By Carolyn Harless
In 1988, an organization called the International Panel on Climate Change (IPCC) was formed by government delegates to monitor and provide information concerning climate change. Since then, the IPCC has published four separate reports of their findings, the most recent being in 2007. Written and reviewed by hundreds of scientists, the 2007 reports Summary for Policymakers and Climate Change 2007: Impacts, Adaptations, and Vulnerability gave scientists even more reason to believe that much of global warming was caused by human activity.
According to the IPCC, 1995 to 2006 recorded the warmest temperatures since the mid-1800s. Authors of the article The Physical Science Behind Climate Change, found in the August 2007 issue of Scientific American, pointed out that the odds of this phenomenon are exceedingly small. The same authors, who also partook in part of the IPCC study, also noted that it is more than 90 percent probable that human activity has caused most of the climate warming in the past century.
Causes of Global Warming
Global warming cannot be linked specifically to one primary cause, but the most obvious is the increasing concentrations of greenhouse gases in the atmosphere. While some are natural, including microscopic aerosols from dust storms and volcanic ash, the majority is human-induced. These human-induced greenhouse gases, or long-lived greenhouse gases, consist mainly of carbon dioxide, methane, nitrous oxide and halocarbons. According to the IPCC, other, although less known, human-induced contributors to climate change include stratospheric and tropospheric ozone, surface albedo (or reflectivity) and air traffic exhaust. The IPCC even reported that the levels of these gases had been relatively stable for at least the past 10,000 years, but began increasing rapidly within the past 200 years due to the burning of fossil fuels.
Climatologists, or climate scientists, use a method called radiative forcing to measure the effects of climate change. The authors of the previously mentioned Scientific American article defines radiative forcing as the change in the energy balance of the earth from preindustrial times. Positive forcing pulls the earth to a warmer climate, while negative forcing pulls it to a cooler climate. As of now, the earth is being pulled toward a warmer climate and will continue to do so until the greenhouse gases begin to decrease in the atmosphere. With the earth being pulled this direction, climate will take its toll on the environment.
According to the U.S. Environmental Protection Agency (EPA) website (www.epa.gov), the Arctic is experiencing the most warming due to the greater albedo water has as compared to land. In fact, the IPCC has found that the oceans have absorbed at least 80 percent of the climates heat. As the Arctic waters rise in temperature, so do its sea levels. Sea levels across the globe are rising because as water warms, it expands. Not only is water in the Arctic expanding, but also glaciers and ice sheets are melting, adding more water to the oceans. Between 1993 and 2003, sea levels of the oceans raised 3.1+/- 0.7 millimeters per year and have continued to rise. With the decline of ice in the Arctic, many ice dependant animals will suffer the warm climates consequences, as well as many roads, buildings, pipelines, airports and industrial facilities. These structures are more prone to destruction and destabilization with the Arctic melting.
Of course the Arctic is not the only region affected by climate change. According to the 2007 IPCC report Climate Change 2007: Impacts, Adaptation, and Vulnerability, all regions of the world have been affected by climate change in one way or another. Increased flooding, fires and droughts are only a few of many effects recorded internationally. Quality and availability of freshwater, as well as a decline in agricultural productivity, are major concerns among countries in Africa, Asia, Australia, Europe and Latin and North America. With the warmer climate, water is evaporating more frequently and freshwater is becoming saltier. Small islands, which are already susceptible to natural disasters, are now at an even greater risk of falling victim to hurricanes, tropical storms, beach erosion and other coastal dangers. In fact, some scientists even believe that lower latitudes will fall victim to stronger hurricanes and typhoons; however, the strength to which these storms will have is unknown and more research is needed before the answer can be found.
The United States has also had its fair share of problems due to global warming. For instance, the EPA reports that agricultural activities have either shifted northward or have produced fewer crops in the Northeast, Western and Great Plains regions. Forests are disappearing due to increased fires and insect outbreaks in the Southeast, Gulf Coast, West and Alaskan regions. The Midwest and Great Lakes regions have experienced lower water levels due to increased evaporation and lower water quality, resulting in an abundance of nutrients from water sources causing dense growth of plants and death of animal life due to a lack of oxygen.
Global warming has not resulted in all negative effects in the world. Some areas, such as the Midwest and Northern Europe, have actually increased crop productions, while other areas are taking advantage of the warm climate to boost their tourism opportunities or even lower their heating costs. Though there are few upsides to the warmer climate, the negative effects still outweigh the positive.
Global Warmings Effect on Humans
In 2005, Nature, with the help of the World Health Organization (WHO), published a review on the impact of climate change on humans. According to the article, the rise in temperature also increased the number of noninfectious and infectious health risks for humans. The WHO has reported multiple deaths particularly among the elderly and the very young. Causes of these deaths range from respiratory and heart diseases, due to intensified heat stress and heat-waves. Another major noninfectious cause of death among humans is malnutrition. According to Nature, climate extremes have significantly decreased crop and livestock production. Due to this decrease, regional food supplies are suffering and malnutrition is spreading worldwide.
Though it is only in the preliminary stages of research, the August 2008 issue of Scientific American reported that researchers are in the process of finding out whether there is a link between global warming and kidney stones. Research published in Proceedings of the National Academy of Sciences USA reports that the warmer climate increases the risk of dehydration, which is believed to be a major cause of kidney stones. The study also reports that as many as 2.3 million more people may develop [kidney stones] by the year 2050 as the result of global warming.
Other health related effects of global warming is the increase of infectious diseases including malaria, dengue fever and cholera. According to Nature and the WHO, temperature plays an important role for such carriers of these insect and water-borne diseases. Mosquitoes are known to thrive in warm wet climates and are the carriers for malaria and dengue fever. Cholera is a water-borne disease transmitted through contaminated water and food. Humans in areas with insufficient sanitation systems and poor water quality (due to droughts, for example) are more prone to this disease than those in healthier environments. If not caught in time or treated, these diseases may result in death.
Scientists are continually studying new and existing patterns of climate change and seeking answers on ways to undo the harm done to the environment. So many issues still remain uncertain, however. What scientists are certain about is the fact that if nothing further is done to prevent the increasing climate change, then there will be many more consequences to endure for years to come.