Abrupt Climate Change (Greenland Ice)
Greenland ice cores showed in the 1990s that climate can jump by several degrees within decades: the climate system can flip, not only drift.
Open in the interactive tree →The 250,000-year record of the Greenland Ice-core Project, published by Dansgaard and colleagues in 1993, showed sudden climate shifts in the last ice age and the last warm period, but an unusually stable climate since the last ice age ended. About 25 Dansgaard-Oeschger warmings occurred in the last glacial period, typically 5 °C within 30 to 40 years, and they appear linked to changes in the North Atlantic's overturning ocean circulation (AMOC); model runs in the mid-1990s reproduced such switches after a pulse of fresh water. These findings are a root of the idea of climate tipping points, which researchers now study for the AMOC, ice sheets and coral reefs.
Prerequisites
- Climate Models1967Ocean-atmosphere models showed how a pulse of fresh water can switch the circulation.
- Ice Cores1987Deep Greenland cores recorded temperature almost year by year.
Unlocks
- Predicting Tipping PointsopenTipping points are the abrupt switches first seen in Greenland ice cores.