Global_Warming

Global Warming Global warming by definition is an increase in the average temperature of the earth's surface. Since the late 1800's, the average temperature has increased about 0.5 to 1.5 Fahrenheit degrees (0.3 to 0.8 Celsius degree). Scientists disagree about the causes of this warming trend. Some say that the warming trend is a natural occurrence; they say that natural process could cause the rise in temperature. Changes in the path of revolution of the Earth around the sun could cause global warming. Orbital variation changes how sunlight is distributed on the surface of the planet. But, evidence suggests that human activities have caused this unusual change in climate. The greenhouse effect is the major cause. Energy from the sun heats the earth's surface and in turn heat energy is radiated back into space. Greenhouse gasses trap some of this outgoing energy to retain heat and heat the planet. Without this natural process, the global temperature would be much lower than it is now. The problem is that these valuable and necessary greenhouse gases build up in the atmosphere and cause more and more heat to be trapped. This causes a long term warming of the planet. When excess amounts of warming, temperature, global, cause, rise, greenhouse, surface, heat, past, effect, planet, natural, gasses, energy, co2, climate, changes, causes, atmosphere, about, sun, sea, process, problem, ozone, over, dioxide, degrees, change, carbon, average, amounts, activities, years, trend, trap