When water evaporates from land and different water bodies, it becomes water vapour. As the air gets warmer, its capacity to hold the water vapour increases. When the water vapour rises, it starts cooling. The water vapour condenses causing formation of droplets of water. When these droplets of water become too heavy to float in air, then they come down as precipitation in the form of either dew, rain, snow, sleet or hail.

Winds can be broadly divided into three types:
(i) Permanent winds: Permanent winds blow constantly throughout the year in a particular direction. Example easterlies and westerlies

(ii) Seasonal winds: Seasonal winds change their direction in different seasons. For example monsoon winds.
(iii) Local winds: These winds blow only a particular period during the day or year in a small area. For example land or sea breeze or Ioo.

Our atmosphere has five different layers. They are:
(i) Troposphere,
(ii) Stratosphere,
(iii) Mesosphere,
(iv) Thermosphere,
(v) Exosphere.
(i) Troposphere : It is most important layer of the atmosphere with average height of 13 km from the earth. The air that we breathe exists here. Almost all the weather phenomena such as rainfall, fog and hailstorm occur here.
(ii) Stratosphere : This layer extends up to a height of 50 km. It presents the most ideal conditions for flying aeroplanes. It contains a layer of ozone gas which protects us from harmful effects of the sun rays.
(iii) Mesosphere : This layer extends up to a height of 80 km. Meteorites burn up in this layer on entering from the space.
(iv) Thermosphere: In this layer temperature rises very rapidly with increasing height. Ionosphere is the part of this layer. This layer extends between 80- 400km. It helps in radio transmission. Radio waves transmitted from the earth are reflected back to the earth by this layer.

(v) Exosphere: It is the uppermost layer where there is very thin air. Light gases such as helium and hydrogen float into the space from here.

1.Yes, global warming is a serious issues of contemporary world. Due to global warming, temperature on Earth is increasing. If it is not controlled, a day will come when all ice caps will melt and everything will get submerged into water.
2.Overburning of fuels like coal and oil causes the greenhouse effect.
3.Using bio-fuel and tree plantation make ways out of global warming.

The pressure exerted by the weight of air on the Earth's surface is called air pressure.
The air pressure is highest at sea level and decreases with height. Horizontally the distribution of air pressure is influenced by temperature of air at a given place.
(i) Low pressure areas are created where temperature is high the air gets heated and rises. It is associated with cloudy skies and wet weather.
(ii) High pressure area is associated with clear and sunny skies which mean areas having lower temperature. Heavy air sinks and creates a high pressure areas. The air always moves from high pressure areas to low pressure areas

Wind is the movement of air from high pressure area to low pressure areas.
There are three types of wind
(i) Permanent Winds The trade winds, westerlies and easterlies are the permanent winds. These blow constantly throughout the year in a particular direction.
(ii) Seasonal Winds These winds change their direction in different seasons. For example, monsoons in India.
(iii) Local Winds These winds blow only during a particular period of the day or year in a small area. For example, land and sea breeze, L00 etc.

The atmosphere is divided into five layers starting from the Earth's surface
(i) Troposphere Its average height is 13 km. The air we breathe exists here. Almost all the weather phenomena like rainfall, fog and hailstorm occur in this layer.
(ii) Stratosphere It lies above the troposphere which extends up to a height of 50 km. This layer is almost free from clouds and associated weather phenomenon, making conditions most ideal for flying aeroplanes. It contains a layer of ozone gas.
(iii) Mesosphere It lies above the stratosphere. It extends up to the height of 80 km. Meteorites burn up in this layer on entering from the space.
(iv) Thermosphere In thermosphere, temperature rises very rapidly with increasing height. Ionosphere is a part of this layer. It extends between 80-400 km. This layer helps in radio transmission. In fact, radio waves transmitted from the Earth are reflected back to the Earth by this layer.
(v) Exosphere This uppermost layer. This layer has very thin air. Light gases like helium and hydrogen float into the space from here.

Distinction between Rainfall and Snowfall

Green plants use Carbon dioxide to make their food and release Oxygen. Humans or animals release Carbon dioxide. The amount of Carbon dioxide released by humans or animals seems to be equal to the amount used by the plants which make a perfect balance. But this balance is disturbed by burning of fuels, which add billions of tons of Carbon dioxide in the atmosphere. As a result, the increased volume of Carbon dioxide is affecting the earth's weather and climate.