What do the major greenhouse gases include?

• carbon dioxide (CO2)
• methane (CH4)
• CFCs (chlorofluorocarbons)
• water vapor (this is a natural greenhouse gas that we cannot control)

To understand the greenhouse effect though, we need to know the actual order of these gases:

1. Water vapor produces most of the greenhouse effect (over 80%). When the IPCC models look at the predicted warming they include increases in water vapor to produce the warming trend they predict.

2. Next in line is CO2. This makes up 0.04%. Man is a minor contributor (about 6%) of this gas.

3. Third line line is Methane. Man is a contributor here as well. In fact man makes up about half of this gas. The total warming factor attributed to Methane is well under 1% of the whole issue though.

4. All other gases are considered too minor to be a factor. In fact CFC's are blamed for reducing ozone which has, in turn, caused the Antarctic to cool. The values f these minor gases are below the threshold of error in terms of total greenhouse effect and are ignored by models.