From Discovery News:Since the recent discovery of abrupt climate change -- that big changes can come quickly -- researchers have been looking for "warning signs" to help us avert "regime shifts" that could suddenly alter things we take for granted, such as storm tracks and weather patterns, sea levels and water supplies.
Greenland temperature profile, from Climate Crash: Abrupt Climate Change and What It Means for Our Future, Joseph Henry Press, 2005. Recognizing a warning sign is tricky, though, because in a system that is subject to abrupt change, small variations can lead to impacts that are all out of proportion. A widely recognized warning sign or "tipping point" is the recent unexpectedly high loss of Arctic sea ice, which could trigger major reorganizations of ocean and atmospheric circulation. This temperature profile derived from ice cores in Greenland (taken from a book I wrote on the subject), shows numerous abrupt climate changes during the past 100,000 years.
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