http://en.wikipedia.org/wiki/Global_cooling
Global cooling was a conjecture during the 1970s of imminent cooling of the Earth's surface and atmosphere culminating in a period of extensive glaciation. This hypothesis had little support in the scientific community, but gained temporary popular attention due to a combination of a slight downward trend of temperatures from the 1940s to the early 1970s and press reports that did not accurately reflect the full scope of the scientific climate literature, i.e., a larger and faster-growing body of literature projecting future warming due to greenhouse gas emissions. The current scientific opinion on climate change is that the Earth has not durably cooled, but undergone global warming throughout the 20th century.[1]
The earth goes through stage, it cooled in the 1970s, now its warming.
