Global warming - Class 10 PDF Download

Global Warming

Introduction: Global Warming means gradual increase in world’s temperature caused by greenhouse gases. The impact of global warming can be seen in sea level, crops, rainfall, and human health.

What causes Global Warming?

Massive deforestation, burning of fossil fuels, industrial emissions, etc. have resulted to an increase in green-house gases around earth’s atmosphere.

The greenhouse-gases trap Sun rays in the earth’s atmosphere causing the temperature to rise resulting in what is known as global warming.

The heat would have otherwise released if the greenhouse-gases were not present in such huge quantity. The warming of atmosphere due to the presence of greenhouse-gases is called greenhouse effect.

Greenhouse gases

The main greenhouse gas that is responsible for global warming is carbon dioxide(CO2). Others include nitrous-oxide, chlorofluorocarbon (CFC), methane, etc. Greenhouse gases come from various sources.

1. Carbon dioxide (CO2): The major greenhouse gas is Carbon dioxide. The sources of carbon di-oxide includes:

• Burning of fossil fuels.
• Levels increases as a consequence of deforestation.

2. Methane (CH4): Methane is responsible for about 20% of the greenhouse effect. The sources of methane includes:

1. Rice,
2. Paddies,
3. Burning of wood,
4. Cattle,
5. Wetland,
6. Land fields, etc.

3. Chlorofluorocarbon (CFC): About 15% of greenhouse effect is due to these gases. In case of heat absorbing power it is thousand times more effective than CO2. The sources of chlorofluorocarbon includes:

1. Air conditioning industry,
2. foam packaging industry, etc.

4. Nitrous oxide: Nitrous oxide is responsible for 5% of the greenhouse gases. Its sourcesare:

• Coal burning,
• Breakdown of chemical fertilizers,
• Biomass burning, etc.

How to control global warming?

• Stop deforestation (cutting of trees).
• Start and adopt afforestation (establishment of new forests), reforestation (reestablishment of old forests)  and other forest conservation methods,
• Reduce the use of fossil fuels in power and electricity generation.