Renewable Energy Success Stories

Global Warming and Climate Change

Fossil fuels consist mostly of the element carbon. As these fuels burn, the carbon combines with oxygen from the air, and it releases heat energy and carbon dioxide (CO2). Carbon dioxide was not considered a pollutant until recently. Scientists discovered that this gas has been building up in the atmosphere over the last century as we burned fossil fuels. As carbon dioxide builds up in the atmosphere, the gases act like a pane of glass around the earth. Sunlight moves through this "pane of glass" and is absorbed by the earth, where it turns from shorter wavelength light radiation into longer wavelength heat radiation. The longer wavelengths of heat energy cannot pass back out to space through the "pane of glass" in the atmosphere, reflecting the heat energy back to the earth and changing the climate ofthe planet.

A 1999 report from the United Nations’ Intergovernmental Panel on Climate Change projects that the earth's average surface temperature will increase between 2.5°F and 10.4°F in the next 100 years.¹¹ This is in addition to the increase of 0.5° F to 1.1°F that has already occurred since 1860. The panel is made up of two thousand scientists from around the world.

Such a modest rise in the earth’s average temperature could have dramatic effects. Over the past 10,000 years, the earth’s average temperature hasn’t varied by more than 1.8°F. During the last Ice Age, in which much of the North American continent was covered by a kilometer of ice, average temperatures were only 5°F to 9°F cooler than those today. Analysis of ancient ice cores shows that temperatures can change significantly over just a few decades. We will see the effects of climate change within one lifetime. Predicted effects include more severe weather (e.g. hurricanes, tornadoes, drought), spreading of diseases such as the West Nile Virus, destabilization of local ecosystems, and rising sea levels.¹²

In the United States, approximately 25 tons of greenhouse gases are emitted per person every year, the second highest rate of any country in the world.¹³ Fossil fuels burned to run cars and trucks, heat and cool homes and businesses, and power factories are responsible for about 98% of U.S. carbon dioxide emissions.¹⁴ The U.S. has 4.6% of the world’s population but consumes 23% of the world’s energy.¹⁵ This gives us a special responsibility to reduce greenhouse gas emissions.

11 UN Intergovernmental Panel on Climate Change, Climate Change 2001: Synthesis Report, Summary for Policy Makers, April, 1999. Page 8.

12 The Greenhouse Network website.

13 U.S. Environmental Protection Agency (EPA) website.

14 U.S. Environmental Protection Agency (EPA) website.

15 International Energy Agency (IEA), Key World Energy Statistics from the IEA, http://www.iea.org/stats/index.asp.