Damage to forests, rivers, marine life and other aspects of nature could halve living standards for the world's poor, a major report is to conclude. Current rates of natural decline might reduce global GDP by about 7% by 2050.says a report about the Economics of Ecosystems and Biodiversity review (see also Biodiversity 'fundamental' to economics).
All very well, but be aware of the inadequacey measures such as GDP. Jonathan Rowe explains this well in testimony (pdf) to a U.S. Senate Committee in March of this year.
[A footnote to Rowe: The quantification of Ireland in the 1640s is not "the first known attempt in Western history to create a total inventory of a nation’s wealth." There is Domesday (1086), for one.]