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Climate Change in the Geologic Record. Miriam S. Andres, Angela Hessler, Tim McHargue Carbonate Research & Development Team ETC-Chevron, San Ramon December 2009. Taken from Ruddiman : Earth’s Climate: Past and Future. Temperature in the Geologic Record. www.wikipedia.org.
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Climate Change in the Geologic Record Miriam S. Andres, Angela Hessler, Tim McHargue Carbonate Research & Development Team ETC-Chevron, San Ramon December 2009
Temperature in the Geologic Record www.wikipedia.org
Temperature in the Geologic Record – A Matter of Time Scales Cretaceous Supergreenhouse Anthropocene PETM Younger Dryas www.wikipedia.org
The Cretaceous – Super Greenhouse Climate 2000-1000 ppm; 8x pre-industrial levels 2011 (389 pp) High sea level; abundant inundated shallow shelf areas. one-third of Earth's present land area was submerged Taken from Ruddiman: Earth’s Climate: Past and Future
The Cretaceous – Super Greenhouse Climate Why did it not get warmer and warmer? Taken from Ruddiman: Earth’s Climate: Past and Future
Temperature in the Geologic Record – A Matter of Time Scales Cretaceous Supergreenhouse PETM Anthropocene Younger Dryas www.wikipedia.org
Paleocene-Eocene Thermal Maximum ~56Ma Taken from National Geographic, October 2011
PETM vs. current warming Source: http://www.wunderground.com/climate/PETM
Comparison Source: http://www.wunderground.com/climate/PETM
Temperature in the Geologic Record – A Matter of Time Scales Cretaceous Supergreenhouse Anthropocene PETM Younger Dryas www.wikipedia.org
The End of the Last Glacial Ice retreating but then… Taken from Ruddiman: Earth’s Climate: Past and Future
The Younger Dryas – return to glacial conditions The 90 Minute Hollywood Version
A Lake? Are you serious? Mark Bateman, Sheffield University The prevailing theory holds that the Younger Dryas was caused by a significant reduction or shutdown of the North Atlantic thermohaline circulation in response to a sudden influx of fresh water from Lake Agassiz (size of UK) and deglaciation in North America. But still a lot of uncertainty and contradicting data sets. -> Bolide impact? -> Other outflows?
Whatever the cause – the result impressive: www.earthtimes.org Shakun & Carlson, 2010 • Rate of change: Temperature drop within a human life span (~30yrs) • Global effects: not always cooling, but sometimes drought • Summit of Greenland was ~15°C colder during the Younger Dryas • than today. • In the UK, (fossil beetle) evidence suggests mean annual temperature • dropped to approximately 5°C,and periglacial conditions prevailed in • lowland areas, while icefields and glaciers formed in upland areas.
Temperature in the Geologic Record – A Matter of Time Scales Cretaceous Supergreenhouse PETM Anthropocene Younger Dryas www.wikipedia.org