"Renewable energy...it just sounds more efficient."
-Dai Hinds
He, namely my brother, is right of course. Renewable energy is energy that can be replenished in a short amount of time. The two most important forms of renewable energy are:

Biomass (e.g wood, crops, and manure)
This is perhaps the most disgusting, but most significant, form of renewable energy. One of the biggest contributors to global warming is something we rely on the most. This, of course, is cars. Biomass can be converted to useable forms of energy. The most important forms are ethanol and biodiesel. These are what hybrid cars run off of. Sadly, biodiesel only supplies about 4% of the energy used in the United States. Scientists are trying to find a way to incorporate it into fuel more in order to cut back on burning fossil fuels and greenhouse gas emissions. It may not be the the perfect solution, but it helps.
Geothermal Energy
Geothermal energy is the energy provided from the heat of the earth. This could help prevent the use of electricity. Could you imagine living without electricity? I had a power outage last summer during a storm for two days that affected me deeply. I recount those two days as if I survived a torture camp. We can recover the heat as steam or hot water and use it to heat buildings or generate electricity. America is actually in the lead on using geothermal energy. I'm sure we will only take on more of a competitive edge based on Obama's first 100 days in office. It is the best way to cut down on greenhouse gas emissions.

If ever you wanna learn more about anything to do with the environment, this is the place that helped me most.