Understanding the Impacts of Climate Change

Over the past century, the Earth’s average temperature has increased by approximately 1°F, with 10 of the warmest years on record occurring since 1990. There have been numerous worldwide scientific studies exploring possible contributory factors to this warming trend. The most recent Intergovernmental Panel on Climate Change Third Assessment Report (2001) concluded “new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.”

There is a belief that increasing concentrations of greenhouse gases in the atmosphere are accelerating the rate of global climate change. Many chemical compounds found in the Earth’s atmosphere act as greenhouse gases. Levels of several important greenhouse gases have increased by about 25 percent since large-scale industrialization began around 150 years ago; atmospheric levels of carbon dioxide in particular are higher today than they have been for more than 400,000 years. Carbon dioxide (CO2) is believed to be the largest contributor to the overall increase in greenhouse gases. Relatedly, scientific studies have shown that an increased amount of CO2 by human activities has occurred over the last few hundred years. These specific human activities include burning fossil- fuels such as gasoline, coal, and natural gas, all of which contribute to the buildup of CO2 in the atmosphere. Fossil fuels alone are responsible for approximately 98 percent of U.S. CO2 emissions.

What does all of this mean in terms of specific impacts to the environment? A May 2001 National Research Council study stated, “Greenhouse gases are accumulating in Earth’s atmosphere as a result of human activities, causing surface air temperatures and sub-surface ocean temperatures to rise. Temperatures are, in fact, rising. The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability.” Some believe that the environmental damage will have such severe impact that immediate steps should be taken to reduce CO2 emissions, regardless of the economic costs to advanced nations such as the United States. Yet others refer to the global temperature observations from over thousands of years which indicate that global temperatures fluctuated greatly in the past, long before the introduction of human industrial activity.

While potential future environmental impacts of climate change have yet to be defined in absolute terms, Battelle is positioned to help government policy makers and companies act in the face of this uncertainty. This issue of Environmental Updates highlights Battelle’s role in various climate change activities, including greenhouse gas emissions management, carbon sequestration, and technology strategy evaluations.