The term global warming simply means that the global climate is warming. Humans are popularly assumed to be the cause of global warming. Further, global warming is usually assumed to be harmful to humans and to plant and animal life. Global warming is a commonly discussed and debated scientific topic both in the media and in the scientific community.

Scientific Debate: Existence, Extent, Causes, and Pace

Nearly all of the scientific community agrees that based on surface temperature observations, the global climate warmed by about 0.5° C in the twentieth century. Satellite observations of global temperatures show warming trends between 1970 and 1990 similar to those found in surface observations. Decreases in sea ice cover and global glacier retreat provide corroborating evidence of global warming. A few scientists believe that the warming at weather stations is due to the development of cities around weather stations, but analysis in the...