Greenhouse Gases The three most common types of greenhouse gases are Carbon Dioxide (CO 2) Carbon dioxide enters the atmosphere through the burning of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, and as a result of other chemical reactions such as making cementCarbon dioxide is removed from the atmosphere and stored when it is absorbedGWPs can also be used to define the impact greenhouse gases will have on global warming over different time periods or time horizons These are usually years, 100 years, and 500 years A time horizon of 100 years is used by regulators (eg, the California Air Resources Board) CARB maintains a list of GWPs for some common refrigerants One chart that shows just how skewed global emissions are China, the US and the EU produce 14 times more than the bottom 100 countries Global warming is the ultimate international problem It doesn't matter where you live, climate change is the most serious threat the planet faces today Whe