Global warming essentially describes the increase in average air temperature near the earth and ocean surface. As reported by Creamer and Gao (2015), the associated increase in near-surface temperatures is attributed to the increase in the concentration of carbon dioxide and other greenhouse gases and is argued to generate diverse adverse effects on both the environment and society. According to Hertzberg et al. (2017), greenhouse gases can be described as naturally occurring air molecules that can trap heat in the earth’s atmosphere. The United States Environmental Protection Agency (EPA) more explicitly defines the four greenhouse gases: carbon dioxide, methane, nitrous oxide, and fluorinated gases. Carbon dioxide forms the largest percentage of the greenhouse gases, as illustrated in figure 3 below.
Figure 3: US greenhouse gas emissions in 2017 (source: EPA)
From figure 3, four types of greenhouse gases are identified: carbon dioxide, methane, nitrous oxide, and fluorinated gases. In relation to the increased global temperature, Ritchie and Roser (2019) mapped out the increase in levels of carbon dioxide throughout the earth’s history where it was revealed that the level of CO2 concentration in the atmosphere is currently at the highest levels in more than 800,000 years of existence. Refer to figure 4 below, which maps out the CO2 levels over time