What is Global Warming? Global warming is the unusually rapid increase in Earth's average surface temperature over the past century primarily caused by the release of greenhouse gases like carbon dioxide. into the atmosphere. Rigorous analysis of all data and lines of evidence shows that most of the observed global warming over the past 50 years or so cannot be explained by natural causes and instead requires a significant role for the influence of human activities. So, lets all stop this effect togethor! Who's with me?