Global Warming is defined as an increase in the average temperature of the atmosphere, oceans, and landmasses of Earth (John Hart, Encarta). The average surface temperature of Earth is about 15°C (59°F) which over the last century has risen by about 0.6 Celsius degree (1 Fahrenheit degree). Scientists predict further warming of 1.4 to 5.8 Celsius degrees (2.5 to 10.4 Fahrenheit degrees) by the year 2100 (John Hart, Encarta).
The chief cause of this warming is thought to be the burning of fossil fuels, such as coal, oil, and natural gas, which releases into the atmosphere carbon dioxide and other substances known as greenhouse gases (methane, nitrous oxide, water vapors etc). As the atmosphere becomes richer in these gases, it becomes a better insulator, retaining more of the heat provided to the planet by the Sun (John Hart, Encarta).
According to scientists human activities have further modified this natural process, with potentially dangerous consequences. Since the advent of the Industrial Revolution in the 1700s, humans have devised many inventions that burn fossil fuels that has raised the percentage of carbon dioxide in the atmosphere by about 28 percent (Michael Mastrandrea and Stephen H. Schneider, Encarta). Other activities which also have accelerated this process includes deforestation, air pollution, globalization and scientific discoveries.
Hence the predicted effects of global warming are many and various, both for the environment and for human life. Global warming will affect:
Weather
The warmed world will be generally more humid as a result of more water evaporating from the oceans and as water vapor is a greenhouse gas, its increased presence will add to the insulating effect. Greater humidity will increase rainfall, on average, about 1 percent for each Fahrenheit degree of warming. Storms are expected to be more frequent and more intense (John Hart, Encarta)...........
