Antarctic tipping points for a multi-metre sea level rise

The West Antarctic Ice Sheet (WAIS), comprising more than two million cubic kilometres of ice, is under pressure from a warming climate, with scientists saying its break-up –– and an eventual global sea-level rise of 3–5 metres –– is not matter of if, but when.

The West Antarctic Peninsula is now the strongest-warming region on the planet, and WAIS glaciers are discharging ice at an accelerating rate

Recent studies, surveyed in this report, suggest that WAIS passed a tipping point for large-scale deglaciation decades ago.

This should not be surprising, because such an event was foreseen almost 50 years ago. In 1968, pioneer glacier researcher John Mercer predicted that the collapse of ice shelves along the Antarctic Peninsula could herald the loss of the ice sheet.

Read the Climate Code Red story - “Antarctic tipping points for a multi-metre sea level rise.”

The 'sword of Damocles' maybe the melting of the West Antarctic ice sheet

For half a century, climate scientists have seen the West Antarctic ice sheet, a remnant of the last ice age, as a sword of Damocles hanging over human civilization.

The great ice sheet, larger than Mexico, is thought to be potentially vulnerable to disintegration from a relatively small amount of global warming, and capable of raising the sea level by 12 feet or more should it break up. But researchers long assumed the worst effects would take hundreds — if not thousands — of years to occur.

Now, new research suggests the disaster scenario could play out much sooner.

Continued high emissions of heat-trapping gases could launch a disintegration of the ice sheet within decades, according to a study published Wednesday, heaving enough water into the ocean to raise the sea level as much as three feet by the end of this century.

Read Justin Gillis’s story in The New York Times - “Climate Model Predicts West Antarctic Ice Sheet Could Melt Rapidly.”