Marine Ice-cliff Instability

Eric Holthaus describes research aimed at understanding how quickly sea levels could rise.

The glaciers [Pine Island and Thwaites] are two of the largest and fastest-melting in Antarctica. Together, they act as a plug holding back enough ice to pour 11 feet of sea-level rise into the world’s oceans — an amount that would submerge every coastal city on the planet.

A wholesale collapse of Pine Island and Thwaites would set off a catastrophe. Giant icebergs would stream away from Antarctica like a parade of frozen soldiers. All over the world, high tides would creep higher, slowly burying every shoreline on the planet, flooding coastal cities and creating hundreds of millions of climate refugees.

All this could play out in a mere 20 to 50 years — much too quickly for humanity to adapt.

Update (June 10, 2018):  Peter Clark discusses updates to the IPCC projections on sea level rise.

Update (February 4, 2019):  Robert Hunziker cites a study with a surprising discovery in Antarctica.

The new NASA study, utilizing IceBridge, shows a surprising loss of 14B tons of ice in only three years from the Thwaites Glacier, where a humongous hole lurks beneath the glacier’s icy/snowy surface, a massive cavity nearly the size of NYC but hidden within the core of the ice sheet.

Update (February 22, 2019):  Robert Hunziker has bad news from Antarctica.

According to NASA: "East Antarctica has the potential to reshape coastlines around the world through sea level rise, but scientists have long considered it more stable than its neighbor, West Antarctica. Now, new detailed NASA maps of ice velocity and elevation show that a group of glaciers spanning one-eighth of East Antarctica’s coast have begun to lose ice over the past decade, hinting at widespread changes in the ocean."

Update (January 28, 2020):  Robert Hunziker follows up on the news about Thwaites.

Update (February 5, 2020):  The faster than expected melting of Thwaites Glacier will eventually produce a 10 foot sea level rise by itself.