Not Just Another “Super” El Niño

[Graeme Taylor]

FYI:
https://drtomharris.substack.com/p/not-just-another-super-el-nino-article

[John Nissen]

Thanks, Graeme.

The implications for steric sea level rise (the result of ocean expansion) are interesting.  I told Jan he was wrong that the oceans would emit heat: they are absorbing heat at a colossal rate.  

"Furthermore, global ocean heat uptake jumped by a staggering 23 zettajoules (ZJ) in 2025 alone. For context, 23 ZJ is roughly 200 times the total annual electricity generation of the entire human race. The 2025 ocean heat uptake represents an eight-fold increase over the 1958–1985 annual mean baseline (~2.9 ZJ)."

23 zettajoules corresponds to 0.7288 petawatts, or 1.43 W/m2.  CO2 heating is just over 2 W/m2; so most of it is going into heating the oceans.  

But there's an implication on sea level rise.  Steric sea level rise is closely proportional to ocean heat uptake.  So the rate of SLR will have increased 8-fold since the 1958-1985 baseline (around 2 cm per decade).  This is far worse than I feared; and promises as much as a metre of steric sea level rise by the time global warming has reached 3C in around 2070 (as extrapolated from current heating rate).  This is alone a strong argument for SAI global cooling, to follow SAI Arctic cooling which is unbelievably urgent (to halt its warming and meltdown, while still just about feasible).

Cheers, John

On Wed, Jun 17, 2026 at 9:22 AM Graeme Taylor <gra...@bestfutures.org> wrote:

FYI:
https://drtomharris.substack.com/p/not-just-another-super-el-nino-article

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[John Nissen]

Hi Graeme,

Clive has just pointed out that I should read to the end.  The last three paragraphs [1] spell out the real danger from the "great tipping elements" including the underlined.  These are all affected by Arctic temperature and continued AMOC strength in the case of the Amazon.  They have already reached a point of irreversibility where only immediate SAI deployment has a chance of lowering the Arctic temperature to prevent their inevitable collapse, directly or indirectly, sooner or later.  Lowering the Arctic temperature involves countering the heating power with even greater cooling power, which only SAI can do.  And that heating power to be countered is growing rapidly - even more rapidly with the Super El Nino in prospect.  There is no time to lose.

Governments need to get together to prepare for a rapid ramp-up of SAI to full strength, with the intensity and urgency of the Manhattan Project though the enemy is of a different class.

Cheers, John

[1] https://drtomharris.substack.com/p/not-just-another-super-el-nino-article

Following that, 2027 will likely soar to between 1.7°C and 1.8°C for the calendar year average. It will certainly be hotter than whatever 2026 delivers, since the peak SAT temperatures lag the ocean temperature extremes. When the system settles in 2028–2030, our new “cool” baseline will likely hover around 1.55°C to 1.7°C—leaving us perfectly positioned so that the subsequent El Niño introduces the first full calendar year at +2.0°C, depending on when it emerges. Permanently passing 2°C next decade now seems unavoidable.

The planetary impacts locked into the backend of this decade will be severe; there is simply too much thermal energy accumulated in the system for any other outcome. This places the planet squarely in the danger zone for a number of the great tipping elements including the West Antarctic and Greenland Ice Sheets, Boreal Permafrost abrupt thawing, Ocean Current disruption and Amazon collapse.

We can only hope that these upcoming systemic shocks finally jolt global leadership and the voting public into treating the crisis with the structural seriousness it demands.

[Tom Goreau]

Point of clarification. I think you misunderstood Jan’s point. He was not saying that the ocean was emitting net heat  to the atmosphere NOW, but that it would start to do so after surface temperature was reduced by successful SAI cooling.

 

Melting of ice freshens surface waters and adds to volume expansion:

Munk, W., 2003. Ocean freshening, sea level rising. Science, 300(5628), pp.2041-2043.

 

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[Alan Kerstein]

This suggests that there is some optimum extent of SAI deployment, with each increment providing net benefit until a point at which further increments cause net harm.  Therefore it seems worthwhile to develop some rough estimate of the shape of this (positive or negative) marginal benefit versus extent of deployment curve in order to scope out the maximum achievable long-term net benefit of SAI. This might go beyond the bounds of strict scientific validity but policy decisions often must be made on the basis of the best available information, however inadequate.

Alan

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[PR CARTER]

Any ideas on this-I can find nothing

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From: "Alan Kerstein" <alan.k...@gmail.com>
To: "Thomas Goreau" <gor...@globalcoral.org>
Cc: "John Nissen" <johnnis...@gmail.com>, "Graeme Taylor" <gra...@bestfutures.org>, "HPAC" <healthy-planet-...@googlegroups.com>, "Jan Umsonst" <j.o.u...@gmail.com>, "Planetary Restoration" <planetary-...@googlegroups.com>
Sent: Wednesday, June 17, 2026 4:29:31 PM

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Director Climate Emergency Institute
IPCC expert reviewer
Co-author2018 Unprecedented Crime: Climate Science Denial and Game Changers for Survival

[John Nissen]

Hi Peter,

I don't think there is any risk of overcooling by SAI, as Jan suggests.  If the sea temperature in the top few metres of the north North Atlantic can be lowered to what it was a few decades ago, that should probably be enough to allow the Arctic to be refrozen.  Researchers on SAI are confident that injection at 50 or 60 degrees North can lower the Arctic temperature such as to halt the tipping processes and start refreezing the Arctic [1].  Note that some cooling actually occurs at lower latitudes than the injection latitude due to variability in the direction of stratospheric winds which tend to have a northerly component due to Brewer-Dobson circulation.

Cheers, John

[1] Smith et al. (2022)

A subpolar-focused stratospheric aerosol injection deployment scenario

https://iopscience.iop.org/article/10.1088/2515-7620/ac8cd3