How do human activities contribute to Greenhouse Gas Emissions & Global Warming?
Global warming can occur from a variety of causes, both natural and human induced. Volcanic eruptions,
changes in the earth's orbit and earth's orientation toward the sun, are some of the natural causes of
Global Warming. However, since the beginning of Industrial Revolution, the concentrations of greenhouse
gases (GHGs) in the atmosphere have escalated drastically due to human activities such as:
DEFORESTATION - Forests act as the largest sink as well as source
of carbon. However, by depleting almost 70% of the earth's forest
cover for agriculture and other development projects, we have
caused two-way damage. Firstly, slashing trees releases vast
amounts of carbon (that was previously stored in the plant body)
in the form of carbon dioxide into the atmosphere; Secondly, due
to deforestation, the number of trees available to absorb and
recapture the atmospheric carbon dioxide is reduced drastically.
As a result, the carbon dioxide concentrations in the atmosphere
increase drastically.
FOSSIL FUEL USAGE - Coal, oil and natural gas have originated
from the decomposition of plant and animal matter. These fossil
fuels are rich in carbon and emit vast amounts of carbon dioxide,
nitrogen oxides and sulphur dioxide when ignited. Carbon rich
fossil fuels are being extensively used for generating electricity
for artificial power as well as at homes and industries as a fuel.
Almost 70% of rural and semi-urban India is still dependent on
coal, Kerosene and wood for satisfying their everyday energy
requirements.
ENERGY - Every human activity involving electricity like
watching TV, switching on the fan etc, emits GHGs. It is
estimated that in India, nearly 80% of the energy requirements
are satisfied by fossil fuels alone. Renewable sources of energy
have not yet attained popularity in our country. Most of our
power comes from thermal power stations that use coal, are one
of the largest emitters of carbon dioxide. The energy sector
alone accounts for 21.3% of annual greenhouse gas emissions
globally.
TRANSPORTATION - The transportation sector is responsible for
about 14% of global GHG emissions every year. Road
transportation sectors like cars and buses are responsible for
emission of huge volumes of GHGs. However, it is the aviation
sector that emits the most GHG per traveler/ km and is
responsible for nearly 2% of all GHG emissions.
INDUSTRY - Industrial emissions account for 16.8% of annual greenhouse gas emissions. The industries are
largely dependent on fossil fuels for their energy needs. They consume vast amounts of coal and other
fossil fuels and ultimately emit huge quantities of greenhouse gases. Apart from captive power
generation, the production cycle and industrial transport also contribute significantly to GHG emissions.
AGRICULTURE - Agriculture is responsible for nearly 12.5% of
annual GHG emissions. Particularly cultivation of paddy in
flooded rice fields emits significant quantities of methane gas,
the second largest greenhouse gas. Even cattle and other farm
animals generate small quantities of Methane (from belching).
Clearing of vegetation for agriculture (slash and burn method)
and biomass burning contributes to almost 10% of the annual
GHG emissions.
WASTES - The decomposition of wastes in the municipal garbage
dumps and sanitary landfill sites (especially the anaerobic
decomposition of organic waste) emits large quantities of
methane gas. Open burning of solid wastes, which is quite
common in our country, generates a lot of smoke in addition to
emission of gases like carbon dioxide, carbon monoxide, sulphur
dioxide, dioxins, etc.
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