Darvin ContrerasCharles TempleEnglish IV19 January 2018 Global Warming Global warming can be defined as the gradual increase in the overall average global temperature. Over the course of recent years, we have seen the way in which global warming has caused global temperatures to rise, leading to record temperatures year after year, the hottest years ever seen coming in the last three. Global warming has also become a discussion in recent politics as politicians plan and decide policies in order to help contain this growing issue. The effects of global warming can be seen throughout the world in various ways and has affected the environment greatly. Not only does global warming affect the environment but has also affected the way in which humans live their lives. Many are skeptical about global warming, although it is very real. Since we began keeping records in 1880, the overall temperature of the Earth has increased a great 1.69 °F (or 0.94 °C). A great majority of this increase has come since 1970, as the average surface temperature has risen “at an average rate of about 0.17 °C (or 0.3 °F) per decade”. (Dahlman, LuAnn) Although the overall average global temperature has increased, this does not necessarily mean that the whole planet was warmed at a fixed rate. Over this period of time, the average temperatures over land has warmed faster than ocean temperatures. “In comparison, the average temperature over land temperature has increased at a rate of about 0.18 °F (or 0.10 °C) per decade compared to 0.11 °F (or 0.06 °C) per decade.” (Dahlman, LuAnn) It is only expected that this rate will rise leading to a significant increase in overall global temperature by the end of the 21st century. When discussing global warming, it is very important to note what has caused it. A great majority of environmental scientists concur that the actions of humans are to blame and have brought about this change in global temperature. Many also agree the rise in global warming was started off by the great expansion of industrialization that has taken place within the last one hundred years. These technological advances have resulted in the growth of the ‘greenhouse effect’, a great contributing factor of global warming. The ‘greenhouse effect’ can be defined as the process in which the radiation and warmth emitted by sun rays gets trapped in the earth’s atmosphere by greenhouse gases. Greenhouse gases form a layer in the atmosphere that absorbs and blocks the heat from escaping back into space after bouncing off the earth. This heat is then re-emitted in all directions towards the lower atmosphere, leading to global warming. (Lallanila, Marc) There are several gases that contribute to global warming. Some examples are: water vapor, which is most abundant, carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons (CFC’s). Some of these greenhouse gases are naturally occurring and can be found in the atmosphere, however, human practices are the reason for an unsafe overabundance of several of these. According to the EPA, in 2015 the greatest source of greenhouse gas emissions in the United States came from the production of electricity. This accounted for 29% of the total emissions by the United States. Another great factor was transportation. This came from the use of vehicles such as trains, cars, ships, trucks, and even airplanes and in total accounted for 27% of total emissions. The emission of greenhouse gases through industry was the third largest factor, accounting for 21% of the total emissions. Businesses and homes were less of a factor and contributed 9% of the emissions. A large majority of these used the burning of fossil fuels such as gas, coal and oil, as a source of energy. The great dependence of fossil fuels can be seen as carbon dioxide accounts for 65% of the total global emissions of greenhouse gases. (“Sources of Greenhouse Gas Emissions.”) Throughout the world, agricultural practices are also a great contributor of gases such as methane and carbon dioxide. In rural, and less developed areas, people use the unconventional method of slash-and-burn agriculture. This involves the deforestation of wooded areas by burning, a great contributor to carbon dioxide emissions. Overall, these emissions have contributed to global warming which has had negative and adverse effects on the environment as well as to humans. Ecosystems are very complex biological functions that are greatly affected by slight changes. Global warming has become a disruption to the habitats of many organisms and many have not been able to adapt to the temperature changes. Not only, does global warming affect species living on land, it also affects the ecosystems in the oceans. One of the biggest ways in which this has been seen is in the bleaching of coral reefs. Coral bleaching occurs when water becomes too warm. When coral is stressed by changing conditions, they release an algae known as zooxanthellae, a symbiotic algae living in their tissues, and as a result they turn white.