issues on global warming

Global warming results from the greenhouse effect caused by, amongst other things, excessive amounts of greenhouse gases in the earth’s atmosphere from fossil fuel burning. It would seem then, that the other by-products which cause global dimming may be an ironic savior. A deeper look at this, however, shows that unfortunately this is not the case. Burning of fossil fuels is creating two effects Two effects of fossil fuel productions are: * Greenhouse gases that cause global warming * By-products which are pollutants that cause global dimming What is global dimming? Fossil fuel use, as well as producing greenhouse gases, creates other by-products. These by-products are also pollutants, such as sulphur dioxide, soot, and ash. These pollutants however, also change the properties of clouds. Clouds are formed when water droplets are seeded by air-borne particles, such as pollen. Polluted air results in clouds with larger number of droplets than unpolluted clouds. This then makes those clouds more reflective. More of the sun’s heat and energy is therefore reflected back into space. This reduction of heat reaching the earth is known as Global Dimming. The death toll that global dimming may have already caused is thought to be massive. Climatologists studying this phenomenon believe that the reflection of heat have made waters in the northern hemisphere cooler. As a result, less rain has formed in key areas and crucial rainfall has failed to arrive over the Sahel in Northern Africa. In the 1970s and 1980s, massive famines were caused by failed rains which climatologists had never quite understood why they had failed. The answers that global dimming models seemed to provide, the documentary noted, has led to a chilling conclusion: “what came out of our exhaust pipes and power stations [from Europe and North America] contributed to the deaths of a million people in Africa, and afflicted 50 million more” with hunger and starvation.