To the editor:

I urge Ms. Teresa Gordon (Public Forum, May 23) or any reader who thinks that the current global warming trend is not being sped along by human actions to visit the U.S. Environmental Protection Agency’s Web site on this very subject at www.epa.gov/globalwarming. What you read may surprise you. Even this important government agency equates human activity, particularly the burning of fossil fuels, with increased levels of greenhouse gases and increased global temperatures.

Chief among these greenhouse gases is carbon dioxide, which traps the heat from the sun in our atmosphere, essentially preventing the heat from being reflected back into outer space. Coincidentally, carbon dioxide makes up more than 90 percent of the Martian atmosphere. While little is known about why the polar caps on Mars are receding, it can be speculated that this gas is having a similar warming effect.

Although we can only speculate how much of an impact humans have, it cannot be disputed that we are causing significant changes to our planet. The EPA estimates that the average American contributes more than 6 tons of these greenhouse gases to the atmosphere annually. Perhaps visiting this Web site will increase your understanding of the current predicament concerning our atmosphere; maybe you can even learn some pointers on how to lessen the output and effects of greenhouse gases. If you do not have Web access at home, please visit your local library. They even have staff to help you find this valuable Web site.

Bill Owecke,

Lawrence