Introduction Scientists have attributed greenhouse effect or global warming as a significant factor, which is causing climate change and threatening the existence of humanity and other forms of life. Scientist argue that, greenhouse effect occurs when greenhouse gases such as carbon dioxide (CO 2 ), chlorofluorocarbons, methane, and water vapor accumulate in the atmosphere and shield the earth from emitting long wave radiations into the atmosphere. Since the earth surface hardly loses any radiations from the sun into the atmosphere, due to the greenhouse effect, global warming ensues. Scientific studies have shown that human activities are the main cause of global warming because they increase the amount of CO 2 and chlorofluorocarbons in the atmosphere. According to Kerr (2011), exponential anthropogenic emission of greenhouse gases poses a serious threat to stability of earth’s climate and subsequently affects humanity, flora, and fauna negatively (142). Although global warming is a considerable challenge, which climatologists are grappling with, new scientific findings show that CO 2 is not responsible for global warming since its concentration has been relatively stable for centuries. Thus, there is continuing debate as to whether anthropogenic emission of CO 2 is the cause of global warming. To prove that increased amount of CO 2 in the atmospheres does not cause the greenhouse effect and subsequently global warming; this research paper examines scientific debate regarding global warming. Carbon Dioxide and Global Warming Increasing amount of CO 2 in the atmosphere has elicited extensive debate of global warming. Climatologists have warned that exponential increase in levels of CO 2 is posing a considerable threat to the existence of life on earth because it causes global warming. The debate has been raging as to whether global warming is a natural occurrence or an anthropogenic consequence, but there is undisputable evidence that temperature of the earth has been continually rising for centuries. Rahmstorf (2008) argues that, climatologists expect that, by 22nd century, temperature of the earth will rise by 5 o C or more globally, while regionally, it will by more than 10 o C (p.36). Given current trends of human activities, the rise of temperature will continue for more centuries to come if immediate and long-term interventions are not in place to regulate anthropogenic emissions of greenhouse gases. Numerous studies suggest that increase in CO 2 level is concomitant with temperature increase, meaning that CO 2 is responsible for climatic change, which seems to threaten the existence of life on earth. Increase in the levels of greenhouse gases such as CO 2 , chlorofluorocarbons, and water vapor clearly indicate that global warming is a reality that humanity must address or face extinction due to impeding climate change. Although greenhouse gases are many in the atmosphere, CO 2 contributes considerably to climate change because of its abundance in the atmosphere and sources of emissions. Idso and Idso (2011) explain that, preindustrial levels of CO 2 were about 280 parts per million (ppm), but the current level of CO 2 is over 380 ppm (13). Therefore, it means that increasing levels of CO 2 in the atmos