How Does Global Warming Work?

The Facts

This environment that we know of as "earth" is an incredible and complicated living system. What makes the earth's atmosphere habitable is a natural atmospheric equilibrium that's sustained by the greenhouse effect. This greenhouse effect captures the heat and light from the sun inside water vapors, carbon dioxide, nitrous oxide, methane and other combined chemical vapors, both natural and manufactured.

Some scientists warn that these greenhouse gas concentrations are increasing as a result of human activities like the burning of fossil fuels and deforestation. Increased gas concentrations are said to raise the earth's temperature, thus creating a global warming effect. Other scientists are not so sure this is the case.

Function

In its natural state, the greenhouse effect creates a shield that allows the sun's radiant heat energy into the earth's atmosphere and moves excess heat concentrations out of the atmosphere. When the gas concentrations in this shield are increased, excess gases become trapped inside the atmosphere, causing increased global temperatures.

Carbon dioxide emissions are identified as the most dangerous gases causing this global warming effect. As of 2004, the United States is reported to have produced 19% of the world's energy-related carbon emissions. These emissions come from car exhausts, factory smoke-stacks, and deforestation. As other developing countries begin to increase their carbon emission usage, global levels are expected to increase by 1.8 percent a year.

Effects

Scientists differ as to what the effects of global warming from greenhouse gas are. Evidence shows a rise in sea levels due to melting glaciers and a melting polar ice cap. This change alone has been seen as the cause for increased weather activity as far as storms and storm intensities. Many scientists attribute this to the increase in industrial activity since the 19th century.

Opposing views state there is no way to actually measure global climate changes because of the earth's differing and changing climate zones. Scientists and climate specialists are still unsure as to whether the current global warming pattern isn't a normal occurrence within the earth's life cycle.

Risk Factors

There is a general consensus that human activity within the last century has increased the greenhouse effect. Significant changes have been observed across various ecosystem balances, resulting in the extinction of many animal and plant species.

Findings from the American Medical Association warn that these increases in temperature will increase the occurrence of new infectious diseases, leading to increased illness and mortality rates. The onslaught of new disease types poses a substantial threat to food and water supplies across the globe.

Resources

• Natural Resources Defense Council
• Center for Global Climate Change