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Comment by technocratius | Hacker News Reader

If I understand correctly it's mainly the effect of the moon's nodal precession [0] in combination with climate-change induced rising sea levels.

I am curious about its effects on non-US coastal cities as well (also personally, as I happen to live in one). Hopefully it will be repeated/extended in the future.

[0] https://en.m.wikipedia.org/wiki/Lunar_precession#Nodal_prece...

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> If I understand correctly it's mainly the effect of the moon's nodal precession [0] in combination with climate-change induced rising sea levels.

Sea level rise since 1995 has averaged 3.4 mm per year[1].

Is there an expectation that this will accelerate significantly? or is a change in 30mm expected to contribute significantly to flooding?

[1]: https://climate.nasa.gov/vital-signs/sea-level/

As the average temperature increases, it seems reasonable to expect the rate of melting, thus sea level rise, increase. Add to that highly nonlinear effects like the "clathrate gun", and a continuing linear increase in sea level seems highly non-obvious

Warm temps push more water to the atmosphere so its not linear in terms of sea level rise. You'd expect more ice to melt but you might also see more snow, glaciers growing.

Nope, I'd expect the current trend of glaciers and icecaps melting to continue or accelerate. And for rainy seasons to get more severe. As they have been.

But this is talking about 2030, not 2100. I guess the question is, if sea level rise stopped completely today, would there be no problem in 2030?

Why is that the question? Is there any evidence to suggest that the sea level will completely stop rising today?

> Why is that the question?

Because the article is about 2030 and unless the rate of sea level rise accelerates significantly in 9 years that means sea level will be about 36 mm higher in 9 years. And it is hard for me to see how 36 mm higher sea level will flood much of anything, so it seems that the moon wobble will do most of the heavy lifting if we compare the situation today to the predicted situation in 2030.

> Is there any evidence to suggest that the sea level will completely stop rising today?

No.

Consider the mass of 36mm integrated over the area of our oceans. That mass has been converted from solid to liquid. What was once rigid is now a veritable loose canon. The effect of tidal forces is to concentrate that mass towards the moon -- so the amplitude of flooding caused by a lunar wobble should be expected to be greater with more liquid water available to participate. I wouldn't be so quick to dismiss the impact of that rise.

It seems like a lot?

Just first google result 2* C warming would be ~10cm and reading the effects of that sounds pretty bad.

https://www.vox.com/energy-and-environment/2018/1/19/1690840...

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