Measuring global warming: traditional global surface mean (as in average)

traditional_global_surface_mean
Originally uploaded by Wag the Dog.

Says Paul Fraser at ems.pdu.edu, The greenhouse effect and global warming ARE NOT the same thing.

There is a greenhouse effect, but, if there were not, we would all be dead.

It is becoming increasingly clear that we are also experencing global warming, but, that is a different matter.

The greenhouse effect is the name applied to the process which causes the surface of the Earth to be warmer than it would have been in the absence of an atmosphere. (Unfortunately, the name, greenhouse effect is a misnomer --- more on that later.)

Global warming is the name given to an expected increase in the magnitude of the greenhouse effect, whereby the surface of the Earth will amost inevitably become hotter than it is now.

Earth has warmed by about 1ºF over the past 100 years. But why? And how? Well, scientists are not exactly sure. The Earth could be getting warmer on its own, but many of the world's leading climate scientists think that things people do are helping to make the Earth warmer.

Global Warming: Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities, says
www.epa.gov/globalwarming/kids/gw.html