Environmental Engineering Reference
In-Depth Information
governmental Panel on Climate Change (IPCC) appraised published
studies of biological systems. Of 59 plants, 47 invertebrates, 29 amphib-
ians and reptiles, 388 birds, and 10 mammal species, approximately 80
percent showed changes in the biological parameters measured, including
start and end of breeding season, shifts in migration patterns, shifts in
plant and animal distributions to higher elevations and toward the poles,
and changes in body size and population numbers.
4
Living creatures are
adaptable. The biological modifi cations the IPCC found are consistent
with global warming predictions.
The fate of plants in a warming world concerns botanists, but their
worries are likely unnecessary. Biologists from University Centre in Sval-
bard, Norway, studied the DNA of plants on the island. They found that
over the past 10,000 years, different species of plants have had little
trouble making the hop from the Norwegian mainland to the island 600
miles away. Plants are more adaptable to changing their habitable ranges
than we might think. Those in the business community may justifi ably
be concerned as the things in the natural world that they depend on
change locations as the climate changes, but for those interested only in
the survival of life forms on planet Earth, there is nothing to worry
about.
Climate change can have adverse or benefi cial effects on species. For
example, climate change could benefi t certain plant or insect species by
increasing their ranges. The resulting impacts, however, could be positive
or negative depending on whether these species were invasive and unde-
sirable (e.g., weeds, crop pests, tree-killing beetles, ticks, or mosquitoes)
or valuable to humans (e.g., food crops, enemies of crop pests, or pol-
linating insects).
The observed changes are compelling examples of how rising tem-
peratures can affect the natural world and raise questions of how the
most vulnerable populations will adapt to future increases in tempera-
tures and other climatic changes. For example, many fi sh species have
begun moving into now-warmer arctic waters. Between 1982 and 2006,
pollack moved their northward extent 30 miles northward; halibut 35
miles; rock sole 48 miles; and snow crab 55 miles.
5
The risk of extinction
could increase for some species, especially those that are already endan-
gered or at risk due to isolation by geography or human development,
low population numbers, or a narrow temperature tolerance range. The
IPCC estimates that 20 to 30 percent of plant and animal species are at
increasing risk of extinction if the global average temperature increases
by another 2.2 to 4.0 degrees.
