Ocean surface temperatures.

A historic visualization of sea surface temperatures by NASA. Recent data showing a surge ocean temperatures, writes McKibben, "has scientists somewhat perplexed and considerably more frightened."

(Image: NASA)

Big Trouble in the Deep: World's Oceans Are Now Heating Up Very, Very, Very Fast

Remember, people, this is an experiment we haven’t run before, and the test tube we’re using is the whole planet.

Something very troubling is happening on and under the 70 percent of the planet’s surface covered by salt water. We pay far more attention to the air temperature, because we can feel it (and there’s lots to pay attention to, with record temps across Asia, Canada and the Pacific Northwest) but the truly scary numbers from this spring are showing up in the ocean.

ocean heat temperature data in chart and visual form(Graph/Data: via Climate Reanalyzer.org/University of Maine)

If you look at the top chart above, you can see “anomaly” defined. That’s the averaged surface temperature of the earth’s oceans, and beginning in mid-March it was suddenly very much hotter than we’ve measured before. In big datasets for big phenomena, change should be small—that’s how statistics work, and that’s why the rest of the graph looks like a plate of spaghetti. That big wide open gap up there between 2023 and the next hottest year (2016) is the kind of thing that freaks scientists out because they’re not quite sure what it means. Except trouble.

The magnitude of this jump has scientists somewhat perplexed and considerably more frightened—as the BBC pointed out, the numbers are extreme.

In March, sea surface temperatures off the east coast of North America were as much as 13.8C higher than the 1981-2011 average.
"It's not yet well established, why such a rapid change, and such a huge change is happening," said Karina Von Schuckmann, the lead author of the new study and an oceanographer at the research group Mercator Ocean International.

One factor at play is that seagoing vessels have been rapidly phasing out their use of “bunker fuel,” the literal bottom-of-the-barrel tarry sludge that ships have generally burned because it is very very cheap and because they are…out at sea. Research indicated that the pollution from this stuff was blowing back to port and damaging humans, so as Ryan Cooper reports it is being replaced with cleaner fuel. Big enviro win, except that the aerosols in the choking exhaust of those ships (the stuff coming out the smoke stack) helped seed clouds as it trailed out across the main shipping routes; the air is now clearer on those routes, and hence more sunlight gets through to the ocean.

That big wide open gap up there between 2023 and the next hottest year (2016) is the kind of thing that freaks scientists out because they’re not quite sure what it means. Except trouble.

But in a deeper sense, the oceans just seem to be heating very very fast now. A little-noticed recent study headed by Katrina von Schuckmann found that “over the past 15 years, the Earth has accumulated almost as much heat as it did in the previous 45 years,” and that 89 percent of that heat has ended up in the seas. That would be terrifying on its own, but coming right now it’s even scarier. That’s because, after six years dipping in and out of La Nina cooling cycles, the earth seems about to enter a strong El Nino phase, with hot water in the Pacific. El Nino heat on top of already record warm oceans will equal—well, havoc, but of exactly what variety can’t be predicted.

And the ‘can’t be predicted’ part is the real problem. Remember, people, this is an experiment we haven’t run before, and the test tube we’re using is the whole planet. Lots of things will happen: maybe the Beaufort Gyre will release a whole lot of freshwater into the North Atlantic, further disrupting the already weakened Gulf Stream. I bet you hadn’t been worrying about the Beaufort gyre, but a new study last week… Or maybe there will be more of the Midwest drought currently forcing farmers to abandon wheat crops at a record rate. Or ocean oxygen levels will keep falling, putting pressure on lots of species (except jellyfish).

Some things we can say with near certainty: the World Meteorological Organization predicted today that there was a 98 percent chance that sometime during this El Nino run the world will set a new annual temperature record. (I’ve been guessing 2024, but the odds that 2023 might break the all-time record set in 2016 are rising by the day and are currently about one in four). There’s a very good chance, in fact, that at least for a year we will go past the 1.5 Celsius level that Paris set as the mark we should move heaven and earth to avoid. We haven’t moved heaven and earth—we budged Joe Manchin very slightly, though he’s now pushing back—and so we didn’t avoid it. Now what?

Now we have to organize as never before. This havoc, whatever form it takes, will produce pressure on our political and economic systems to do something. The oil industry will be trying to make sure that pressure is converted into yet more public dollars for carbon capture so they can go on burning coal and gas (check out this excellent summary of this particular scam from Food and Water Watch, and this NPR report on what happens when carbon pipelines rupture and suck out all the air).

Now we have to organize as never before.

So the rest of us better be prepared to give one last vigorous push to the clean energy project. As prices for the silicon in solar panels keep falling, the convergence of political pressure and economic opportunity offers the world one last good chance of—not stopping global warming, too late for that. A new National Renewable Energy Lab study underlines the fact that this is our cheapest, fastest option; a new Nature Conservancy study shows it will take even less land than we used to fear. But maybe stopping it short of cutting civilizations off at the knees. That’s what we’re playing for, and this stretch of hot weather is going to be our last best chance.

© 2022 Bill McKibben