocks and one third of coral reefs damaged.
However, putting a monetary value on them is probably much more difficult, the team acknowledges, than putting a cost on climate change.
The report highlights some of the planet's ecologically damaged zones such as Haiti, where heavy deforestation - largely caused by the poor as they cut wood to sell for cash - means soil is washed away and the ground much less productive.
The review determines that ecosystem damage is likely to reduce food supplies in vulnerable areas. It also emphasized the importance of protected areas and of curbing deforestation.
An early draft of the TEEB review, seen by BBC News, has concluded that, "Lessons from the last 100 years demonstrate that mankind has usually acted too little and too late in the face of similar threats - asbestos, CFCs, acid rain, declining fisheries, BSE and - most recently - climate change".