What's Global Warming?

Global warming is an increase in the earth's temperature due to the use of fossil fuels and certain industrial and agricultural processes leading to a buildup of greenhouse gases (principally carbon dioxide, methane, nitrous oxide, chlorofluorocarbons and water vapor) in the atmosphere. Global warming is also closely related to the greenhouse effect. GHG are indeed transparent to incoming radiation and opaque to outgoing radiation. This prevents some of the penetrating radiations to escape into space producing an increase in the average temperature of the earth, this is the greenhouse effect. Increase in temperatures is expected to raise sea levels, to warm oceans, to flood some coastal regions and finally, some world areas will have more rainfall then before while others will suffer from drought. These effects are highly uncertain because, first global warming is expected to occur over a very long period, therefore, there is no positive evidence on future economic trends and growth, availability of carbon-free technologies and energy prices. Second, global externalities can be compared to a chaos effect, “fluorides released from aerosol cans in Bangkok, for instance, may harm the earth's ozone layer and endanger New Yorkers”.