Gasoline

Gasoline is refined petroleum, a liquid created when plant and animal matter decay underground for millennia. It contains huge amounts of energy that is usually released through explosions. For this reason, it is extremely useful both as a fuel source and as a weapon. Burning it releases large amounts of greenhouse gasses into the air, though not as much as coal.

Coal

Coal is a solid fossil fuel. It is cheap, more plentiful than oil, and relatively accessible, but releases tremendous amounts of greenhouse gases into the air. Coal can be converted to oil through a series of chemical reactions known as the Fischer-Tropsch process.

Biofuels

Biofuels, such as ethanol and butanol, are fluids created to take the place of fossil fuels, created by distilling or fermenting plant matter, often corn. They burn more cleanly than fossil fuels, and are more renewable, but are also more expensive...