Climate crisis news: Tipping point in the Arctic, Atlantic circulation, drying planet

Climate scientists, especially those who worry more than climate change Obamiacs like Michael Mann and Katharine Hayhoe, talk regularly about "tipping points."

And, in the past year, per the headline, we may have hit one of those.

The Arctic last year became a net carbon emitter. Remember that "carbon" in these discussions includes other greenhouse gases besides carbon dioxide. In this case, of course, it includes methane releases from a warming tundra.

This probably is NOT a one-off. I'm sure the climate science world will be giving this more scrutiny over the next year or so. 

The study notes that increased Arctic wildfires are removing more and more cover from tundra areas, helping accelerate the methane release.

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Second?

The Atlantic Meridional Overturning Circulation, a hot-cold deepwater conveyor belt, is showing definite if modest signs of weakening, as more glacier melt from Greenland screws with the northern end of the deep waters beneath the Gulf Stream.

Per a follow-up piece at Yale Climate, how much of a worry is this? More than you might think, unless you know a fair amount about what all is involved, including that this will affect global ocean currents, not just the North Atlantic. And, yes, that includes a tipping point on moving from weakening to collapse. Per links inside the piece? It could be just 30 years or so, a bit past midcentury. It may be longer. (Bob Henson and Jeff Masters, authors of both pieces, say early next century.) But, per the early possible date? It could be in OUR lifetimes, not the stereotypical children's or grandchildren's.

Northern Europe will bear the brunt of the problem. But, per some modeling, and what I said about "global"? It will affect everybody:

By the time the collapse was done, the impacts included Arctic sea ice spreading far into the North Atlantic and wet and dry seasons trading places in the Amazon. The average February temperature plummeted by a bone-chilling 15 degrees Celsius (27 degrees Fahrenheit) in London and by around 3°C (5°F) across the mid-Mississippi Valley of the United States.

There you go. Worse than the Little Ice Age in northwestern Europe. Pre-Industrial Revolution, or late Little Ice Age, in the heartland of the US.

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Already, other large scale climate effects have made three-quarters of the planet's land area drier. Yale Climate noted that an AMOC collapse would flip wet and dry seasons in Brazil. It's also one of the worst places for increasing dryness, and the ongoing deforestation doesn't help.