Energy and the Environment
Energy is a prime factor in environmental quality. Extraction, processing,
shipping, and combustion of coal , oil, and natural gas are the largest
sources of air pollutants, thermal and chemical pollution of surface waters,
accumulation of mine tailings and toxic ash, and land degradation caused
by surface mining in the United States.
On the other hand, a cheap, inexhaustible source of energy would allow us
people to eliminate or repair much of the environmental damage done
already and to improve the quality of the environment in many ways.
Often, the main barrier to reclaiming degraded land, cleaning up polluted
water, destroying wastes, restoring damaged ecosystems, or remedying
most other environmental problems is that solutions are expensive—and
much of that expense is energy costs. Given a clean, sustainable,
environmentally benign energy source, people could create a true utopia
and extend its benefits to everyone.
Our ability to use external energy to do useful work is one of the main
characteristics that distinguishes humans from other animals. Clearly,
technological advances based on this ability have made our lives much
more comfortable and convenient than that of our early ancestors. They
have also allowed us to make bigger mistakes, faster than ever before. A
large part of our current environmental crisis is that our ability to modify our
environment has outpaced our capacity to use energy and technology
wisely.
In the United States, fossil fuels supply about 85% of the commercial
energy. This situation cannot continue for very long because the supplies of
these fuels are limited and their environmental effects are unacceptable.
Americans now get more than half of their oil from foreign sources at great
economic and political costs. At current rates of use, known, economically
extractable world supplies of oil and natural gas will probably last only a
century or so. Reserves of coal are much larger, but coal is the dirtiest of all
fuels. Its contribution of greenhouse gases that cause global warming are
reason enough to curtail our coal use. In addition, coal burning is the
largest single source in the United States of sulfur dioxide and nitrogen
oxides (which cause respiratory health problems, ecosystem damage,
and acid precipitation). Paradoxically, coal-burning power plants also
release radioactivity , since radioactive minerals such as uranium and
thorium are often present in low concentrations in coal deposits.
Nuclear power was once thought to be an attractive alternative to fossil
fuels. Billed as "the clean energy alternative" and as an energy source "too
cheap to bother metering," nuclear power was promoted in the 1960s as
the energy source for the future. The disastrous consequences of accidents
in nuclear plants, such as the explosion and fire at Chernobyl in the
Ukraine in 1986, problems with releases of radioactive materials in mining
and processing of fuels, and the inability to find a safe, acceptable
permanent storage of nuclear waste have made nuclear power seem much
less attractive in recent years. Between seventy and ninety percent of the
citizens of most European and North American countries now regard
nuclear power as unacceptable.
The United States Government once projected that 1,500 nuclear plants
would be built. In 2002, only 105 plants were in operation and no new
construction has been undertaken since 1975. Many of these aging plants
are now reaching the end of their useful life. There will be enormous costs
and technical difficulties in dismantling them and disposing of the
radioactive debris. Some reactor designs are inherently safer than those
now in operation, but public confidence in nuclear power technology is at
such a low level that it seems unlikely that it will never supply much energy.
Damming rivers to create hydroelectric power from spinning water turbines
has the attraction of providing a low-cost, renewable, air pollution-free
energy source. Only a few locations remain in the United States, however,
where large hydroelectric projects are feasible. Many more sites are
available in Canada, Brazil, India, and other countries, but the social and
ecological effects of building large dams , flooding valuable river valleys,
and eliminating free-flowing rivers are such that opposition is mounting to
this energy source.
An example of the ecological and human damage done by large
hydroelectric projects is seen in the James Bay region of Eastern Quebec.
A series of huge dams and artificial lakes have flooded thousands of
square miles of forest. Migration routes of caribou are disrupted,
the habitat for game on which indigenous people depended is destroyed,
and decaying vegetation has acidified waters, releasing mercury from the
bedrock and raising mercury concentrations in fish to toxic levels.
The hunting and gathering way of life of local Cree and Inuit people has
probably been destroyed forever. This kind of tragedy has been repeated
many times around the world by ill-conceived hydro projects.
There are several sustainable, environmentally benign energy sources that
should be developed. Among these are wind
power, biomass (burning renewable energy crops such as fast-growing
trees or shrubs), small-scale hydropower (low head or run-of-the-river
turbines), passive-solar space heating, active-solar water heaters,
photovoltaic energy (direct conversion of sunlight to electricity), and ocean
tidal or wave power . There may be unwanted environmental
consequences of some of these sources as well, but they seem much
better in aggregate than current energy sources. A big disadvantage is that
most of these alternative energy sources are diffuse and not always
available when or where we want to use energy.
We need ways to store and ship energy generated from these sources.
There have been many suggestions that a breakthrough in battery
technology could be on the horizon . Other possibilities include converting
biomass into methane or methanol fuels or using electricity to
generate hydrogen gas through electrolysis of water. These fuels would be
easily storable, transportable, and used with current technology without
great alterations of existing systems. It is estimated that some combination
of these sustainable energy sources could supply all of American energy
needs by utilizing only a small fraction (perhaps less than one percent) of
United States land area. If means are available to move this energy
efficiently, these energy farms could be in remote locations with little other
value.
Clearly, the best way to protect the environment from damage associated
with energy production is to use energy more efficiently. Many experts
estimate that people could enjoy the same comfort and convenience but
use only half as much energy if they practiced energy conservation using
currently available technology. This would not require great sacrifices
economically or in one's lifestyle.