Fill in the blanks:

(a) …………… coming from the sun penetrates the atmosphere and is absorbed by the earth.

(b) Concentration of greenhouse gases has risen rapidly due to …………… .

(c) The oceans serve as a …………… for carbon dioxide.

(d) The degree at which water vapour is present in the air is called …………… .

(e) The ozone layer lies in the …………… between 16 and 50 km above the earth’s surface.

(f) Many …………… spray cans contain harmful chemicals called chlorofluorocarbons (CFCs).

Answer in one word:

(a) Gases used in some air-conditioners, refrigerators and spray-cans that can destroy ozone and trap the heat in the atmosphere.

(b) The outermost layer of the atmosphere that fades into outer space.

(c) The increase in the temperature of the earth due to air pollution.

(d) A form of oxygen that protects life from the ultraviolet rays of the sun.

What is greenhouse effect? How does it lead to global warming?

Name the major greenhouse gases and their sources.