If it won’t be done from the top down, we’ll prove its value from the grassroots up! Definition: Greenhouse gases are those gases, mostly carbon dioxide (), that, when introduced into the atmosphere, prevent the sun’s heating light energy from radiating back into space, resulting in a global increase in atmospheric temperature. is produced mostly via coal-fired energy production and vehicle exhaust, both of which the US creates more than any other nation on earth. When the atmosphere heats up, storms become more frequent and more violent. (Katrina may be a mild example.) Ice caps melt, which could cause vast damage to coastal areas like New York City and Bangladesh; famine increases significantly due to major disruptions of the food chain, from fish to crops, and more.