Global Warming: Fact or myth?

WITH THE POLITICAL hype surrounding global warming today, it can be difficult to focus on the truth. Global warming refers to the increasing average temperature of the Earth's atmosphere and oceans. The gradual warming of the earth is a reality. It is scientifically proven that the earth undergoes cycles of climate warming and cooling. The primary uncertainty concerning global warming is whether or not the human influence is magnifying the natural effect. Dr. Keith Blackwell is a forecaster in the Meteorology Department. Dr. Blackwell teaches a course in climate change during the summer semester, though his research area is hurricanes. "Climate change and global warming are very complex issues that we don't fully grasp at this point," Blackwell commented. "Though there is no doubt that human activity is producing a warming influence in the atmosphere, the problem is that we don't understand a lot about what makes the climate change on the natural side of things." Without a complete understanding of Earth's natural climactic processes, it is impossible to determine future changes. "There is a very significant amount of uncertainty as to where the climate is going to be decades into the future," Dr. Blackwell added. The Earth's average temperature has risen in recent decades. Experts expect the atmospheric temperature to continue rising in the future. According to "Climate Change 2007: The Physical Science Basis - Summary for Policymakers," the Intergovernmental Panel on Climate Change predicts that global temperatures are likely to increase by 2.0 to 11.5 degrees Fahrenheit between 1990 and 2100. The evidence is present to prove that global warming is real. The question that concerns scientists is the degree of climate change expected in the future and the resulting consequences that humans may have to face. Alan Sealls, Chief Meteorologist at WKRG News 5, certainly recognizes the changes that the Earth's atmosphere is undergoing. "There is no doubt, from what I've seen, that the Earth as a whole is warming," he said. "It doesn't mean that it is the end of the world; the climate changed in the past, and it will change in the future. We have to recognize that there are going to be changes we will have to adapt to." In addition to the natural cycle of change, the climate can be influenced by external forces. The external factors include volcanic emissions, greenhouse gases, solar activity and variation in the Earth's orbit. Of the four climate modifying agents, the only one that can be credited to humans is the emission of greenhouse gases. Although scientists have yet to determine the individual influence of each factor on the climate, greenhouse gases have been estimated as the leading influence. The main natural greenhouse gases are carbon dioxide, water vapor, methane and ozone. Without the presence of these gases, the Earth would be uninhabitable. The gases create a natural greenhouse effect that warms the planet's surface. However, over-production of these gases can cause atmospheric temperatures to escalate to alarming levels. The recent spike in human greenhouse gas emissions began during the Industrial Revolution. Water vapor causes 36-70 percent of the greenhouse effect on Earth, carbon dioxide accounts for 9-26 percent, methane causes 4-9 percent and ozone is responsible for 3-7 percent of the effect. The concentrations of carbon dioxide and methane have reached their highest point in the last 650,000 years. Fossil fuel burning accounts for three-quarters of human carbon dioxide emissions over the past 20 years. Processes such as deforestation can be credited for the remaining 25 percent of man-made carbon dioxide emissions. The level of carbon dioxide in the atmosphere can also increase due to the breakdown of major carbon sinks. Carbon sink ecosystems, which include forests and oceans, are being broken down by pollutants. Natural gas is comprised mainly of methane. Methane often enters the atmosphere via leaks in natural gas pipelines and fuel transmission. Termites and forests are two natural sources of methane. Although greenhouse gases enter the atmosphere in a variety of ways, the majority of emissions arise from fuel combustion. Greenhouse gases are released into the atmosphere during both the production and transport of fuel. The combustion of fuel for the purpose of generating electricity accounts for 17 percent of emissions. The USA Meteorology Department houses several atmosphere experts. Dr. Bill Williams, the director of the department, is apprehensive about blaming humans for recent climate changes. "The Earth has been warming up since the Ice Age 10,000 years ago. I think that there is sometimes a rush to judgment in blaming man for these changes. It is very hard to compare the past and present and even more difficult to determine if the overall climate change is a natural cycle or man-induced," Williams explained. Williams continued by explaining that humans have the power to reduce the amount of greenhouse gases they are putting into the atmosphere. "There are certain things that can be done in the environment to reduce emissions. Excessive pollution of the air, lakes and streams certainly could be curbed," he said. "Some of these things should be done, but not in a radical way." Possible consequences of increasing global temperatures are a rising sea level and changes in the amount and pattern of precipitation. These changes may, in turn, increase the frequency and intensity of events such as floods, droughts, hurricanes and tornadoes. Varying agricultural yields, glacier retreat and species extinction are also possible consequences of advancing atmospheric temperatures. Although any of these events can be linked to warming, it is not easy to connect specific events with global warming. "Although severe weather has been a big factor in global warming, I cannot say that increased storms and hurricanes are caused by man," Dr. Williams stated. The United States is currently the primary producer of carbon dioxide in the world. Recently, America has taken steps to reduce greenhouse gas emissions. In 1998, Vice President Al Gore symbolically signed the Kyoto Protocol to the United Nations Framework Convention on Climate Change. The Kyoto Protocol in an amendment to the international treaty on climate change. Any country that ratifies the agreement commits to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if emission levels are maintained or increased. Although the Kyoto Protocol is non-binding on the United States because it has not been ratified by the Senate, it is a symbolic representation of our commitment to reducing the emission of greenhouse gases.