Climate Collapse Could Happen Fast

So far this summer in America and many parts of the world has been marked by record heat, devastating once in a century or longer rainfall and other signs that the world's climate is relentlessly changing.   The Republican Party response: more denial and efforts to rescind spending on climate change issues and renewable energy. Indeed, many Republicans want to even slash spending for fixing America's crumbling infrastructure.  Yet, as a piece in The Atlantic reviews, we may be closing to tipping points where drastic climate change may be set in irreversible motion with cataclysmic consequences. Living on a tidal creek, I and others in the Hampton Roads area of Virginia know that sea level rise is real and is happening before our eyes, albeit slowly at the moment.   That could change if the Greenland and Antarctica ice sheets melt.   The refusal of so many to face reality is mind numbing.  Here are article excerpts:

Ever since some of the earliest projections of climate change were made back in the 1970s, they have been remarkably accurate at predicting the rate at which global temperatures would rise. For decades, climate change has proceeded at roughly the expected pace, says David Armstrong McKay, a climate scientist at the University of Exeter, in England. Its impacts, however, are accelerating—sometimes far faster than expected.

For a while, the consequences weren’t easily seen. They certainly are today. The Southwest is sweltering under a heat dome. Vermont saw a deluge of rain, its second 100-year storm in roughly a decade. Early July brought the hottest day globally since records began—a milestone surpassed again the following day. “For a long time, we were within the range of normal. And now we’re really not,” Allegra LeGrande, a physical-research scientist at Columbia University, told me. “And it has happened fast enough that people have a memory of it happening.”

In fact, a growing number of climate scientists now believe we may be careening toward so-called tipping points, where incremental steps along the same trajectory could push Earth’s systems into abrupt or irreversible change—leading to transformations that cannot be stopped even if emissions were suddenly halted. . . . If these thresholds are passed, some of global warming’s effects—like the thaw of permafrost or the loss of the world’s coral reefs—are likely to happen more quickly than expected. On the whole, however, the implications of blowing past these tipping points remain among climate change’s most consequential unknowns: We don’t really know when or how fast things will fall apart.

Some natural systems, if upended, could herald a restructuring of the world. Take the Thwaites Glacier in West Antarctica: It’s about the size of Florida, with a protruding ice shelf that impedes the glacier’s flow into the ocean. Although the ice shelf’s overall melt is slower than originally predicted, warm water is now eating away at it from below, causing deep cracks. At a certain point, that melt may progress enough to become self-sustaining, which would guarantee the glacier’s eventual collapse. How that plays out will help determine how much sea levels will rise—and thus the future of millions of people.

We may not even realize when we start passing points of no return—or if we already have. “It’s kind of like stepping into a minefield,” Armstrong McKay said. “We don’t want to find out where these things are by triggering them.”

Even before the climate gets to that point, we may face a dramatic uptick in climate-related disasters, says William Ripple, a distinguished professor of ecology at Oregon State University and the lead author of a recent commentary on the “risky feedback loops” connecting climate-driven systems. There’s a sense of awe—in the original meaning of inspiring terror or dread—at witnessing such sweeping changes play out across the landscape. “Many scientists knew these things would happen, but we’re taken aback by the severity of the major changes we’re seeing,” Ripple said.

Although it may be too late to avert some changes, others could still be staved off by limiting emissions. LeGrande said she worries that talking about tipping points may encourage people to think that any further action now is futile. In fact, the opposite is true, Ripple said. “Scientifically, everything we do to avoid even a tenth of a degree of temperature increase makes a huge difference.”