It now also appears that tropical forests are responding to higher levels of CO 2 in the atmosphere by sequestering more carbon. If natural forest escapes destruction, it prevents an increase in CO 2 . So from a biological diversity perspective it would be very desirable for natural forests to be included in the Clean Development Mechanism under the Climate Convention, which would allow payment for this ecological service. Costa Rica already has Certifiable Tradable Offsets ready for sale. There are of course technical and complex issues to be resolved about what would qualify and how credit should be given, but trees and forests nonetheless represent an easy way to start addressing the CO 2 problem.
Climate change is likely to have a devastating effect on biological diversity.
So carbon offset income for natural forests is probably the single most important measure which can be taken for biological diversity because it conserves it directly and reduces greenhouse gases at the same time. Deforestation clearly played a role in aggravating the devastating floods associated with Hurricane Mitch and the ghastly Venezuelan floods and mudslides last December. Both were only partially 'natural disasters', ones that will doubtless be visited on other countries with similarly bare hillsides. Quite apart from humane considerations, you do not need a Nobel Prize to conclude that it is better economically to stabilize slopes with forests than to suffer disasters like these. Then, of course, there is the service that forests provide in supplying reliable flows of clean water.