*[[Global warming]]: Supporters of the [[Kyoto Protocol]] (an emissions reduction treaty) say that "[[correlation is not causation]]" when scientists point out the dozens of natural [[climate cycles]] linking changes in sunspots to changes in Earth's air temperature. But their argument for a [[runaway greenhouse effect]] is based on a single period from 1850 to present in which carbon dioxide levels and air temperatures have risen together. | *[[Global warming]]: Supporters of the [[Kyoto Protocol]] (an emissions reduction treaty) say that "[[correlation is not causation]]" when scientists point out the dozens of natural [[climate cycles]] linking changes in sunspots to changes in Earth's air temperature. But their argument for a [[runaway greenhouse effect]] is based on a single period from 1850 to present in which carbon dioxide levels and air temperatures have risen together. |