Environmental Engineering Reference
In-Depth Information
This means that before we can achieve a true reduction in carbon dioxide levels, we have to first stabilize the
rate of the current emissions
increase.
The three gases specifically targeted for stabilization and then reduction
are carbon dioxide, methane, and nitrous oxide.
Since cars currently produce almost 30 percent of carbon dioxide emissions in the United States, increasing ef-
ficiency measured in miles per gallon will help decrease emissions. Another way to reduce carbon dioxide
emissions is switching electricity production from fossil-fuel-based power plants to renewable sources such as
wind, solar, and hydroelectric. Methane emissions can be reduced by repairing leaks in pipelines and by redu-
cing the world dependency on rice and livestock production. Other ideas to reduce global warming include
supporting laws, treaties, and protocols that reduce the emissions of greenhouse gases, and slowing down the
rate of deforestation while encouraging the replanting of forests.
Laws and Treaties
Enacted by the United Nations Framework Convention on Climate Change, the goal of the
Kyoto Protocol
(1997)
is to achieve stabilization of greenhouse-gas concentrations in the atmosphere at a level that would pre-
vent climate change. The protocol was adopted in 1997 and signed by 187 nations. Under the protocol, 39 in-
dustrialized countries and the European Union are committed to the reduction of four greenhouse gases (car-
bon dioxide, methane, nitrous oxide, and sulfur hexafluoride), along with two groups of gases (hydrofluorocar-
bons and perfluorocarbons). They agreed to a reduction of their greenhouse gas emissions by 5.2 percent from
1990 levels. The United States is one of the few countries in the world that has not signed the Kyoto Protocol.
Loss of Biodiversity
Massive Extinctions from Human Activity
Biodiversity
is the variety of organisms found within a specific geographic area. Increased biodiversity allows
an ecosystem to remain stabile when pressured. A variety of species, for example, provides ecosystems and hu-
mans with many benefits and services.
In addition to diversity of species, biodiversity includes genetic diversity within any single species. For ex-
ample, wild cheetahs have very low gene diversity, so they may be at risk for population decimation by one
kind of pathogen. As each species in an ecosystem finds its role in a community, its
niche,
then a complex eco-
system structure is formed. This promotes ecosystem stability and provides a variety of food sources and habit-
at for flora and fauna. An example of biodiversity is found in Yosemite National Park, which is home to one-
third of all the bird species represented in North America.
As humans have interfered with ecosystems, we have caused biodiversity to decline. The factors that make an
area's biodiversity likely to decline are represented by the acronym HIPPCO, used by many conservation biolo-
gists. HIPPCO stands for
H
abitat destruction, degradation, and fragmentation;
I
nvasive species (nonnative,
exotic);
P
opulation and resource use increases;
P
ollution;
C
limate change; and
O
verexploitation.
Issues Related to Loss of Biodiversity
Issues related to loss of biodiversity as described by the World Resource Institute (2005) are linked to human
activity:
• Overuse and overexploitation
• Pollution and sedimentation
