At first glance, the essay topic on global warming seemed simple. After studying many sites, such as the National Aeronautics and Space Administration (NASA), academic studies, Intergovernmental Panel on Climate Change (IPCC) studies, the International Non-Governmental Panel on Climate Change (IPCC), climate change (NIPCC), etc., global warming is very complicated. It depends on many factors: solar activity, deforestation, increased carbon dioxide from the forest floor, obliquity (change in the tilt of the Earth's armpit), volcanic eruptions, steam water, fossil fuel use, methane gas, cloud cover and other factors. There are many effects on global temperature. Two of the main ways to study this topic are global climate models (GCMs) and observational studies carried out around the world. The majority of scientific studies indicate that the main cause of global warming is increased levels of carbon dioxide released into the atmosphere. Some research shows that natural phenomena are the main source of global warming. This essay will argue that carbon dioxide released into the atmosphere, by human actions, is the primary reason for global temperature changes, secondary, are natural phenomena. Some believe that carbon dioxide in the atmosphere causes a warming effect on the atmosphere. This carbon dioxide, as the majority of studies have shown, has contributed to the increase in global temperature. There has been a lot of research to explain this. One of the best ways to study global warming is to use computer models. Computer models use mathematical equations in a computer program that describe how atmospheric temperature, atmospheric pressure, water, ice, ...... middle of document ...... d/topic/1070188/ Intergovernmental-Panel-on-Climate-Change-IPCC>.Spencer, Roy. ndhttp://www.drroyspencer.com/global-warming-natural-or-manmade/ Web. November 20, 2013. Intergovernmental Panel on Climate Change. Press office, “Human influence on climate is clear”. Press release. September 27, 2013. Web. November 20, 2013.http://www.climate2013.org/images/uploads/WGI-AR5_SPMPressRelease.pdfEuropean Geosciences Union (EGU). “Oldest ice core: 1.5 million-year record of Earth's climate discovered.” ScienceDaily, November 5, 2013. Web. November 29, 2013 http://www.sciencedaily.com/releases/2013/11/131105081228.htmClimate Science Research. "Quantifying once again the scientific consensus on human-caused global warming". Climate science research. May 22, 2013. Web November 20, 2013. http://www.climatesciencewatch.org/2013/05/22/quantifying-scientific-consensus-on-global-warming/