Depletion and Conservation of Natural Resources - The Economic Value Of The World's Ecosystems—how Much Is Nature Worth?

Nature performs valuable, practical, measurable functions, without which the human economy could not exist. Many experts contend that, as human activity gradually consumes or destroys this natural capital, the monetary value of the ecosystem to the economy must be calculated and considered. Thirteen economists, ecologists, and geographers studied 16 different biomes (ecological areas such as lakes, urban areas, and grasslands) to estimate the economic value of 17 ecosystem services. To do this they assigned dollar values to services performed by nature that are considered necessary to the human economy. Their report, published in the journal Nature (May 1997), estimated that ecosystems perform at least $33 trillion worth of services annually. Marine systems contribute about 63 percent of the value, mainly from coastal systems ($10.6 trillion). Terrestrial systems account for 37 percent of the value, mainly from forests ($4.7 trillion) and wetlands ($4.9 trillion). This total was 1.8 times the 1997 global gross national product of approximately $18 trillion. In other words the services performed by nature were 180 percent as valuable as all of humankind's economic activities.

Most experts, including the authors of the study, recognize the figure is a crude, conservative, "starting point" for an estimate of what the environment does for humans. Others contend nature's value is incalculable. Virtually everyone agrees that without nature's ecological contribution, human life could not exist. Furthermore, as ecosystems become more stressed and scarce in the future, their value will increase. If significant, irreversible thresholds are passed, the valuable services of these ecosystems may become irreplaceable.