Is Climate Change Human-caused What is the Evidence If So, what Can/Should we do about it - Essay Example

The need to mitigate and prevent the effects of climate change has become more urgent than ever before. Thus, it is important to establish the causes of the phenomenon in order to implement appropriate preventive measures. According to UNFCCC, climate change is caused by both human and natural activities (7). Although the earth has historically experienced climatic fluctuations since its formation, the current changes are of unprecedented intensity. However, before examining the contribution of human activities to climate change, it is important to examine the natural contributing activities briefly.

Crowley (271) indentified volcanic activity, ocean currents, and changes in the intensity of solar radiations and the earth’s planetary movements as the major natural contributors to climate change. Volcanic eruptions emit particulate matter and greenhouse gases, especially carbon dioxide and sulphur dioxide. Vast amounts of greenhouse gases emitted by the volcanic activities have the potential of causing global warming (UNFCCC, 18). However, some of the most significant volcanic eruptions in the world caused negligible climatic changes in the world.

For instance, the 1991 eruption of Mount Pinatubo in Philippines emitted about 10 cubic kilometers of emissions, which lowered the global temperature by about 0.5oC (Climate Change Challenge). However, the emissions from the recent eruption of Eyjafjallajokull in Iceland were much less compared to Pinatubo. Rather than causing global warming, the aerosols emitted in volcanic eruptions produce a cooling effect on earth because they reflect solar heat to the atmosphere (Climate Change Challenge).

The contribution of ocean currents to climate change remains uncertain. However, ocean currents transfer vast amounts of heat energy across the globe causing significant climatic fluctuations by disrupting precipitation patterns. The tilting of the earth as it rotates around the sun causes significant climatic changes. A large tilt of the earth increases the intensity of temperatures recorded in various seasons. This implies higher temperatures in summers and lower temperatures during winter (Climate Change Challenge).

The sun is the primary source of energy in the planet and fluctuation in its energy output could cause significant climatic changes. However, the sun’s energy output has remained fairly constant for over two hundred years, implying that solar radiations play an insignificant role in causing climate change (Lean, 116). Lean argues that increase in the intensity of solar energy would cause significant increase in temperature in all atmospheric layers, including the upper atmosphere. However, the prevailing climatic change is characterized by temperature increase in the lower atmosphere, while the upper section remains cold (118-120).

Human activities are the largest cause of climate change a fact demonstrated by the unprecedented increase of greenhouse gases in the atmosphere. Greenhouse gases include sulphur and nitrogen oxides and hydrocarbons such as methane. However, carbon dioxide is the major component of greenhouse gases. In the past one hundred years, carbon dioxide concentration in the atmosphere increased significantly from 278 to 379 parts per million recorded in 2005 (IPCC, 28). During the same period, the average temperatures increased by an average of 0.

7oC (UNFCCC, 6). The temperature incre