Q.28. Discuss how switching over to a low carbon
economy can help in our efforts towards fighting against the problem of ‘global
warming and climate change’. (AKTU. - 2009 - 10)
Ans. In
order to stabilize the concentration of green house gases (GHGs)at their
present level, their emissions would need to be immediately reduced by 60%.
However, since reduction in the
emission of these gases cannot occur without reduction in industrial activities,
such a change seems very unlikely for political and economic reasons. The need
is, thus, not only to take steps to mitigate the effects of climate change, but
also to prepare ourselves to adapt to the effects of global warming and climate
change. These steps would include:
•
Reduction in the use of fossil fuels
•
Shifting to the renewable energy
sources that do not emit GHGs
•
Increasing the use of energy
efficient and cleaner production technologies and practices
•
Reducing deforestation, adopting
better forest management practices, and undertaking afforestation to reduce the
amount of carbon in the biosphere.
In this way switching over
to a low carbon economy can help towards fighting against global warming and
climate change.
Q.29. What are major impacts of enhanced global
warming. (AKTU. - 2009-10)
Related
Question -
Q. What is global warming. Discuss the
cause, effects and control measure of global warming. (AKTU. - 2009-10)
Ans. Global warming:-
Global
warming is the term which indicate the increase in the average temperature of
the atmosphere. The increased volumes of carbon dioxide and other green house
gases released by the burning of fossil fuels and other human activities,
contribute to the warming of the earth. The amount of heat trapped in the
atmosphere depends mostly on the concentrations of green house gases.
The major
green house gases are carbon dioxide, ozone, methane, chlorofluorocarbons
(CFCs) and water vapours. Due to anthropogenic activities, there is an increase
in the concentration of the green house gases in the air, which result in the
increase in average surface temperature.
Effects:
Go through privious question.
Control
measures:
(i) To cut down the current rate of use of CFCs and fossil fuels.
(ii) Use of renewable energy resources.
(iii) Afforestation.
(iv) Stabilization of population growth.
Q.30. Briefly discuss the problem of automobile
pollution and suggest suitable ways and means to control it. (AKTU. - 2009 - 10, 12 - 13)
Ans. Automobile Pollution: -
The automobile
contributes to a range of environmental problems: increasing air and noise
pollution, adding to solid waste, accelerating global warming, taking a heavy
toll on human life through accidents, using up natural non-renewable resources
like oil and metals, etc.
Lead pollution caused by
automobiles has been a serious problem. Lead was added to petrol to prevent
‘knocking’ in the engine. It is, however, extremely poisonous and tends to
accumulate in most biological systems. Excessive accumulation of lead in the
body can result in paralysis, blindness, and even death. It can also affect the
mental development of unborn children. The addition of lead to petrol is now
banned in most countries.
Ways And Means TO
Control: -
Automobile emissions
can be reduced through various measures:
· Making cleaner and fuel efficient cars.
· Using lead-free petrol
in existing cars.
· Introducing policies
that encourage the building and use of mass transit system and
discourage the use of personal transport. For example, efficient and low-cost
public transport, congestion charges in city centers, seperate lanes for car
pools, heavy tax on personal cars, tax incentives on electric cars, etc.
· Shifting from diesel to
natural gas (CNG) as a fuel for trucks and buses.
Automobile emmisions can be
reduced through various measures:
· Making cleaner and fuel efficient cars.
· Using lead-free petrol
in existing cars.
· Introducing policies
that encourage the building and use of mass transit system and
discourage the use of personal transport. For example, efficient and low-cost
public transport, congestion charges in city centers, seperate lanes for car
pools, heavy tax on personal cars, tax incentives on electric cars, etc.
· Shifting from diesel to
natural gas (CNG) as a fuel for trucks and buses.
Q.31. Explain acid rain
and its effects on environment. (AKTU. - 2008-09)
Related
Question -
Q. What is acid rain? What are the
causes and effects of acid rain? What remedial measures do you suggest? (AKTU. - 2011 - 12)
Q. What is meant by acid rain? How does
it occur? (AKTU. - 2012 - 13)
Ans. Acid Rain: -
The
term acid rain is used to describe all precipitation and/or deposition, which
is more acidic than normal. It results, when gaseous emissions of particularly
SOx and NOx interact with water vapour and sunlight, and
are chemically converted to strong acidic compounds such as sulphuric,
sulphurous, nitric and nitrous acids.
Effects on Environment: -
The
unnaturally low pH of these acid rain changes the pH of the rivers and streams
which in turn has many adverse effects, namely
(a) Death
of the fish, species of algae, bacteria and plant life inhabiting such water
bodies.
(b) Making
the aquatic ecosystem sterile by altering their internal system, thereby
reducing their reproduction (egg-producing) ability and often resulting in
deformation.
(c) Changes
in metabolic rates of organisms depending on acid or base catalysts.
Besides
these, the acid rain increases the acidity of the soil by causing increased
leaching of nutrients such as calcium. There is also an accumulation of
potentially toxic elements. This weakens the population of beneficial earthworms
and indirectly destroys important food sources for small herbivores.
By
contaminating air, water and food, acid rain influences many species at
different levels of the food chain and is a threat to human health and
well-being.
Remedies:
-
Pouring powderd limestone into
water bodies is a rapid, but short lived, method of reducing acidity. A more
permanent, but slow and expensive, method is the liming of surrounding soils.
Some technologies for reducing
emmisions are flue gas desulphurization in powder stations and catalytic
converters and engine modifications in automobilies.
