What Is Global Warming?

Global warming is an increase in the average temperature of the earth's surface over time. This rise results from the "greenhouse effect," in which gases such as carbon dioxide trap heat within the earth's atmosphere. The climbing temperatures could cause catastrophic climate change.

In 1896, Swedish scientist Svante Arrhenius publicly predicted that increasing carbon dioxide levels within our atmosphere would raise the temperature of the planet. However, he expected humankind to benefit from the additional warmth. Scientists developed a different view of global warming during the twentieth century. In 1957 geophysicist Roger Revelle and geologist Hans Seuss composed a paper which advanced the theory that burning fossil fuels had contributed to global warming. That same year, American scientist David Keeling started monitoring and documenting an annual rise in carbon dioxide levels. In 1982, Revelle warned that global warming could melt the earth's glaciers and subsequently raise sea levels dangerously. In 1988, NASA scientist James Hansen testified before Congress and declared his near certainty that, based on computer models and temperature measurements, "...the greenhouse effect has been detected, and it is changing our climate now."

The industrial revolution of the late 1700s and the early 1800s brought about a change in the way nations approached labor, manufacturing and energy production. We began to burn large quantities of fossil fuels, including natural gas, coal and oil. While the release of greenhouse gases increased, the amount of oxygen vegetation produced fell as people cut down forests to provide logs for fuel. The scientific journal "Nature" published a study that predicted the Earth's average temperature would rise between 3.6 degrees and 20 degrees Fahrenheit over the next century. However, the average increase over the last century has been only 0.6 degrees Fahrenheit.

Global warming may make some regions more hospitable for longer periods. However, it probably will result in longer, more intense heat waves in the warmer spots of the world. It also may trigger natural disasters, including floods, hurricanes and drought. Increased precipitation and temperatures in certain areas could encourage the breeding of disease-carrying pests, such as mosquitoes. Greater heat also may increase the production of ground-level ozone, a pollutant which can damage your lungs.

Many scientists and writers point to humankind as the sole creator of global warming. Those on the other side of the issue think it's strictly a function of nature. In all probability, both theories contain some truth. A common myth posits that scientists have not reached a consensus about global warming. However, the United Nations Intergovernmental Panel on Climate Change has concluded that global warming poses a genuine threat, and that human activities largely have created the condition. Most reliable polls of the scientific community indicate overwhelming support for the notion that humans are the primary contributors to global warming.

We may be able to decrease our carbon footprint and stop or slow global warming. For example, replacing the incandescent light bulbs in your home with compact fluorescent bulbs can lower your electric bill and reduce carbon dioxide emissions. Walking to your destination instead of taking the car is another way to reduce global warming. Recycling and using recycled products, installing alternative energy sources such as solar paneling and buying energy-efficient device also can contribute mightily.