Ocean Rises, Science Sinks – Watts Up With That?

Guest Post by Willis Eschenbach

Ever wondered how a tiny rise in sea level—let’s say, the aquatic equivalent of topping up your birdbath—might be responsible for frigid winters rampaging through East Asia? No? Well, Nature Communications thinks you should, in an article yclept “Intensification of extreme cold events in East Asia in response to global mean sea-level rise“.

Here’s their premise, as bold as a flashing warning sign on your grandma’s thermostat: A global mean sea-level rise of 15–30 cm can intensify extreme cold events in East Asia, thanks to a retooled atmospheric circulatory engine, weakening westerlies, and powered-up blocking episodes.

Mind you, this is not about that old chestnut, Arctic amplification or vanishing sea ice; it’s the earth-modeling equivalent of arguing that rearranging the living room somehow makes next winter’s snow deeper.

So, how did we get here?

I did what any skeptical denizen of the scientific peanut gallery would do: pondered their use of the NorESM1-F Earth System Model, the chosen oracle of this saga. Picture it—a whopping 2200-year sensitivity experiment, climate dials set to “controlled conditions” (CO₂ steady at 400 ppm, as if the atmosphere were on cruise control). The researchers periodically poured another cupful into the global ocean, then waited to see if the weather started shivering in East Asia.

Their definition of “cold extreme”? Days below the 10th percentile surface air temperature. Their measure of blocking? A reversal index for 500 hPa geopotential height (if that sounds like NASA-jargon, it is—think traffic jams in the jet stream).

Transparency, you say? Sure, you can sift through their supplementary files and simulated archive in the EU’s Zenodo repository—model outputs in glorious bulk if you’re inclined to lose weeks in NetCDF purgatory.

But empirical data? Not a sausage. Not one single lonely observation. No time series to ground these flights of model fancy.

Let’s hit pause for a moment and return to ugly reality. Does historical sea-level rise correlate with nasty winter chills in East Asia?

Not per the record: since 1900, global sea level crept up around 20 cm, but there’s no independent demonstration that this correlated with actual cold extremes in the region. In fact, most climate analyses emphasize local, not global, fingerprints.

So here’s my summary of my critique of the study, in three acts:

1. Single Model Dependency
The findings are entirely shackled to NorESM1-F—a ponderous climate engine whose output is only as good as its assumptions. There’s no check against real-world circulation, no multi-model brawl for robustness. It’s as if we rated steak quality by asking only one vegetarian chef.

2. Plausibility—Or The Lack Thereof
A the end of the last glaciation, sea levels rose by on the order of 120 meters (12,000 cm). Is it physically plausible that nudging the average sea level upward by a mere twenty centimeters will scramble global-scale atmospheric machinery? As someone who enjoys a good weather metaphor, I say: that’s like expecting the Second Law of Thermodynamics to take requests from the audience.

And then there’s blocking dynamics. In the real world? Much larger effects emerge from Arctic warming and sea ice loss than from sea-level twitchiness. Moreover, the study does not exclude confounders like SST changes, sea ice variability, or those slow-moving decadal ocean cycles that usually run this show.

3. Where Are the Comparisons To Reality?
A single climate model struts across the stage, unopposed. No ERA-Interim, no NCEP/NCAR, no HadCRUT temperature data, no observational counterpoint.

Let’s talk logic. The paper’s “nonlinear” threshold—cold events only spring loose above a 0.625m sea-level scenario—seems arbitrary, and it’s totally unsupported by observational reality. Real-world cold spikes in East Asia have been diagnosed as the products of Arctic heat, sea ice droughts, and the peculiar ballet of oceanic cycles, not bathtub-level adjustments.

No primary source—none—shows that sub-meter global mean sea-level rise is a puppetmaster for blocking frequency or icy East Asian blasts. All such claims hitch their wagon to untested numerical projections, idealized boundary conditions, and a climate model’s fever dreams.

The logic that a shallow sea-level rise reorganizes planetary wind and weather systems?

Dramatic pause …

No. Just no.

So what does this mean?

If you’re poised to rewrite winter preparedness handbooks based on sea-level forecasts, put that pen down. The dominant factors in real-world cold extremes—Arctic temperature, sea ice, ocean temperatures—remain unaffected by the aquatic inchworm pace of mean sea-level rise.

A final thought. Sea level has gone up about 20 cm in the last 125 years. If the cold weather only starts with an additional 62.5 cm of sea level rise, that means it will begin in … divide by pi, carry the 3 …

…

… the year 2415.

Be very afraid …

As always in science, I’m open to correction—if someone drags an empirical time series from the basement that links 20 cm of GMSL with bitter Februarys in Beijing, I’ll eat my galoshes.

But for now? File this under “Climate Mythmaking: The Model Show.”

w.

You Know The Drill: When you comment, quote the exact words you’re discussing. I can’t defend your interpretation of what I write.