The linked July 2015 paper (see also the attached image) includes discussion of paleo-evidence that abrupt collapse of the WAIS helps to trigger Arctic amplification. As DeConto is one of the primary authors and he is also one of the main authors of the Pollard, DeConto and Alley 2015 on ASLR from Antarctic cliff failures and hydrofracturing; I think that we should all take these paleo findings very seriously, including:
"The timing of significant warming in the circum-Arctic can be linked to major deglaciation events in Antarctica, demonstrating possible interhemispheric linkages between the Arctic and Antarctic climate on glacial–interglacial timescales, which have yet to be explained."
Coletti, A. J., DeConto, R. M., Brigham-Grette, J., and Melles, M.: A GCM comparison of Pleistocene super-interglacial periods in relation to Lake El'gygytgyn, NE Arctic Russia, Clim. Past, 11, 979-989, doi:10.5194/cp-11-979-2015, 2015.
http://www.clim-past.net/11/979/2015/cp-11-979-2015.pdfhttp://www.clim-past.net/11/979/2015/cp-11-979-2015.htmlAbstract: "Until now, the lack of time-continuous, terrestrial paleoenvironmental data from the Pleistocene Arctic has made model simulations of past interglacials difficult to assess. Here, we compare climate simulations of four warm interglacials at Marine Isotope Stages (MISs) 1 (9 ka), 5e (127 ka), 11c (409 ka) and 31 (1072 ka) with new proxy climate data recovered from Lake El'gygytgyn, NE Russia. Climate reconstructions of the mean temperature of the warmest month (MTWM) indicate conditions up to 0.4, 2.1, 0.5 and 3.1 °C warmer than today during MIS 1, 5e, 11c and 31, respectively. While the climate model captures much of the observed warming during each interglacial, largely in response to boreal summer (JJA) orbital forcing, the extraordinary warmth of MIS 11c compared to the other interglacials in the Lake El'gygytgyn temperature proxy reconstructions remains difficult to explain. To deconvolve the contribution of multiple influences on interglacial warming at Lake El'gygytgyn, we isolated the influence of vegetation, sea ice and circum-Arctic land ice feedbacks on the modeled climate of the Beringian interior. Simulations accounting for climate–vegetation–land-surface feedbacks during all four interglacials show expanding boreal forest cover with increasing summer insolation intensity. A deglaciated Greenland is shown to have a minimal effect on northeast Asian temperature during the warmth of stages 11c and 31 (Melles et al., 2012). A prescribed enhancement of oceanic heat transport into the Arctic Ocean does have some effect on Lake El'gygytgyn's regional climate, but the exceptional warmth of MIS l1c remains enigmatic compared to the modest orbital and greenhouse gas forcing during that interglacial."
Extract: "The timing of significant warming in the circum-Arctic can be linked to major deglaciation events in Antarctica, demonstrating possible interhemispheric linkages between the Arctic and Antarctic climate on glacial–interglacial timescales, which have yet to be explained."
&
The following link leads to the University of Alaska Fairbank's website focused on Lake Elgygytgn research, and the extract following the link is from an article Posted on February 4th, 2014 by Laura Nielsen on "Inter-hemispheric climate coupling". The extract emphasizes that in the paleo-past the Antarctic generally responded more quickly to orbital induced solar insolation variations, and that repeatedly paleo-collapses of the WAIS resulted in subsequent Arctic amplification, due both to changes in ocean currents, and to increases in sea level pushing more warm Pacific water through the Bering St. into the Arctic Ocean. If the WAIS collapses this century, we may soon see a marked increase in Arctic amplification:
Title: "Inter-hemispheric climate coupling"
https://frontierscientists.com/2014/02/inter-hemispheric-climate-coupling/Extract: "
Antarctica and the ArcticClimate at the North and South pole are connected. Sediment records from Antarctica show that the West Antarctic ice sheet melted at various times in history. Following many of those events, the Arctic warmed. These recurring intervals of paired warming show that climate in the two hemispheres is linked – it’s called inter-hemispheric climate coupling.
“When the West Antarctic ice sheet pulls back we see a corresponding warmth in the high lattitudes again, probably affecting the size of the Greenland ice sheet with major implications for changes in sea level,” says Julie Brigham-Grette. “Our results mesh with what glaciologists are seeing today. Seven of the 12 major ice shelves around the Antarctic are melting or are gone. We suspect the tipping point for the gradual de-glaciation of Greenland and the Arctic may be lower than glaciologists once thought.”
Complex systemsEarth is a complicated place. We can’t explain past warming using only orbital dynamics or levels of Carbon Dioxide. Scientists affiliated with the project outlined some past events that might explain the rapid warming the sediment records show occurred in both Antarctica and the Arctic around similar times.
When you imagine Antarctica, the picture includes large ice shelves that hang off the rocky edge of the ice-covered continent. Normally that ice keeps nearby ocean water very cold. The cold water travels along currents toward the north Pacific where it wells up to the surface. Ocean circulation can be affected, though. If Antarctic ice sheets disintegrate or melt away, they no longer enforce cold water currents that journey to the Arctic. Instead, surface ocean waters in the Arctic become warmer.
When Antarctica’s ice sheets disintegrate the ocean gains more water and sea levels rise globally. The Bering Strait usually restricts how much warm surface water approaches the Arctic from the south, but higher sea levels would mean warm surface water didn’t have to squeeze through such a narrow space, letting more warm water past the Bering Strait into the Arctic Ocean.
Either way, a warmer ocean means higher temperatures and more rainfall for the Arctic, which impacts paleoclimatology and sea ice history. Grasping the climate connections between the hemispheres gives us insight into our near future."
&
As I have noted that the MIS 11 (Holsteinian) era is particularly relevant to possible future scenarios for the impact of climate change, I provide the following paleo reference:
Florence Chen et al (2014), "Refining Estimates of Polar Ice Volumes during the MIS11 Interglacial Using Sea Level Records from South Africa", Journal of Climate,
https://doi.org/10.1175/JCLI-D-14-00282.1http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00282.1http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-14-00282.1Abstract: "Peak eustatic sea level (ESL), or minimum ice volume, during the protracted marine isotope stage 11 (MIS11) interglacial at ~420 ka remains a matter of contention. A recent study of high-stand markers of MIS11 age from the tectonically stable southern coast of South Africa estimated a peak ESL of 13 m. The present study refines this estimate by taking into account both the uncertainty in the correction for glacial isostatic adjustment (GIA) and the geographic variability of sea level change following polar ice sheet collapse. In regard to the latter, the authors demonstrate, using gravitationally self-consistent numerical predictions of postglacial sea level change, that rapid melting from any of the three major polar ice sheets (West Antarctic, Greenland, or East Antarctic) will lead to a local sea level rise in southern South Africa that is 15%–20% higher than the eustatic sea level rise associated with the ice sheet collapse. Taking this amplification and a range of possible GIA corrections into account and assuming that the tectonic correction applied in the earlier study is correct, the authors revise downward the estimate of peak ESL during MIS11 to 8–11.5 m."