The American Geophysical Union, which represents some 60,000 scientists who study the Earth, is ready with an explanation of the cause [of climate change] now. Arguably, there is no other group of scientists more attuned to what the planet is doing. This week, the group issued a two-page statement with the headline: "Humanity is the major influence on the global climate change observed over the past 50 years." It added, "Human-induced climate change requires urgent action." http://n.pr/187pPRE