Greenhouse Effect and Climate Change (Part-II)

Total Questions: 50

1. Which of the following is the most fragile ecosystem that will be first affected by global warming? [Uttarakhand P.C.S. (Pre) 2010]

(a) The Arctic and Greenland Ice Sheet
(b) Amazon rain forest
(c) Taiga
(d) Indian Monsoon

Correct Answer: (a) The Arctic and Greenland Ice Sheet

Solution:The Arctic and Greenland ice sheet are the most fragile ecosystem that will be first affected by global warming. The melting of ice in this area will also affect the entire earth.

2. The scientific view is that the increase in global temperature should not exceed 2°C above the preindustrial level. If the global temperature increases beyond 3°C above the pre-industrial level, what can be its possible impact/impacts on the world? [I.A.S. (Pre) 2014]

1. Terrestrial biosphere tends toward a net carbon source.

2. Widespread corral mortality will occur.

3. All the global wetlands will permanently disappear.

4. Cultivation of cereals will not be possible anywhere in the world.

Select the correct answer using the codes given below :

(a) 1 only
(b) 1 and 2 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4

Correct Answer: (b) 1 and 2 only

Solution:According to a report of "Assessing Key Vulnerabilities and the Risk from Climate Change" published by Intergovernmental Panel on Climate Change, if the increase in global temperature exceeds 2 °C above pre-industrial level then Coral mortality will occur around the globe.

It will also result in the transformation of 1/6th of the earth's ecosystem and lead to the extinction of 1/4th known species of the earth. If the earth's temperature increases more than 3°C above the pre-industrial level, the terrestrial biosphere will head towards a net carbon source and 1/5th of the ecosystem will get transformed. This will lead to the extinction of 30% of the earth's known species.

3. As a result of global warming the frequency and Severity of which of the following are increasing due to global warming? [U.P.P.C.S. (Pre) 2018]

(a) Storms only
(b) Hurricanes only
(c) Cyclones only
(d) All of the above

Correct Answer: (c) Cyclones only

Solution:Global warming is an aspect of climate change, referring to the long-term rise of the earth's temperatures. It is caused by increased concentrations of greenhouse gases in the atmosphere, mainly from human activities such as burning fossil fuels, and farming.

The main greenhouse gases whose concentrations are rising are carbon dioxide, methane, nitrous oxide, hydro-chlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and ozone in the lower atmosphere.

Measuring instruments show that water temperatures at the ocean's surface are going up. To some extent, this is a normal pattern: the ocean surface warms as it absorbs sunlight.

The ocean then releases some of its heat into the atmosphere, creating wind and rain clouds. However, as the ocean's surface temperature continues to increase over time, more and more heat is released into the atmosphere.

This additional heat can lead to stronger and more frequent storms like tropical cyclones and hurricanes.

4. Which of the following represents the average increase in earth's temperature during the last century? [U.P.P.C.S. (Pre) 2012]

(a) 0.6 degree Celsius
(b) 0.7 degree Celsius
(c) 0.8 degree Celsius
(d) 0.9 degree Celsius

Correct Answer: (d) 0.9 degree Celsius

Solution:The average increase in earth's temperature during the last century was approx 1°C.

5. How much has the global average temperature risen in the last century? [R.A.S./R.T.S. (Pre) 2021]

(a) 3.0°F
(b) 1.8°F
(c) 3.4°F
(d) 2.4°F

Correct Answer: (b) 1.8°F

Solution:Earth's average surface air temperature has increased by about 1 °C (1.8 °F) since 1900, with over half of the increase occurring since the mid-1970s.

A wide range of other observations (such as reduced Arctic sea ice extent and increased ocean heat content) and indications from the natural world (such as pole ward shifts of temperature-sensitive species of fish, mammals, insects, etc.) together provide incontrovertible evidence of planetary-scale warming.

6. Without green house effect, the average temperature of earth surface would be: [U.P.P.C.S. (Pre) 2020]

(a) 0°C
(b) -18°C
(c) 5°C
(d) -20°C

Correct Answer: (b) -18°C

Solution:Without green house effect, the average temperature of earth surface would be about-18°C. The main green house gasses are Methane, Carbon dioxide, Nitrous Oxide, Water vapor and Ozone.

7. What would happen if phytoplankton of an ocean is completely destroyed for some reason? [I.A.S. (Pre) 2012]

1. The ocean as a carbon sink would be adversely affected.

2. The food chains in the ocean would be adversely affected.

3. The density of ocean water would drastically decrease.

Select the correct answer using the code given below:

(a) 1 and 2
(b) Only 2
(c) Only 3
(d) 1, 2 and 3

Correct Answer: (a) 1 and 2

Solution:If phytoplankton of an ocean is completely destroyed for some reason then the ocean as a carbon sink would be adversely affected. Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight to live and grow.

Hence food chains in the ocean would be adversely affected and if it is completely destroyed then the density of ocean water would not decrease drastically.

8. Which of the following statements regarding global warming are correct? [Uttarakhand P.C.S. (Pre) 2002]

1. Melting of polar ice caps and subsequent rise in the sea level is the most important effect of global warming.

2. The sea-level is likely to rise by one meter by 2070 A.D. if the present level of global warming is not controlled.

3. All the coral islands in the world will be submerged.

4. By 2044 A.D, Fiji is likely to be submerged and the rise in the sea level by the same year will pose a grave danger to the Netherlands.

Codes:

(a) 1, 2, 3 and 4
(b) 1, 2 and 3
(c) 1, 3 and 4
(d) 4 only

Correct Answer: (c) 1, 3 and 4

Solution:According to the Intergovernmental Panel on Climate Change, a rise in temperature between 1.4-5.8°C has been estimated between 1990 to 2100 A.D. This would result in melting polar ice caps and subsequent rise in sea level.

As per IPCC, the sea level is expected to rise from 0.33 m to 0.45m from 1990 to 2100 A.D. Hence statement (1) is correct while (2) is not correct.

The rise in sea level is estimated to be 3 mm per year. At Fiji, its 0.15 meter per year. Hence by 2044, Fiji is likely to be submerged.

9. Who had suggested that shifting Earth on its axis is one of the factors, responsible for the climate change? [U.P.P.C.S. (Mains) 2015]

(a) Robert Hooke
(b) Milutin Milankovic
(c) George Simpson
(d) T.C. Chamberlain

Correct Answer: (b) Milutin Milankovic

Solution:According to the astronomical theory of climate change, Earth's movement produces an effect on climate change.

In 1920s, Serbian geophysicist and astronomer Milutin Milankovic theorized that variation in eccentricity, axial tilt and precession of the earth's orbit results in cyclical variation in the solar radiation reaching the earth. This orbital forcing influences climatic pattern on earth.

10. Which one of the following provides the cryogenic indicator of climate change? [U.P.P.C.S. (Pre) (Re Exam) 2015]

(a) Ice core
(b) Fossilized pollen
(c) Tree ring growth
(d) Evaporite Deposits

Correct Answer: (a) Ice core

Solution:An ice core is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica- Greenland or from high mountain glaciers elsewhere.

As the ice forms the incremental building of annual layers of snow, lower layers are older than upper and an ice core contains ice formed over a range of years.

The properties of the ice and the recrystallized clarification needed inclusions within the ice can then be used to reconstruct a climatic record over the age range of the core, normally through isotopic analysis.

This enables the reconstruction of local temperature records and the history of atmospheric composition.

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