Katie JochMany people would think that just simply throwing chewed gum onto the street, or their garbage in the ocean will not affect the world. Unfortunately they are wrong; they are affecting the Earth’s atmosphere and the climate.According to the 2010 Anderegg study, 98% of climate researchers publishing actively in their field agree that human activity is the main culprit responsible for global climate change. The study also found that the expertise of researchers unconvinced of human-caused climate change is below that of researchers who agree that human activity is primarily responsible for climate change. (Anderegg, William).When sunlight hits the earth, some of its warmth is absorbed by greenhouse gases in the atmosphere such as carbon dioxide, methane, and nitrous oxide. These gases trap heat and cause the planet to warm through a process called the greenhouse effect. Since the late 1700s, nearly 330 billion metric tons of CO2 has been released into the atmosphere from the burning of fossil fuels, thus increasing atmospheric CO2 from around 280 parts per million (ppm), to an astonishing high of 400 ppm in 2013. Methane gas, which is increasing in the atmosphere due to agriculture and fossil fuel production, traps 84 times as much heat as CO2. Nitrous oxide, primarily released through agricultural practices, traps 300 times as much heat as CO2.Over the 20th century, as the concentrations of CO2, CH4, and NO2 increased in the atmosphere, the earth warmed by approximately 1.4°F.Many say ‘Why care about one degree of warming?. It takes a vast amount of heat to warm all the oceans, atmosphere, and land even by just a degree. In the past, a one degree temperature drop was all it took to for the Earth to go into the Little Ice Age of 1860. And a five-degree drop was more than enough to cover a part of North America under a giant ice sheet 20,000 years ago.The rise in atmospheric CO2 in the last century was obviously caused by human activity, as it occurred at a rate much faster than natural climate changes could produce. Over the past 650,000 years, atmospheric CO2 levels did not rise above 300 ppm until recently. (NASA) Atmospheric levels of CO2 have risen from about 317 ppm in 1958 to 400 ppm in 2013. CO2 levels are estimated to reach 450 ppm by the year 2040.