Environmental Services

Environmental services are processes and functions provided by the Earth's myriad environments and ecosystems that sustain the human condition. The characterization, definition, mapping, and economic valuation of environmental services (also commonly referred to as ecosystem services) constitute a very active research area at the dawn of the 21st century.

One example of these services includes the pollination of crops and nonagricultural plants by bees and other pollinating species. The disappearance or extinction of bees alone would represent the loss of a nonmarketed ecosystem service that would have profound and painful impacts on the human condition. Another example is the erosion control services provided to various extents by vegetation. This example demonstrates how there can be a spatial dependence of the value of various ecosystem services. For example, a fire can dramatically diminish the erosion control services of a forest. The economic value of these erosion control services can vary based on proximity to capital infrastructure (e.g., reservoirs), agriculture, and vulnerable populations. A highly generalized list of ecosystem services would have to include the various regulatory, production, and control functions that ecosystems provide (Table 1).

Table 1 Ecosystem services and ecosystem functions

Source: Adapted from Costanza, R., d'Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., et al. (1997). The value of the world's ecosystem services and natural capital. Nature, 387, 253–260.

The loss and/or degradation of various environmental services has the potential of inflicting significant social, financial, and environmental damage. Some of these damages will be market damages (negative impacts on gross domestic product [GDP]), and some are nonmarket damages (not accounted for in GDP). A clear example of a market damage that could be potentially attributed to a phenomenon such as global climate [Page 1001]change is the loss of tourism dollars associated with visits to coral reefs that are destroyed by sea-level rise and or sea temperature change. An example of nonmarket damage is the loss of the ecosystem service of storm protection provided by coastal wetlands in a sea-level-rise scenario. Perhaps ironically, the value of the storm protection services of coastal wetlands (on a per-hectare basis) actually goes up with climate change-induced increases in storm frequency and intensity. Traditional economic paradigms are increasingly challenged by environmental problems, and assessing the costs and benefits of changes to ecosystem services from a strictly economic perspective is particularly problematic.