The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

A shutdown of the conveyor belt is not a scenario that any credible scientists worry about on any human timescale. But a slowdown is another matter. Already, climate change has depressed the velocity of the Gulf Stream by as much as 15 percent, a development that scientists call “an unprecedented event in the past millennium,” believed to be one reason the sea-level rise along the East Coast of the United States is dramatically higher than elsewhere in the world. And in 2018, two major papers triggered a new wave of concern over the conveyor belt, technically called Atlantic Meridional Overturning Circulation, which was found to be moving at its slowest rate in at least 1,500 years. This had happened about a hundred years ahead of the schedule of even alarmed scientists and marked what the climate scientist Michael Mann called, ominously, a “tipping point.” Further change, of course, is to come: the transformation of the ocean by warming making these unknown waters doubly unknowable, remodeling the planet’s seas before we ever were able to discover their depths and all the life submerged there.