Short Question Answers : World Climate and Climatic Changes | Geography Class 11 - Humanities/Arts PDF Download

Q. 1. What climatic data are used in Koeppen’s classification of climate ?
Ans. (i) Temperature
(ii)Rainfall
(iii) Evaporation
(iv)Evapo-transpiration
(v)  Water balance.

Q. 2. Which are the two well-known classifications ?
Ans. Many different classifications of climates have been devised. Of these, two classifications are wellknown.
(i) The German meteorologist Wladimir Koeppen devised a system based on temperature and rainfall.
(ii) The American climatologist C. Warren Thornthwaite drew up a classification based on precipitation efficiency.

Q. 3. Divide the world into temperature zones.
Ans. Various attempts have been made by different climatologists to divide earth into different temperature zones. The early Greek philosophers distinguished three temperature zones :
(i) Torrid zone (Hot zone) Between 0°–30° N and S latitudes with a mean annual temperature of more than 20° C.
(ii) Temperate zone.
(a) Warm temperate (10° to 20°C temperature) 30° to 45°N and S.
(b) Cool temperate (0°C to 10°C temperature) 45° to 60°N and S.
(iii) Frigid zone (Cold zone) 60° to 90°N and South latitudes. (Less than 0°C Temp.).

Q. 4. Which type of climate is known for the minimum range of annual temperature ?
Ans. In Equatorial type of climate the annual range of temperature is the minimum (Below 5°C).

Q. 5. Why is the amount of precipitation that defines the humid dry boundary variable ?
Ans. The seasonal distribution of precipitation is observed to define the humid dry boundary of climates. The temperature and potential evaporation also affect it. According to the effect of all these factors, the amount of precipitation varies.

Q. 6. What is the significance of 10°C summer isotherm ?
Ans. 10°C isotherm in summer marks the limit of tree growth. Trees do not grow in Tundra because the temperature is below 1.0°C in Summer.

Q. 7. What are characteristics of Savanna Climate ?
Ans. The annual average temperature is 23°C. The range of temperature is 5°C. The annual rainfall is 160 cm. mostly in summer.

Q. 8. Why the marine West European climate is formed only in a narrow belt along the coast in North and South America ?
Ans. The presence of mountain barriers of the Rockies and Andes limit the West European climate to a narrow belt in Chile and Canada.

Q. 9. Describe the atmospheric distribution of carbon and greenhouse effect.
Ans. The Carbon Cycle and Greenhouse Effect Three of the principal greenhouses gases – carbon dioxide (CO₂), methane (CH₄) and the chloroflorocarbon (CFC) – contains carbon, one of the most common elements in the environment, and one which plays a major role in the greenhouse effect.

It is present in all organic substances, and is a  constituent of a great variety of compounds, ranging from  relatively simple gases to very complex derivatives of petroleum hydrocarbons. The carbon in the environment is mobile, readily changing its affiliation with other elements in response to biological, chemical and physical processes. This mobility is controlled through a natural biogeochemical cycle, which works to maintain a balance between the release of carbon compounds from their source and their absorption in sinks.

Q. 10. Describe the scheme of classification of climates according to Trewartha.
Ans. Trewartha modified Koeppen’s classification of climates and gave some new suggestions. He included empirical as well as genetic both types of classifications.
The main aim of Trewartha was to give a simple scheme of climates so that main types of climate can be identified.
So he tried to keep the number of climates as minimum.
Koeppen’s classification was difficult to remember.

Trewartha divided the earth into five major climatic groups.
1.  A type of Climate—Tropical Humid Climate : These include low latitude areas which have high temperature and high rainfall throughout the year.

There is no winter season. It is sub-divided into three sub-types.
Af = High rainfall throughout the year.
Aw = Low rainfall in winter.
Am = Monsoon type.
2.  B Type of Climate (Dry Climate) This climate is found in tropical Humid and midlatitudes climates. Its sub-types are :
(i) BWh — Tropical dry climate.
(ii) BSh — Sub-tropical steppe climate.
(iii) BWk —Mid-latitude dry climate.
(iv) BSk — Mid-latitude steppe climate.

The demarcation of tropical dry and steppe dry climate is by 32°F isotherm in coldest month.
 3. C Type of Climate — Mid-latitude Humid climate This type of climate has short winter season. It has three sub-types.
(i) Cs—Sub-tropical semi-humid climate.
(ii) Ca — Sub-tropical humid climate.
(iii) Cb— Mid-latitude marine climate.

Cs climate is affected by anticyclones in Summer and Westerlies in winter. Ca climate gets Westerlies in winter. Cb gets Westerlies throughout the year.
4. D Type of Climate This climate is found in high mid-latitudes, where polar winds predominate in winter. It has sub-types :
(i) Da— Humid Continental climate (20°C temp. in hottest month).
(ii) Dh — Humid Continental climate (22°C temp. in hottest month).

(iii) Dc — Sub-polar climate with short summer. (iv) Dd — With coldest month a temp. of – 38°C. 5. E. Type of Climate (Polar climate) There is no summer season. Polar winds blow throughout the year. It has two sub-types : (ET) — Tundra (ii) EF (ice caps), where temp. is below 0°C.