‘There’s no scenario that stops sea level rise in this century,’ dire U.N. climate report warns (September 2019)

The new Special Report on the Ocean and Cryosphere in a Changing Climate from the Intergovernmental Panel on Climate Change (IPCC), comes during a week when the world is fixated on what many now call the climate crisis. The planet has already warmed 1°C since preindustrial times, and July was the hottest month in the modern record. The report stresses that the watery parts of the planet are already entering a new state. After 0.2 meters of sea level rise since the late 1800s, some coastal cities flood routinely during high tides. With the Arctic warming at double the global rate, sea ice is in rapid decline, causing severe disruption to Indigenous communities and wildlife. “There are changes in the ocean we can’t stop,” says Nerilie Abram, a report author and paleoclimatologist at Australian National University in Canberra.

Like all IPCC reports, this week’s assessment reflects only science submitted for publication, which means it is already out of date. In a study due out later this year, for example, a team led by Schuur estimated that the rapid collapse of some permafrost landscapes as they thaw could increase emissions from permafrost by 50%. Nor could the current report draw on next-generation climate models developed for the next major IPCC report, due in 2021. Most of those models forecast faster warming than their predecessors. Robert DeConto, a glaciologist at the University of Massachusetts in Amherst, calls their omission “a little bit frustrating. ” (Paul Voosen, staff writer who covers Earth and planetary science )