- Ever since the Industrial Revolution, humans have been burning increasing quantities of fossil fuels
(coal, oil, gasoline, natural gas, etc.) to drive their cars, furnaces, and factories. Burning these fuels
releases carbon dioxide into the atmosphere. The accumulation of carbon dioxide allows more solar
radiation to enter the atmosphere and less heat to escape. This is the so-called greenhouse effect. Most
scientists believe that the greenhouse effect contributes to global warming , a gradual increase in the
world’s average surface temperature.
- It seems that global warming is causing the oceans to rise. That is partly because warmer water
expands and partly because the partial melting of the polar ice caps puts more water in the oceans. In the
this may result in the flooding of some heavily populated coastal regions throughout the world. For
instance, a one-metre (three-foot) rise in the sea level would flood about 12 percent of the surface area of
heavily populated Egypt and Bangladesh.
- Industrial pollution is the emission of various impurities into the air, water, and soil through industrial
processes. It is a second major form of environmental degradation
- Pollutants may affect us directly. For example, they seep into our drinking water and the air we
breathe, causing a variety of ailments ranging from asthma to cancer, particularly among the young and
- They can also affect us indirectly. For instance, sulphur dioxide and other gases are emitted by coal-
burning power plants, pulp-and-paper mills, and motor-vehicle exhaust. They form acid rain, a form of
precipitation whose acidity eats away at, and eventually destroys, forests and the ecosystems of lakes.
Another example: CFCs used to be widely used in industry and by consumers, notably in refrigeration
equipment. They contain chlorine, which is responsible for the depletion of the ozone layer 8 kilometres
to 40 kilometres (5 miles to 25 miles) above the earth’s surface. Ozone is a form of oxygen that blocks
ultraviolet radiation coming from the sun. As more ultraviolet radiation reaches ground level, rates of
skin cancer increase. Although CFC production has now been stopped, CFCs already in the atmosphere
continue to eat away at the ozone layer. In fact, global warming is speeding up the chemical processes
that result in ozone depletion.
The Decline in Biodiversity:
- The third main form of environmental degradation is the decline in biodiversity, the enormous variety
of plant and animal species inhabiting the earth. Biodiversity changes as new species emerge and old
species die off because they cannot adapt to their environment. This is all part of the normal evolutionary
process. However, in recent decades the environment has become so inhospitable to so many species that
the rate of extinction has accelerated to at least 100 times beyond the natural or background rate. Some
15 589 plant and animal species face a high risk of extinction in the near future
- The single richest source of genetic material with pharmaceutical value is found in the world’s rain
forests, particularly in Brazil, where millions of species of life exist. However, the rain forests are being
rapidly destroyed by strip mining, the construction of huge pulp-and-paper mills and hydroelectric
projects, and the deforestation of land by farmers and cattle grazers.
- Genetic pollution is the fourth main form of environmental degradation. It refers to the health and
ecological dangers that can result from artificially splicing genes together Since 1990, governments and