- Black Carbon (a.k.a. the main component of soot)--second only to CO2 in the amount of heat it traps in the Earth's atmosphere. The color black absorbs heat, and soot falling on glaciers and snow can make them melt faster.
- Methane--a highly potent greenhouse gas originating from decaying or digested vegetable matter. Methane leaks from the Arctic are a huge worry for environmentalists, as they could release large amounts of the gas into the air.
- Hydrofluorocarbons--another greenhouse gas typically used in refrigeration or A/C systems.