Space lasers reveal oceans rising faster than ever

[John Nissen]

Space lasers reveal oceans rising faster than ever | ScienceDaily https://share.google/UqrVIgqfNPphITuQi 

[John Nissen]

Hi John,

The paper referred to here [1] makes a point about the acceleration of barystatic sea level rise: the rise due to added mass as opposed to steric SLR which is due to ocean expansion.  The barystatic SLR is now dominating, and it is accelerating.  In a recent letter, published in the FT, I said we could expect half a metre of SLR (barystatic) from Greenland this century, with at least as much again from Antarctica (0.6m was one estimate).  

If steric SLR follows temperature, then we can expect about 1.4m from expansion on the current trajectory of unabated global warming: 0.20m in the last century, averaging 0.3C extrapolates to 1.4m this century with average say 2.1C*,

Without intervention, the likely SLR this century could be around 2.5m, if we put all the estimates together.  The cost by the end of the century could run into trillions of dollars per year, whereas, with SAI to refreeze the Arctic, cool Antarctica and lower the global temperature, the cost per year by the end of the century would be relatively trivial.  As for the cost of the SAI, it would run into tens of billions of dollars per year, which is a very small price to pay for avoiding a cost of trillions per year by the end of the century.

With your backing, I would like to quote the 2.5m figure in a submission to the EU on protecting the Arctic. And I look forward to your support for SAI, simply on a cost basis, assuming you accept my estimates as being not too unreasonable.  The other benefits from SAI could be even greater; but that is another story.

Cheers, John

*2.1C is probably conservative with 2.0C being likely by 2040 and 4.0C likely by 2100 if global warming continues to accelerate.

[1] Space lasers reveal oceans rising faster than ever

https://www.sciencedaily.com/releases/2026/02/260222092321.htm

Summary

A new 30-year analysis reveals that melting land ice is now the main force behind rising global sea levels. Researchers discovered that oceans rose about 90 millimeters since 1993, with most of the increase coming from added water mass rather than just warming expansion. Ice loss from Greenland and mountain glaciers accounts for the vast majority of this gain. Even more concerning, the rate of sea-level rise is accelerating.