Greenhouse Gases & Climate Change

Greenhouse gases are gases that trap heat in the atmosphere. Excess heat trapping produces an undesirable increase in the temperature of the earth that can have far-reaching effects on climate, weather patterns, and human health and well-being.

Carbon dioxide is the most important greenhouse gas, because it it produced in such enormous amounts. We noted earlier that during cellular metabolism food components such as glucose, starch, and fats are combined with oxygen to produce energy, and CO2 and water are by- products.


Fuel combustion similarly oxidizes fuels to produce energy, releasing CO2, nitrogen oxides, and sulfur oxides as byproducts.



And photosynthesis in plants is just the reverse of this in that it uses energy in the form of sunlight to convert CO2 and water into glucose and oxygen.


Thus, carbon dioxide is a naturally occurring compound that plays an essential role in the carbon cycle from photosynthesis to cellular metabolism. Nevertheless, the growing combustion of fossil fuels over the past three centuries has pumped enormous amounts of carbon dioxide into the atmosphere.

The iFrame below will enable you to explore the EPA's web pages on greenhouse gases and climate change. Pay particular attention to the links on the upper left hand side of the web page, and be sure to explore the links on

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Consequences of Global Warming

The Clean Air Act

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