Archive by category | Palaeoclimate

AGU Chapman Conference: “They walked away”

AGU Chapman Conference: "They walked away"

At the AGU Chapman conference today, Yale archaeologist Harvey Weiss took the prize for an abrupt climate change picture worth a thousand words. Excavating an Akkadian palace in Tell Leilan, Syria, in 2006 and 2008, Weiss’s team found one room with a grain storage vessel smashed on the floor. Lying next to it were a standard litre measure used for rationing grain, and the tablet on which a bureaucrat had been recording the rationing. The artifacts date from about 2190 B.C., when cities and towns of the Akkadian empire in Mesapotamia were being abandoned en masse as the region suffered crushing drought.  Read more

AGU Chapman: Could seafloor vents control atmospheric CO2?

AGU Chapman: Could seafloor vents control atmospheric CO2?

As the Earth has alternated between glacial and inter-glacial periods, the steep climatic ups and downs have gone hand in hand with changes in atmospheric carbon dioxide levels. But where was the CO2 going to and coming from? Scientists have pointed to the ocean – currently a vast sponge for the greenhouse gas.  Read more

AGU Chapman: Meridional madness

AGU Chapman: Meridional madness

Today’s theme at the AGU Chapman Conference on Abrupt Climate Change is that big baddie of climatic tipping points, the shutdown (and rebooting) of the Atlantic Meridional Overturning Circulation, or AMOC. Could this massive system go down again? Tom Delworth of NOAA took on that question and offered up some interesting new modelling evidence.  Read more

AGU Chapman: It’s all about the bumps

A scant 21,000 years ago, Columbus, Ohio, was blanketed by the Laurentide ice sheet. Today it is home to the Byrd Polar Research Centre at Ohio State University, where this morning I sat in a glacially air-conditioned lecture hall watching an animation of that sheet flickering rapidly back and forth across Columbus and the rest of the northern parts of the continent. Such strobe-light climate change from the Earth’s past is the focus of the AGU Chapman Conference on Abrupt Climate Change, being held here this week.  Read more

Holy snakes!

Holy snakes!

Posted on behalf of Roberta Kwok Scientists have found a new way to estimate past climate: snakes. In case you haven’t seen the media flurry, researchers have uncovered the remains of a gigantic snake in northeastern Colombia (which news outlets have described as “” http://features.csmonitor.com/discoveries/2009/02/04/prehistoric-one-ton-super-snake-ate-alligators-for-lunch">Super-snake", “”http://www.google.com/hostednews/afp/article/ALeqM5gvMX4MXQYzy22YM8gMEBTIUR6lFQ">Bus-sized boa", and “”http://www2.canada.com/technology/columnists/grandaddy+snake+world+unearthed+colombia/1252613/story.html?id=1252613">Granddaddy of the snake world", among other things). The newly named Titanoboa cerrejonensis would have measured 13 metres long and weighed about 1,135 kilograms, making it the biggest known snake, living or extinct. Why does this matter for climate predictions? The snake lived 58 to 60 million years ago, around the Palaeocene  … Read more

CLIMAP for the 21st century

CLIMAP for the 21st century

In the 70s and 80s, scientists from around the world worked to reconstruct Last Glacial Maximum (19,000 to 23,000 years ago) sea surface temperatures across the globe under the auspices of the Climate: Long Range Investigation, Mapping and Prediction (CLIMAP) project. Since then, a number of new proxies and seafloor coring and drilling projects have produced a wealth of additional data. In a new paper online this week in Nature Geoscience (subscription required), the MARGO (Multiproxy Approach for the Reconstruction of the Glacial Ocean surface) team members have updated this reconstruction using all the newly available data.  Read more

New Antarctic base could help extend climate record back 1.5 million years

New Antarctic base could help extend climate record back 1.5 million years

A Chinese expedition is expected to start work this week on a new Antarctic base that will faciliate novel research in climate science as well as in other fields, reports Jane Qiu over on Nature News [subscription]. The Kunlun base will be located at Dome Argus, or ‘Dome A’, some 4,093 metres above sea level. It will be China’s third Antarctic research facility and is being built as a legacy of International Polar Year, a major two-year scientific programme that comes to an end in March. According to radar studies of the region, Dome A sits atop ice over 3,000  … Read more