PBS Terra explains 'The AMOC Might Be WAY More Unstable Than We Thought...Here's Why'

For today's evergreen entry that I can share next month, which is also next year, I'm revisiting the topic of 'Weathered' on PBS asks 'Is This Crucial Ocean Current About to COLLAPSE?' Watch as PBS Terra explains The AMOC Might Be WAY More Unstable Than We Thought...Here's Why.

There is a mysterious cold blob in the North Atlantic that could be a warning sign that the largest heat transfer system on the planet, the AMOC, is on the brink of collapse. But it turns out that the AMOC’s collapse is a highly debated topic among scientists – climate models are inconsistent and there isn’t enough observational data to determine a trend. So, perhaps the answer to understand a possible AMOC collapse is to go back in time.

In this episode, we talk to three paleoclimate experts who look at the Earth’s past climate and find some really shocking things about the AMOC’s past behavior. And it turns out that the mysterious cold blob may actually be a bigger deal than we realize…

I'm a paleontologist who has researched late Pleistocene climate, so I approve of this approach. As I wrote in Prehistoric lions of Eurasia and North America for World Lion Day 2022, "one of the points of paleontology is to learn from the past and apply the knowledge gained to the present." That's even more true of paleoclimatology.

Like last time, I'm recycling the rest of my response from Susan Lozier at TED asks 'Is Climate Change Slowing Down the Ocean?' and PBS Terra asks 'Is Earth's Largest Heat Transfer Really Shutting Down?'

This is not a new concern, as Al Gore described it in "An Inconvenient Truth." I asked about it specifically in the worksheet I used in one of my classes, which I reproduced in Hot (not): a cold blast from the past along with an answer.

What is the likely effect of the melting of the Greenland ice cap on ocean circulation and global climate?

In the movie, the idea is that the release of meltwater from a large glacial lake diluted the Gulf Stream, causing the water to become less dense and unable to sink to the bottom of the ocean off Greenland, jamming up the global thermohaline circulation and sending the planet back into an ice age for another thousand years. An analogous melt of water from the Greenland icecap, which is beginning to happen, would do much the same thing, slowing ocean circulation and cooling Europe. Both of those are indeed taking place.

The movie came out seventeen [now eighteen] years ago and I wrote the above more than ten years ago. It's not as if we weren't warned.

Speaking of which, PBS Terra listed the Greenland ice sheet and the AMOC (Atlantic Meridional Overturning Circulation) last September in PBS Terra asks 'What Will Earth Look Like When These 6 Tipping Points Hit?' I'm reusing my reaction from that post as well.

Watching all that reminds me that none of these threats are new, so my reaction isn't either.

First, welcome to the 400 ppm world. Second, are you scared enough by climate change? My readers should be.

Hey, I'm an environmentalist; I recycle.

I'm not the only one recycling a subject; PBS Terra's previous video is the latest in a series that began with PBS examines the risks from a major earthquake in the Pacific Northwest and continued with PBS Terra explains 'Here's EXACTLY What to Do When the Next Megaquake Hits: Cascadia Subduction Zone' and PBS Terra asks 'What's the ONE THING You Can Do To Survive a Tsunami?' I will almost certainly cover that in a future entry, but I already have my own series of holiday and year-end retrospective posts planned through the end of the year, beginning with a celebration of the Winter Solstice/Yule. Stay tuned.