North Atlantic and sub-Antarctic Ocean temperatures: possible onset of a transient stadial cooling stage
The ice core glacial-interglacial record of the last 450 kyr (Cortese et al. Paleogeogr Paleoclimatol 22:4, 2007), development of cold ice meltwater regions at fringes of the Greenland and the West Antarctic ice sheets, and climate projections by Hansen et al. (Atmos Chem Phys 16:3761–3812, 2016), support a relation between ice sheet melting and the cooling of neighboring ocean zones by ice meltwater. Several factors lead to cooling of parts of the North Atlantic Ocean and adjacent lands, including the following: (A) a slowdown of the Atlantic meridional overturning circulation (AMOC); (B) flow of cold ice meltwater from the Greenland ice sheet into the North Atlantic Ocean; (C) undulation and weakening of the jet stream at the Arctic boundary due to a rise in temperature in the Arctic circle at twice the rate of warming at lower latitudes and the ice-water albedo flip. Penetration of Arctic-derived cold air masses southward through a weakened jet stream boundary ensues in extreme weather events in North America and Europe. The slowdown of the AMOC (Caesar et al. Nature 556:191–196, 2018; Praetorius Nat Clim Chang 5:475–480, 2018; Thornalley et al. Nature 556:227–230, 2018; Smeed et al. Geophys Res Lett 45(3):1527–1533, 2018) and growing cold ocean region (Rahmstorf et al. Nat Clim Chang 5:475–480, 2015) may herald the onset of a stadial event. A large-scale stadial event, possibly on the scale of the 8.3–8.2 kyr-old Laurentian melt event, or even the 12.9–11.7-kyr-old Younger Dryas stadial (Carlson Encycl Quat Sci 3:126–134, 2013), could ensue from advanced melting of both the Greenland ice sheet and the Antarctic ice sheet. A stadial would be succeeded by the resumption of warming driven by a continuing rise in greenhouse gas concentrations and amplifying feedback effects. These projections need to be examined vis-a-vis the continuous linear IPCC temperature rise models.
I am grateful to the reviewers for comprehensive in-depth comments and contributions to the manuscript. I thank Will Steffen for his comments. Brenda McAvoy has kindly proof read the paper. I thanks Prof James Hansen for permission to cite figures and John Wiley and Son for permission to cite Fig. 4.
- Canadell JG (2009) Super-size deposits of frozen carbon threat to climate change. Proc Am Assoc Adv Sci https://www.eurekalert.org/pub_releases/2009-06/gcp-sdo_1063009.php
- Cortese G, Abelmann A, Gersonde A (2007) The last five glacial-interglacial transitions: a high-resolution 450,000-year record from the sub-Antarctic Atlantic. Paleogeogr Paleoclimatol 22:4Google Scholar
- Easterbrook S (2014) We have to choose which future we want very soon. New IPCC Report (Part 6) Azimuth Project https://johncarlosbaez.wordpress.com/2014/04/16/what-does-the-new-ipcc-report-say-about-climate-change-part-6/
- Hansen J (2018) Climate change in a nutshell: the gathering storm. Earth Institute – Columbia University http://csas.ei.columbia.edu/2018/12/18/climate-change-in-a-nutshell-the-gathering-storm-2/
- Hansen J et al (2013) Climate sensitivity, sea level and atmospheric carbon dioxide. Philos Trans A Math Phys Eng Sci 371(2001)Google Scholar
- IPCC (2013) Two decades of the Atlantic meridional overturning circulation: anatomy, variations, extremes, prediction, and overcoming its limitations. https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00478.1
- IPCC (2015) Global Temperature Part 2: Future Projections http://climatesmartnetwork.org/2015/03/global-temperature-part-2-future-projections/
- IPCC AR5 WGI (2015) Chapter 12 global temperature part 2: future projections. http://climatesmartnetwork.org/2015/03/global-temperature-part-2-future-projections/
- NASA (2018) 2018 is only halfway over, but a troubling climate change trend is already apparent. https://mashable.com/article/global-warming-trend-nasa-charts/#VepvpgqlSaqk
- Rignot E et al (2011) Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophys Res Lett 38(5)Google Scholar
- Shepherd A et al. (The IMBIE team) (2018) Mass balance of the Antarctic ice sheet from 1992 to 2017. Nature 558: 219–222Google Scholar
- Weaver AJ et al (2012) Stability of the Atlantic meridional overturning circulation: a model inter-comparison. Geophys Res Lett 39(20)Google Scholar