Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous ...

• Main Authors: Hansen, James E., Sato, Makiko H., Hearty, Paul, Ruedy, Reto, Kelley, Maxwell, Masson-Delmotte, Valerie, Russell, Gary, Tselioudis, George, Cao, Junji, Rignot, Eric, Velicogna, Isabella, Tormey, Blair, Donovan, Bailey, Kandiano, Evgeniya, Von Schuckmann, Karina, Kharecha, Pushker A., LeGrande, Allegra N., Bauer, Michael P., Lo, Kwok-Wai
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2016
• Subjects: Paleoclimatology; Ocean temperature; Sea level; Ice sheets; Severe storms; Climatic changes; Atmosphere; Greenland; Southern Ocean; Antarc*; Antarctica; Ice Sheet; Ice Shelf; North Atlantic
• Online Access: https://dx.doi.org/10.7916/d8t153j4; https://academiccommons.columbia.edu/doi/10.7916/D8T153J4

We use numerical climate simulations, paleoclimate data, and modern observations to study the effect of growing ice melt from Antarctica and Greenland. Meltwater tends to stabilize the ocean column, inducing amplifying feedbacks that increase subsurface ocean warming and ice shelf melting. Cold meltwater and induced dynamical effects cause ocean surface cooling in the Southern Ocean and North Atlantic, thus increasing Earth's energy imbalance and heat flux into most of the global ocean's surface. Southern Ocean surface cooling, while lower latitudes are warming, increases precipitation on the Southern Ocean, increasing ocean stratification, slowing deepwater formation, and increasing ice sheet mass loss. These feedbacks make ice sheets in contact with the ocean vulnerable to accelerating disintegration. We hypothesize that ice mass loss from the most vulnerable ice, sufficient to raise sea level several meters, is better approximated as exponential than by a more linear response. Doubling times of 10, 20 or ...