Some say the question is unanswerable, that it is impossible to calculate a dollar value for the natural world. But economists and ecologists are searching for the answer anyway. And they say it is time that the value of these functions is considered when economic decisions are made. One notable example of nature's economic value that they cite is the purification of New York City's water supply by microorganisms as the water percolates through the soil of the Catskills.
Nature performs a long list of other economic services as well.
Flood control, soil formation, pollination, food and timber production, provision of the raw material for new medicines, recreational opportunities and the maintenance of a favorable climate are among them. And to the extent ecosystem services are noticed at all, people have tended to regard them as free. Now, as human activity gradually uses up or destroys this natural capital and eats away at the natural systems that provide many of the services, many experts are insisting that the worth of ecosystem services must be calculated and heeded. The results of the latest and in some ways the most ambitious effort to place a dollar value on natural capital and services were announced last week. Most of this, they said, lies outside formal markets and is therefore not reflected in market prices, the customary gauge of economic value.