Global Warming is the raise in the standard temperature of the atmosphere, oceans, and landmasses of Earth. The planet has warmed (and cooled) many times during the 4.65 billion years of its history. At present Earth appears to be facing a rapid warming, which most scientists believe results, at least in part, from human activities. 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. 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. Like the glass panes in a greenhouse, certain gases in the Earth’s atmosphere permit the Sun’s radiation to heat Earth. At the same time, these gases retard the escape into space of the infrared energy radiated back out by Earth. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide, methane, nitrous oxide, and water vapor, insulate Earth’s surface, helping to maintain warm temperatures. Without these gases, Earth would be a frozen planet with an average temperature of about -18°C (about 0°F) instead of a comfortable 15°C (59°F). If the concentration of these gases rises, they trap more heat within the atmosphere, causing worldwide temperatures to rise. (Chabanier, Jacques)
Within the last century, the quantity of carbon dioxide in the atmosphere has augmented spectacularly, largely for the reason that people flame vast amounts of fossil fuels coal and petrol and its derivatives. Average global temperature also has increased—by about 0.6 Celsius degree (1 Fahrenheit degree) within the past century. Atmospheric scientists have found that at least half of that temperature increase can be attributed to human activity. They predict..........
