5.4.3.3.4. Decomposers and soil maintainers
Invertebrates and microorganisms living on or below the soil surface provide
needed goods and services to human societies (e.g., mixing and aeration of soils,
decomposition of materials and human waste) (Daily et al., 1997). These processes
contribute to creation of fertile topsoil from organic matter and mineral components
of the soil. Some of these organisms (e.g., ants) are susceptible to climatic
changes, especially droughts (Folgarait, 1998). On a global scale, the estimated
cost of replacing waste elimination services performed by these organisms is
hundreds of billions of U.S. dollars annually; the estimated cost of replacing
topsoil production services is tens of billions of U.S. dollars annually (de
Groot, 1992; Crosson et al., 1995; Pimentel et al., 1995; Daily et al., 1997).
5.4.3.3.5. Protection of endangered species
Another way of assessing the value of wildlife is by examining how much is
spent on its conservation. In fiscal year 1995, approximately US$330 million
was spent on the conservation of threatened and endangered species in the United
States and its territories (U.S. Fish and Wildlife Service, 1995). As pressures
facing wildlife increase, the number of species that require conservation attention
also will most likely increase.
5.4.3.3.6. Subsistence hunting
People in many parts of the world depend on wildlife for their daily nutritional
needs. This is most pronounced in less-developed areas. For example, the Cree
along James Bay in Canada harvest approximately 800,000 kg of animal food annually.
The per capita replacement value of this harvest was estimated to be CDN$6,000
in 1986 dollars (Scott, 1987). The abundance of caribou (Rangifer tarandus groenlandicus)
available for harvest by indigenous peoples could decrease as a result of increased
temperatures, snowfall, and potential shifts in the timing of precipitation
(Brotton and Wall, 1997; Ferguson, 1999). Adverse impacts also have been projected
for other subsistence species, including marine birds, seals, polar bears (Stirling,
1997), tundra birds (Jefferies et al., 1992), and other tundra-grazing ungulates
(Jeffries, et al., 1992; Gunn, 1995).
Wildlife species also are a significant source of food and medicine for people
in many temperate and tropical countries, such as Botswana and Nigeria (McNeely
et al., 1990) and Australia (Bomford and Caughley, 1996). Among the Boran (Kenya),
birds are used for medicines (ostrich oils) and their feathers for cleaning
wounds (Isack, 1987). In many countries, climate change impacts such as reductions
in wildlife populations may have the greatest impact on the lowest-income groups—those
with the least ability to adapt if hunting opportunities decline (Arntzen and
Ringrose, 1996).
5.4.3.3.7. Recreational use of animals and ecotourism
In many African countries, ecotourism to view wildlife is a major contributor
to gross national product (GNP). Worldwide, ecotourism is estimated to provide
US$500 billion to 1 trillion annually to the global economy (Munasinghe and
McNeely, 1994). Changes in climate could reduce the populations of some of the
species people are willing to pay to see (Mills et al., 1995; Allen-Diaz, 1996).
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