Global warming is the increase in the average temperature of the earth's atmosphere and oceans. Heating of the earth's climate affects all forms of life on the planet. Increasing temperatures in the past century may have resulted from the "greenhouse effect" and the increase in production of gases such as carbon dioxide.
There is a debate on whether the problem of global warming actually exists. A 2004 investigation of the journal Science, however, showed that 75% of 928 articles on global climate change accepted that most of the warming within the last 50 years is "likely to have been attributable to human activities." The remainder did not offer an explanation for climate change.
