At the Earth summit in Rio, the thorny issue of how to value biodiversity was discussed, in order to help governments develop meaningful plans and policy associated with conserving biological diversity.

Assessments of the economic benefits of biological diversity have been based primarily on our ability to generate revenue from biodiversity through activities that produce measurable results such as pharmaceutical development and tourism. However, the economic value of ecosystem services, (such a water purification and reduction in soil erosion) is difficult to calculate and puts us in a potentially dangerous position. If we can't "value" the system does this imply that destruction is acceptable?

WHAT LIES AHEAD?

We can anticipate an ever-increasing competition among different uses of the available land, and the maintenance of biodiversity may not rank high in the face of other, more obvious demands. The population of the Earth will likely double by the year 2050 with the largest population, inhabiting tropical and subtropical Asia, Africa, and South America. These areas are the regions in greatest need of economic development, and the twin pressures of population growth and economic expansion can only increase the demands on biological resources.