Q.26. Write short note on climate change.
Ans. Climate Change: -
Climate is the average weather of an area. It includes general weather
condition, variation according to season etc. Due to stability of climate the
practice in agriculture is possible. But even a small change in the climate may
disturb the agriculture. Various anthropogenic activities are contributing in
the climate change.
Effect Of Climate
Change: -
1. Migration of animals including humans.
2. Disturb the hydrological cycle.
3. Climate change can result in floods and droughts.
4. Green house gases results in increasing in average
global temperature.
Q.27. Name and discuss their contribution to
global warming. What can be the effects of global warming? What are the
remedial measures? (AKTU. - 2008-09)
Related Question
-
Q. What are green house gasses? Name
and discuss their contribution to global warming. What can be the effects of
global warming. (AKTU. - 2010 - 11)
Q. Discuss the phenomenon of greenhouse
effect. What is its effect? What remedial measures you suggest? (AKTU. - 2012 - 13)
Q. What are “Green House Gases”? How
they are responsible for increase in atmospheric temperature? (AKTU. - 2012 - 13)
Ans. Green House Effect: - (AKTU. - 2011 - 12)
Incident solar
energy a short-wave radiations, mostly in the form of visible light, is
absorbed by the earth’s surface and emitted into space as long-wave infrared
(heat) radiations. There are several gases in the earth’s atmosphere, primarily
water vapour and CO2, that
are transparent to the incoming short-wave radiations but are nearly opaque to
the reflected long-wave radiations. Thus much of the earth’s heat is retained,
which causes a warming effect. This phenomenon is knwon as greenhouse effect,
and the gases that have the ability to absorb reflected long-wave radiations
and produce this effect are called green-house gases.
Their Contribution
To Global Warming: -
The greenhouse gases which cause greenhouse warming of
the global climate (excluding water vapour) are carbon dioxide, methane and a
number of other trace gases like nitrous oxide (N2O), tropospheric ozone, chloro-fluoro carbons (CFCs),
hydro-chloro-fluoro carbons (HCFCs), methychloroform (CH3CCI3),
carbon tetrachloride (CCI4),
sulphur dioxide, fluorine, bromine, iodine, and compounds of nitrogen and
sulphur. Figure shows the estimated contributions of greenhouse gases to global
warming.
Effect Of Global
Warming: -
Speculated scenarios based on global warmings include the following:
(i) Increase in global mean temperature at about
0.3°C per
decade.
(ii) There may be more
warming - up in higher latitudes during late autumn and winter, than in
tropics.
(iii) Flooding of many
coastal areas (lands and islands) due to rising sea levels resulting from the
thermal expansion of the oceans, the melting of glaciers and ice sheet, and
probably, from the melting of polar ice caps.
(iv) An increase in
global average temperature is predicted to increase the amount of water vapour
in the atmosphere (because saturated vapour pressure increases with
temperature) thereby increasing the long-wave optical depth, trapping more
long- wave radiation and increasing the temp-erature further.
(v) Increase in global
average temperature will lead to dislocation of suitable land for agriculture,
and thus may adversely affect the world food production.
(vi) The dislocation and
possible extinction of certain biological species and ecosytems cannot be ruled
out.
(vii) Increase it the
severity of storms.
(viii) Other effects include more
evapotranspiration in tropics, alteration in existing precipitation patterns,
effect on hydrological cycle, effect on human health (like heat strokes), etc.
Remidial
Measures: -
Sicne, CO2 accounts for about half of the greenhouse gases and there is a
strong evidence linking temperature and CO2 changes, therefore, the best way to solve this problem of global
warming due to increasing concentration of CO2 is
to use sources of energy that do not produce carbon dioxide - such as wind,
hydroelectric, geothermal, solar, tidal and nuclear energy. Similarly, the
emissions of other greenhouse gases in the atmosphere should also be stopped to
prevent the enhanced greenhouse effect.
