Causes for Global Warming

Scientists have spent decades figuring out what causes global warming. The only way to explain the pattern of warming is to include the effect of greenhouse gases emitted by humans in a variety of ways. Most come from the combustion of fossil fuels in cars, factories and electricity production. Carbon dioxide is the gas responsible for most warming. There are also other contributers which include methane released from landfills and agriculture, nitrous oxide from fertalizers, gases used for refrigeration process, and the loss of forest that would store carbon dioxide.

Different greenhouse gases have very different heat-trapping abilities. Some of them can even trap more heat than CO2. A molecule of methane produces more than 20 times the warming of a molecule of CO2. Nitrous oxide is 300 times more powerful than CO2. Other gases, such as chlorofluorocarbons (which have been banned in much of the world because they also degrade the ozone layer), have heat-trapping potential thousands of times greater than CO2. But because their concentrations are much lower than CO2, none of these gases adds as much warmth to the atmosphere as CO2 does.