Millennial Scale Change From Lake El’gygytgyn, NE Russia: Did We Step Or Leap Out Of The Warm Pliocene Into The Pleistocene?

43rd International Arctic Workshop, Amherst, Mass., March 11-13, 2014

Julie Brigham-Grette¹, Martin Melles², Pavel Minyuk³, and the El'gygytgyn Science Team⁴

¹University of Massachusetts, Amherst
²University of Cologne
³NEISRI-RAS Magadan
⁴USA, Germany, Russia

The Pliocene-Pleistocene climate evolution of the Arctic must have modulated the glacial history of Greenland and the onset of Northern Hemisphere glaciation. What is known from the terrestrial stratigraphy of Arctic climate change comes from sites that are spatially and temporally fragmented. In 2009, International Continental Deep Drilling at Lake El’gygytgyn (67^o 30' N, 172^o 05' E) recovered lacustrine sediments dating back to 3.58 Ma that provide the first time-continuous Pliocene-Pleistocene Arctic paleoclimate record of alternating glacial-interglacial change. The warmest/wettest Pliocene interval of the lake record occurs from ~3.58-3.34 Ma and is dominated by exceptional tree pollen implying July temperatures nearly 7-8 ^oC warmer than today, with nearly ~3 times the annual precipitation. Atmospheric CO2 levels are estimated to have been 360-400 ppm implying exceptionally high climate sensitivity and polar amplification. In fact, pollen spectra and modern analog analysis show an unbroken persistence of summers much warmer and wetter than the last interglacial, MIS 5e until nearly 2.2 Ma. Extreme warmth in the Mid Pliocene Arctic occurs at the same time ANDRILL results suggest the West Antarctic Ice Sheet was non-existent.

Using physical, chemical, and biological proxies we find pronounced glacial episodes commenced ~2.6 Ma ago, but the full range of typical Pleistocene glacial/interglacial change was not established until ~1.8 Ma ago. Greenland must have also responded to numerous “super interglacials” during the Quaternary record, with maximum summer temperatures and annual precipitation, especially during MIS 9, 11 and 31, at Lake El’gygytgyn exceeding that documented for MIS 5e. The correspondence of many of these super-interglacials with retreat of the West Antarctic Ice Sheet (Naish et al. 2009) could coincide with intervals when the Greenland Ice was reduced in size. The climate record from Lake El’gygytgyn, especially the history of past interglacials, provides a fresh means of testing the evolving magnitude of polar amplification over time, and the sensitivity of the Greenland Ice Sheet to extreme warmth in the rest of the Arctic.

Brigham-Grette, J., Melles, M., Minyuk, P., Andreev, A., Tarasov, P., DeConto, R., Koenig, S., Nowaczyk, N., Wennrich, V., Rosén, P., Haltia-Hovi, E., Cook, T., Gebhardt, T., Meyer-Jacob, C., Snyder, J., Herzschuh, U.  Pliocene warmth, extreme polar amplification, and stepped Pleistocene cooling recorded in NE Russia. Submitted to Science, 21 November 2012; in revision March 2013.

Melles, M., Brigham-Grette, J., Minyuk, P., and others. 2012. 2.8 Million Years of Arctic Climate Change from Lake El’gygytgyn, NE Russia. Science, 337, 315-320.

Naish, T. et al., 2009. Obliquity-paced Pliocene West Antarctic ice sheet oscillations. Nature, 458, 322-328.

See also Climate of the Past, special issue on Lake El’gygytgyn, 20+ manuscripts.

http://instaar.colorado.edu/meetings/AW2013/abstract_details.php?abstract_id=78

Peter Sinclair: Making the Plio Scene – What the Past tells us about Sea Level

by Peter Sinclair, This Is Not Cool, December 5, 2013

The most sobering evidence of the planet's response to greenhouse gases comes from the fossil record. New evidence scientists are collecting suggests that ice sheets may be more vulnerable than previously believed, which has huge implications for sea level rise.

Link:  http://climatecrocks.com/2013/12/05/new-video-making-the-plio-scene-what-the-past-tells-us-about-sea-level/

WORTH WATCHING: Abrupt Climate Change -- Expecting the Unexpected

by Peter Sinclair, "This Is Not Cool," Yale Forum on Climate Change and the Media, February 13, 2014



Especially pleased to include interviews with more scientists here from our AGU sessions in December.  Links with the unfolding dramas in California and the UK are obvious.

http://climatecrocks.com/2014/02/13/new-video-abrupt-climate-change-and-the-expected-unexpected/

Julie Brigham Grette presents Lake El'gygytgyn sediment core data showing Arctic far more sensitive to changes in CO2

by Peter Sinclair, Climate Denial Crock of the Week, June 2, 2013

Big implications here for DarkSnowproject research.

Skeptical Science:

Here is a must-see 2012 presentation by Julie Brigham-Grette of the University of Massachusetts-Amherst, covering the research her team has been doing into Lake El’gygytgyn (pronouned El-Guh-Git-Kin), a water-filled meteor crater in Arctic Russia that came into being after the impact of a ~1-km-diameter space rock, 3.6 million years ago.

This is incredibly important work because:

• The Lake El’gygytgyn region was not glaciated during any of the ice ages. As a consequence, the more than 300-meter accumulated sequence of lake sediments represents a continuous, undisturbed sedimentary record going all the way back from the present to the aftermath of the impact.

• The team succeeded in 2009 in extracting cores spanning this entire 3.6 million year period.

• The oldest continuous ice core records to date extend back 123,000 years in Greenland and 800,000 years in Antarctica: the Lake El’gygytgyn cores go way back beyond those times and provide an unprecedented view of the past climate of the Arctic.

• Results show that during the Pleistocene (2.588 million to 11.7 thousand years ago), there were a number of super-interglacials – like the present period but much wetter and several degrees warmer in the Arctic, during which the Greenland and West Antarctic ice-sheets didn’t just melt a bit. They disappeared.

Skeptical Science recently covered the new 2013 paper by the same team, describing the Arctic climate in the Lake El’gygytgyn region during the Pliocene, when boreal forests extended well up into the Arctic and summer temperatures were 8 ^oC warmer than they are at present:

The last time carbon dioxide concentrations were around 400 ppm: a snapshot from Arctic Siberia

The data coming from Lake El’gygytgyn strongly suggest that the Arctic climate is highly sensitive to small changes in forcing, warming much faster than the rest of the world in the phenomenon known as Arctic Amplification. In recent years, Arctic Amplification has emerged as a strong modern-day climate signal. To cite but one example, the sea-ice response has been of far greater magnitude than model-based forecasts projected. Now, the past is giving a similar narrative, and understanding the climate of the past gives us our best chance of understanding the climate of the future.

The recent publication of the research discussed above was covered at ClimateProgress, and here is the press release from UMass.

Money quotes at 17:00:  “..Greenland Ice sheet has come and gone much more frequently than
any of us had imagined.”
19:48:  “..extreme warmth many times throughout the last few million  years”  and  “..It may be much easier to get rid of sea ice than we thought before.”

http://climatecrocks.com/2013/06/02/weekend-wonk-bonus-sobering-sediments-from-lake-e/