World Climate and Climate Change

NCERT Solutions for Chapter 12 World Climate and Climate Change Class 11 Geography

Book Solutions

1(i)

Multiple choice questions.
Which one of the following is suitable for Koeppen’s “A” type of climate?
(a) High rainfall in all the months
(b) Mean monthly temperature of the coldest month more than freezing point
(c) Mean monthly temperature of all the months more than 18o C
(d) Average temperature for all the months below 10° C

Answer

(a) High rainfall in all the months
Exercises Page Number 110

1(ii)

Multiple choice questions.
Koeppen’s system of classification of climates can be termed as:
(a) Applied
(b) Systematic
(c) Genetic
(d) Empirical

Answer

(d) Empirical
Exercises Page Number 110

1(iii)

Multiple choice questions.
(iii) Most of the Indian Peninsula will be grouped according to Koeppen’s system under:
(a) “Af” 
(b) “BSh” 
(c) “Cfb”
(d) “Am”

Answer

(d) “Am”
Exercises Page Number 110

1(iv)

Multiple choice questions.
Which one of the following years is supposed to have recorded the warmest temperature the world over?
(a) 1990 
(b) 1998 
(c) 1885 
(d) 1950

Answer

(b) 1998
Exercises Page Number 110

1(v)

Multiple choice questions.
Which one of the following groups of four climates represents humid conditions?
(a) A—B—C—E
(b) A—C—D—E
(c) B—C—D—E
(d) A—C—D—F

Answer

b) A—C—D—E
Exercises Page Number 110

2(i)

Answer the following questions in about 30 words.
Which two climatic variables are used by Koeppen for classification of the climate?

Answer

Temperature and precipitation are two climatic variables are used by Koeppen for classification of the climate.
Exercises Page Number 110

2(ii)

Answer the following questions in about 30 words.
How is the “genetic” system of classification different from the “empirical one”?

Answer

Empirical classification is based on observed data, particularly on temperature and precipitation. Genetic classification attempts to organise climates according to their causes.
Exercises Page Number 110

2(iii)

Answer the following questions in about 30 words.
Which types of climates have very low range of temperature?

Answer

Tropical Humid Climates have very low range of temperature. It exist between Tropic of Cancer and Tropic of Capricorn.
Exercises Page Number 110

2(iv)

Answer the following questions in about 30 words.
What type of climatic conditions would prevail if the sun spots increase?

Answer

When the number of sunspots increase, cooler and wetter weather and greater storminess occur.
Exercises Page Number 110

3(i)

Answer the following questions in about 150 words.
Make a comparison of the climatic conditions between the “A” and “B” types of climate.

Answer

"A" Type of Climate

"B" Type of Climate

It belongs to tropical climate.

It belongs to sub-tropical climate.

It exist between Tropic of Cancer and Tropic of Capricorn.

These are found in low or mid latitudes in the area of subtropical high where subsidence and inversion of temperature do not produce rainfall

Annual range of temperature is very low and annual rainfall is high. 

Very low rainfall that is not adequate for the growth of plants.

The tropical group is divided into three types, namely (i) Af-Tropical wet climate; (ii) Am - Tropical monsoon climate; (iii) Aw- Tropical wet and dry climate.

Dry climates are divided into steppe or semi-arid climate (BS) and desert climate (BW).

Exercises Page Number 110

3(ii)

Answer the following questions in about 150 words.
What type of vegetation would you find in the “C” and “A” type(s) of climate?

Answer

Vegetation in "A" type of climate: The sun being overhead throughout the year and gigh rainfall make the condition appropriate for the growth of plants. It supports rainforests. Tropical evergreen forests with dense canopy cover and large biodiversity are found in Tropical Wet Climate. Deciduous forest and tree-shredded grasslands occur in Tropical Wet and Dry Climate.
Vegetation in "C" type of climate: Warm temperate climates extend from 30° - 50° of latitude mainly on the eastern and western margins of continents. These climates generally have warm summers with mild winters. It is same as tropical forest. The forests have trees, shrubs and bushes. Broadleaf trees provide a continuous and dense canopy in summer and shed their leaves in winter. The shorter trees and shrubs of different heights and grow rapidly in summer and warm spring. Ferns, mosses and other plants which grow quickly in spring but disappear in winter.
Exercises Page Number 110

3(iii)

What do you understand by the term “Greenhouse Gases”? Make a list of greenhouse gases.

Answer

A greenhouse is made up of glass. The glass which is transparent to incoming short wave solar radiation is opaque to outgoing long wave radiation. The glass, therefore, allows in more radiation and prevents the long wave radiation going outside the glass house, causing the temperature inside the glasshouse structure warmer than outside. Due to the presence of greenhouse gases, the atmosphere is behaving like a greenhouse. The atmosphere also transmits the incoming solar radiation but absorbs the vast majority of long wave radiation emitted upwards by the earth’s surface. The gases that absorb long wave radiation are called greenhouse gases. The processes that warm the atmosphere are often collectively referred to as the greenhouse effect.
The primary Greenhouse Gases are:

• Carbon dioxide (CO2)

• Chlorofluorocarbons (CFCs)

• Methane (CH4)

• Nitrous oxide (N2O)

• Ozone (O3).

Some other gases such as nitric oxide (NO) and carbon monoxide (CO) easily react with GHGs and affect their concentration in the atmosphere.
Exercises Page Number 110