Every other Friday, the Outside/In team answers one listener question about the natural world.
This week, user @sjsk7242 asked us a question on Instagram: “What if the Gulf Stream shuts down?”
Outside/In’s Taylor Quimby and Nate Hegyi looked into it, and here’s what they learned.
Transcript
This has been edited for length and clarity
Nate Hegyi: Ooh, I’ve thought about this a lot actually Taylor.
Taylor Quimby: You have??
Nate Hegyi: Well yes, because I not-so-secretly love the movie The Day After Tomorrow, the climate change disaster film from 2004. It’s one of my favorites. And in it, the Gulf Stream “shuts down” and Europe, which is at a very high latitude, just freezes over. And I’ve always thought, if it did shut down… would northern Europe just turn into a tundra?
Taylor Quimby: Would there be an overnight ice age?
Nate Hegyi: I don’t know! I’m fascinated. What did you find out?
Taylor Quimby: OK. The Gulf Stream is a deep ocean current that runs up from the Gulf of Mexico, alongside the East coast of the US for a little bit, before veering across the Atlantic ocean towards Europe.
But what makes the Gulf Stream super important is it’s role in regulating temperatures.
So as you point out - if you pull up a map, you’ll see that London, England and Calgary, in Canada, are basically the same latitude.
Nate Hegyi: Right! And Calgary has very cold, long winters. England is kind of more like Seattle.
Taylor Quimby: And the reason is all that warm water brings lots of warm water, up from the Gulf Stream, over to Europe.
So if somebody did just turn it off like a faucet… things would definitely get very weird. There would be huge consequences for fishing and the shipping industry.
And to your point, Europe would get way, way colder. We’re talking two to ten degrees Celsius as you go further north from places like Germany into Scandinavia.
I will say, the good news is that the Gulf Stream is definitely not going to “shut down.”
Nate Hegyi: I thought I read a study recently that the chances of it shutting down in the next 100 years is quite high…
Taylor Quimby: Hmm, well hold that thought.
Alice Ren: The Gulf Stream totally disappearing is not going to happen, so you don't need to worry about it… but there are more nuanced changes in the amount of heat that will flow northward that may actually be important and that may impact us.
Taylor Quimby: So this is Alice Ren, she’s an oceanographer at the Woods Hole Oceanographic Institute. And she told me that scientists have been documenting changes to the Gulf Stream for some time.
Alice Ren: We found that it had warmed in the past 20 years by about one degree Celsius… The Gulf Stream is also shifting closer to the coast, only about ten kilometers in the past 20 years.
Taylor Quimby: But fears of a full “shut down” are very overblown. You see, the Gulf Stream is connected to this bigger cycle of ocean currents that sort of runs in a big clockwise circle around the Atlantic ocean. It’s called the Atlantic Meridional Overturning Circulation, or AMOC.
Nate Hegyi: AMOC! I’ve seen that acronym before.
Taylor Quimby: Yes! And there is a study that showed that the AMOC is weakening.
But after this study came out, a lot of news stories kind of conflated the AMOC and the Gulf Stream, and generally just exaggerated the findings of the study to somewhat apocalyptic levels.
Nate Hegyi: I read those news articles and I was thoroughly hooked by them.
Taylor Quimby: Well, it’s scary.
Nate Hegyi: It is scary! And, you know… The Day After Tomorrow.
Taylor Quimby: But the IPCC has had to make pains to clarify that, no,the gulf stream is not going to shut down. To me, the big takeaway is that our climate systems are interconnected in all of these surprising ways. And this is why we stopped saying “global warming” right? Because rising C02 emissions don’t have this linear effect on our temperature, they could lead to cooling in other parts of the world.
Nate Hegyi: Right. Global weirding.
Taylor Quimby: "Global weirding." I like that.
Nate Hegyi: I think that’s an accurate term for what’s happening.
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