“Barring an unexpected decline in human numbers from current levels, biodiversity will not reverse its downward trend, air and water pollution will not reverse their increasing trends,(all according to World Resources Institute data) and the WHO will not report a decrease in the percentage of humans with persistent illnesses.”

The majority of living (at the time) Nobel winners in science signed a "Warning to Humanity" concerning the overshoot of human activity within a finite habitat.
The Union of Concerned Scientists website currently refers to it:
http://www.ucsusa.org/publication.cfm?publicationID=240
full Warning:
http://dieoff.org/page8.htm
There are many other eminent scientists agreeing such as E.O. Wilson ("The Bottleneck") Techno-optimists and cornucopian theorists are the potential counterparties to this bet.

From WRI Trends:


Third, threats to biodiversity from all sources are quickly reaching a critical level that may precipitate widespread changes in the number and distribution of species, as well as the functioning of ecosystems. Current extinction rates are 100 to 1,000 times higher than prehuman levels, and projected losses of habitat from land conversion, as well as increasing competition from nonnative species, will probably push this rate higher still.

Even as these trends indicate the environmental challenges ahead, it is important to remember that they can be modified with human resolve. Already, the transition to more environmentally benign ways of growing food, producing goods and services, managing watersheds, and accommodating urban growth has begun in many far-sighted communities and companies. How fast this transition to more "sustainable" forms of production and environmental management will proceed, and whether it can effectively mitigate the effects of large-scale environmental change, is the real question.