What Is Global Warming?

What is global warming? What causes it? What are the consequences of global warming? What can be done to prevent it?

Global warming is the increase in the Earth's average temperature near-surface air and ocean and its projected continuation in future years. The Greenhouse effect is one of the reasons that is responsible for global warming. Greenhouse effect is the excess heating of the planet due in part to carbon dioxide and other pollutants trapping too much heat close to the Earth's surface (Bell et al, 2001).

Carbon dioxide is the largest source of the greenhouse gases. It occurs as a natural consequence of respiration. (Enger, 2002). The natural causes of the Green house effect are the emissions of gases like nitrous oxide, carbon-di-oxide, methane, ozone and water vapour.

Deforestation also contributes to global warming. Trees play a critical role in the absorption of carbon dioxide. Climate change is a likely effect of global warming. These climate changes would impact on human and other living things. There will also be changes in the coastal areas and increased activities in storms and hurricanes.

Ozone depletion is another concern in relation to global warming. The ozone is a molecule consisting of atoms of oxygen, which absorbs much of the

sun's ultraviolet energy before it reaches the earth's surface. Too much exposure to these ultraviolet rays can cause skin cancer, cataracts and other health complications for human beings.

Health impacts are consequences of global warming. Environmental change may alter the distribution of disease vector and possibly their numbers (Barrow, 1995). Heat stress and respiratory problems such as asthma, allergic disorders are likely due to air quality problems as a result of climate change.

There will be challenges to agriculture. Climate affects crop production. Irrigation demands will have to be increased in order to cope with the hot climate. Droughts can also contribute to the deterioration of crops and these factors will more adversely affect the people living in the poorer nations