Watson, Robert T. ‘’Human Activity Causes Global Warming’’ Global Warming. Ed. James Haley. San Diego: Greenhaven press, 2002 Opposing Viewpoints in Context.Web.3 Aug.2015. Global climate changes, including episodes of global cooling and warming, have occurred many times throughout earth’s history as a result of natural variations in solar radiation, atmospheric chemistry, oceanic and atmospheric circulations, volcanic eruptions, and other factors. However, it’s primarily caused by human activities that started during the …show more content…
Nagel, and Eric V.D. Luft. ’’Is Present Global Warming due to more to Human Activity than to Natural Geologic Trends’’ Science in Dispute. Vol.3. Detroit: Gale, 2003.82-91. Opposing Viewpoints in Context.Web.03 Aug.2015.The atmospheric concentration of greenhouse gases are changing due to human activities. The atmospheric concentrations of greenhouse gases increased because of human activities, primarily due to the combustion of fossil fuels (coal, oil, and gas), deforestation and agricultural practices, since the beginning of the pre industrial era around 1750: carbon dioxide by nearly 30%, methane by more than a factor of two, and nitrous oxide by about 15%. Their concentrations are higher now than at any time during the last 420,000 years, the period for which there are reliable ice core data, and probably significantly longer. In addition, the combustion of fossil fuels has also caused the atmospheric concentrations of sulfate aerosols to have increased. Greenhouse gases tend to warm the atmosphere and, in some regions, primarily in the northern hemisphere, aerosols, tend to cool the atmosphere. The weight of scientific evidence suggests that the observed changes in the earth’s climate are, at least in the part, due to human activities : climate models that take into account the observed increases in the atmospheric concentrations of greenhouse gases, sulfate aerosols and the observed decrease in ozone in the lower stratosphere, in conjunction with natural changes in volcanic activity and in the solar activity, simulate the observed changes in annual mean global surface temperature quite well. This, and our basic scientific understanding of the greenhouse effect, suggests that human activities are implicated in the observed changes in the earth’ climate. I will use this current issue in my research to provide causes of global climate change as the result of human