Tag: global environmental change

Questions Related to global environmental change

The best solution to combat greenhouse effect is

  1. To use diesel vehicles

  2. To stop infra-red from entering the earth

  3. Afforestation and grow abundant plants

  4. All of the above


Correct Option: C
Explanation:

The best solution to combat greenhouse effect is to plant trees. Trees absorb carbon dioxide and give off oxygen. A single tree will absorb approximately one ton of carbon dioxide during its lifetime.

CO$ _2$, CH$ _4$, N$ _2$O and CFCS are called as green house gases because they can absorb

  1. Ultraviolet radiation

  2. Long wave infrared radiation

  3. Visible light radiation

  4. X-rays radiation

  5. $\gamma$-rays radiation


Correct Option: B
Explanation:

Greenhouse gases are the gases which contribute to global warming. When the concentration of these gases increases in the atmosphere they form a layer which traps the solar radiation. Due to the trapped long wave infrared radiation, the temperature of the earth increases which leads to global warming. So the correct answer is option C.

If CO$ _2$ is absent in atmosphere of earth then 

  1. Temperature will decrease

  2. Temperature will increase

  3. Plants will flourish well

  4. No effect


Correct Option: A
Explanation:

The total carbon dioxide content in the atmosphere is 0.03%. The percentage of carbon dioxide is balanced by respiration and photosynthesis. Solar radiation falls on earth's surface heating it, while a small proportion is reflected back, and earths surface re-emits heat in the form of infrared radiation but part of this does not escape into space as atmospheric gases (e.g., carbon dioxide, methane, etc.) absorb a major fraction of it. These gases like carbon dioxide and methane are commonly known as greenhouse gases because they are responsible for the greenhouse effect. Increase in the level of greenhouse gases has led to considerable heating of earth leading to global warming. Thus, the correct answer is option A..

In the absence of greenhouse gases, the temperature of earth's surface will fall to

  1. $0^o$C

  2. $-5^o$C

  3. $-10^o$C

  4. $-20^o$C


Correct Option: D
Explanation:

Without the Greenhouse gases, the average temperature of earth would be 0$^{o}$ F or -20$^{o}$ C. The naturally present Greenhouse gases allow most of the incoming solar radiations to warm the earth surface and do not let the thermal radiations to escape into the space. However, anthropogenic contribution to the Greenhouse gases increase the level of solar radiations trapped and thus increase the overall temperature leading to global warming.

Hence, the correct answer is '-20$^{o}$ C'.

Green house effect is warming due to

  1. Infra-red rays reaching earth

  2. Moisture layer in atmosphere

  3. Increase in temperature due to increase in carbon dioxide concentration of atmosphere

  4. Ozone layer of atmosphere


Correct Option: C
Explanation:

Greenhouse effect refers to the absorption of the sun's radiations by the atmospheric gases like carbon dioxide and trapping of these radiations within the atmosphere. These are subsequently reflected onto the earth's surface and cause an increase in the global temperature, called global warming. Infra-red radiations reaching earth will not increase the temperature. Moisture layer in the atmosphere does not show the greenhouse effect. Ozone layer in atmosphere absorbs the UV within stratosphere so that they do not reach the earth's surface.

Hence, the correct answer is 'Increase in temperature due to increase in carbon dioxide concentration of atmosphere'

Which gas contributes most of green house effect?

  1. CFC

  2. Freon

  3. $CO _2$

  4. $CH _4$


Correct Option: C
Explanation:

Greenhouse effect can be defined as the trapping of the radiations of the sun by the atmospheric gases and the subsequent reflection on the earth's surface causing global warming. There are many greenhouse gases like water vapour, methane, CFCs etc. but carbon dioxide is the major concern because it has contributed to most of the global warming 1750 to 2011 as per IPCC data and it tends to accumulate in the atmosphere. It is released in greater amounts from the vehicular emissions, deforestation, industrial emissions etc. so it constitutes around 81% of the greenhouse gases.

Hence, the correct answer is 'CO$ _{2}$'.

Green house effect is related to

  1. Increased growth of green algae

  2. Global warming

  3. Cultivation of vegetables in houses

  4. Development of terrace gardens


Correct Option: B
Explanation:

Greenhouse effect refers to the absorption of the sun's radiations by the atmospheric gases like carbon dioxide and trapping of these radiations within the atmosphere. These are subsequently reflected onto the earth's surface and cause an increase in the global temperature, called global warming. So, greenhouse effect is related to the global warming caused by the accumulation of greenhouse gases like carbon dioxide, methane, sulphur tetrafluoride etc.

Hence, the correct answer is 'Global warming'.

Warm ocean surge or Peru current that recurs after $5-8$ years in East Pacific along South America is

  1. El Nino

  2. Aye Aye

  3. Mangox

  4. Gulf Stream


Correct Option: A
Explanation:

El Nino is a climate cycle, occurring after 5-8 years in the Pacific ocean which globally impacts weather pattern. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. The cold counterpart of El Nino is called La Nino. The weakening of the trade winds which results in pushing of warm surface water to the west and less cold water to the east cause the effect of El Nino.

Hence, the correct answer is 'El Nino'

Heat that radiates back from green house gases (green house flux) causes

  1. Additional global warming

  2. Thermal inversion

  3. Eutrophication

  4. Smog


Correct Option: A
Explanation:

Greenhouse gases such as carbon dioxide, methane, nitrous oxide, water vapours trap heat radiating from earth towards space making the earth warmer. The increased amount of these gases block Heat from escaping and they present in the earth's atmosphere for more than their expected period. Scientist attributes the cause of global warming to such semi-permanently existing gases 'forcing' climate change.

Hence, the correct answer is 'Additional global warming'.

Excess atmospheric $CO _2$ increases green house effect as $CO _2$

  1. Is opaque to infra-red rays

  2. Is not opaque to infra-red rays

  3. Precipitates dust in the atmosphere

  4. Reduces atmospheric pressure


Correct Option: A
Explanation:

Carbon dioxide is a greenhouse gas. It absorbs the long wavelength infrared radiations. The chemical bond between carbon and oxygen absorb infrared light very well and traps the heat from escaping, so they are considered to be opaque to the infra-red rays as these cannot pass across the carbon dioxide. Carbon dioxide molecules vibrate on receiving energy from the photon and allows molecules to capture the infrared photons (radiation). 

Hence, the correct answer is 'Is opaque to infra-red rays'