5.4.5. Equity Issues
People in many parts of the world are dependent on wildlife for all or part
of their daily nutritional needs. A typical adaptive response to this situation
would be to replace all or part of this food with store-bought products. This
might be feasible in areas near developed societies but could become increasingly
difficult in more remote communities. However, there is more to subsistence
hunting than the capture of food. Subsistence hunting plays a major role in
the culture of Cree communities in northern Canada. "The killing, preparation,
sharing, and consumption of game is central to the seasonal renewal of social
relations in Cree villages, and of a relationship to the land which is both
secular and sacred in importance" (Scott, 1987). Even if compensations
or substitutions for subsistence uses could be made, there still would be equity
issues stemming from the loss of culture associated with this way of life.
Many of the aforementioned potential adaptations are more applicable to developed
countries than in developing countries. For example, the use of leased honeybees
is not applicable to crops fertilized by flying foxes or other wild animals.
The same can be said of many forms of seed dispersal. Increased use of pesticides
may require more capital than is available to small farmers in some developing
countries (Pimentel et al., 1992). Adaptations that may be practical for developed
countries simply may not be equitable for developing countries.
5.4.6. Vulnerabilities, Sensitivities, Uncertainties
In trying to understand and predict potential impacts of climate change on
wildlife species, some species and geographic areas are found to be at greater
risk than others. Species with small populations, restricted ranges, and specific
habitat requirements often are most vulnerable (see Section
Migratory species may be especially vulnerable because they require separate
breeding, wintering, and migration habitats. In many cases, one or more of these
habitats could be at risk because of climate change and other habitat loss.
For example, a large portion of the eastern population of the monarch butterfly
(Danaus plexippus) winters in a small region of warm-temperate dry forest in
Mexico. With climate change, this area is projected to contain trees that are
more typical of a subtropical dry forestprobably unsuitable for wintering
monarchs (Villers-Ruíz and Trejo-Vázquez, 1998). The relative
vulnerability of shorebird migration sites in the United States varies, depending
on local geomorphologic and anthropogenic factors, and these factors could exacerbate
the effects of sea-level rise. For example, southern San Francisco Bay could
lose most of its intertidal feeding habitat with a 2°C average temperature
rise (medium confidence) (Galbraith et al., 2001).
One key region of concern is the Arctic and Antarctic, where the temperature
increase is projected to be large and changes to habitat availability and accessibility
(e.g., freezing and thawing of sea ice and tundra) are expected. Such changes
may hamper migration, reproduction, and survival of many species, including
birds, polar bears (Ursus maritimus), caribou, and musk-oxen (Jefferies et al.,
1992; Stirling and Derocher, 1993; Gunn and Skogland, 1997; Stirling, 1997).
Many biological uncertainties exist in the understanding of ecosystem processes.
Nevertheless, the balance of evidence suggests that projecting impacts of climatic
change on a variety of wildlife species is possible (medium confidence). Laboratory
and field studies have demonstrated that climate plays a strong role in limiting
species' ranges (high confidence). Only a small fraction of all species have
been monitored long enough to detect significant trends. Most monitored species
that show significant trends have exhibited changes over the past few decades
that are consistent with local warming and expected physiological responses
(high confidence). However, potential specific changes in wildlife resulting
from climate change can be projected only with low confidence for most species
because of many possible contributing factors, such as habitat destruction and
exotic invasive species. Some species clearly are responding to global change
(see Section 5.4.3), and many more changes probably have
gone undetected. Researchers are in the process of coupling these discernible
changes with various biological theories regarding climate and species spatial
and temporal patterns; through this process, we expect that reliable general
projections can be and in fact are being made (high confidence).
Scientists also need to develop a better understanding of how all of the components
of ecosystems work together. The role each species plays in ecosystem services,
in wild and managed systems, is necessary to understand risks and possible surprises
associated with species loss. Without this information, the probability of surprises
associated with species loss is high (medium confidence).