Reading Response #5

The Climate Change 2007: Synthesis Report published by the Intergovernmental Panel on Climate Change contains a daunting amount of data and technical terms in which it is easy to get lost. Among this overwhelming amount of information, however, a single and crucial idea stands out: climate change—more specifically, regional and global warming—and its observed effects on natural and human systems are for the most part a result of human activity. Evidence of climate change has been observed in raising air and ocean temperatures, increased melting of snow and ice surfaces, and higher average sea levels (30). There is strong evidence that climate change has also affected the incidence of extreme weather events, precipitation, and may even have had an impact on tropical cyclone activity (30, 40). The impact of climate change on natural systems is related to snow, ice, and frozen ground, hydrological systems, and coastal processes (31). Impact on hydrological systems, for instance, produces effects on the thermal structure and quality of water (32), which can in turn affect human life. But climate change can also have more direct effects on managed and human systems such as agriculture and forestry, human health, and human activities in the Arctic region. In the case of human health, for instance, climate change can cause changes in infectious disease vectors, and it can also increase allergenic pollen during altered allergy seasons (33). For these and several other reasons, and especially after realizing that human activity bears the main responsibility for climate change, it is important to understand its causes.

The causes of climate change are natural drivers, such as solar radiation and natural aerosols, and anthropogenic drivers, such as atmospheric concentrations of anthropogenic greenhouse gasses and aerosols, all of which can act as either cooling or warming drivers (36-37). The Synthesis Report acknowledges that the overall result of climate change, measured by the change in energy balance of the climate system—radiative forcing—, has been of warming, and that warming is chiefly the result of anthropogenic drivers (37-39). Moreover, the concentration of anthropogenic greenhouse gas emissions like carbon dioxide, methane, nitrous oxide, and halocarbons has played the biggest role in causing the warming of global climate (37).

What is interesting to note is that these greenhouse gasses are obviously byproducts of industrial activity, as evidenced by the dramatic increase of emissions since 1750 (coinciding with the beginning stages of the Industrial Revolution) and also by higher rates of change in physical and biological systems and surface temperatures in the Northern hemisphere, where the most industrialized regions of the world are concentrated (32). Energy supply, transport, and industry are the main rubrics of human activity that produce greenhouse gasses, but increasing global income and population also play an important role (36-37). Evidently, industrialization is strongly tied to the processes of climate change. Nevertheless, the potentially adverse effects of climate change impact both industrialized and nonindustrialized areas of the world. This underscores the importance of attaining a profound understanding of the causes and effects of climate change, but also the need to formulate and implement measures to manage the anthropogenic drivers of climate change.