Ans: D

Exp:

Climate change refers to long-term shifts in temperatures and weather patterns. Some of the factors responsible for climate change are as follows:

• Volcanoes-  Massive volcanic eruptions change the climate of the earth temporarily. The material that erupts, such as sulphur dioxide, water vapours, ashes, and dust, reaches the lower stratosphere, blocks the sun’s rays, and reduces the temperature of the earth. Eg-The eruption of Mount Pinatubo in 1991.
• Milankovitch oscillations- refer to cycles in the variations in the Earth’s orbital characteristics around the sun, the wobbling of the earth, and the changes in the earth’s axial tilt.  All these alter the amount of insolation received from the sun, which in turn might have a bearing on the climate.
• The burning of fossil fuels like coal and petroleum leads to the release of greenhouse gases. This leads to more absorption of heat and an increase in the earth’s temperature, which will lead to global warming.
• Deforestation– The forests absorb around one-fifth of human-induced carbon emissions. Hence, deforestation has been considered a major contributor to the cause of climate change.
• Changes in solar output– The sunspots are dark and cooler patches on the sun that increase and decrease in a cyclical manner. According to some meteorologists, when the number of sunspots increases, cooler and wetter weather occurs whereas a decrease in sunspot numbers is associated with warm and drier climatic conditions.

Agricultural activities–  Agricultural activities like animal keeping and rice cultivation play a major role in increasing carbon and methane emissions. For example- paddy fields release methane when the field is flooded during the sowing and maturing stages of the crops.

Ans: C

Exp:

The effectiveness of any given Greenhouse gas molecule will depend on the magnitude of the increase in its concentration, its life in the atmosphere, and the wavelength of radiation that it absorbs. The primary greenhouse gases of concern today are 

• Carbon dioxide (CO2), 

• Chlorofluorocarbons (CFCs), 

• Methane (CH4), 

• Nitrous oxide (N2O) and 

• Ozone(O3 )

Oxygen and Argon are not greenhouse gases.

Ans: D

Exp:

The Earth has witnessed many variations in climate since the beginning. Some of the evidence to support this is as follows: 

• • The ring pattern in the trees provides clues about wet and dry periods in the past- Tree rings are the result of the annual growth of trees, which depends on the local climate conditions, such as rain and temperature. They usually grow wider in warm, wet periods and thinner during the cold and dry periods.

• The sediment deposits in glacial lakes also reveal the occurrence of warm and cold periods. 
• The geomorphological features, especially in high altitudes and high latitudes, exhibit traces of the advances and retreats of glaciers.

Ans: B

Exp:

The Mediterranean climate is a type of temperate climate that is found on the western coasts of continents, between 30 and 40 degrees latitude north and south of the equator. E.g., in Central California, Central Chile, and along the coast in south-eastern and south western Australia. These areas come under the influence of subtropical highs in the summer and westerly winds in the winter. Hence, the climate is characterised by a hot, dry summer and a mild, rainy winter. The monthly average temperature in summer is around 25°C, and in winter it is below 10°C. The annual precipitation ranges between 35 – 90 cm. 

Ans: C

Exp:

The Tundra climatic region is a region of permafrost where the subsoil is permanently frozen. This climate offers a brief growing season that encourages low species diversity. The animals and plants of the tundra biome have adapted to survive the harsh climate. The short growing season and seasonal waterlogging support only low-growing plants in this climate. The types of vegetation found in these areas are grasses, small shrubs, low-growing mosses, lichens, small flowering plants, etc. During summer, the tundra regions have a very long duration of daylight. 

The productivity of the tropical rainforest biome is the highest of all biome types in the world.