[0hijinks]

>> ...we can see that, in less than two decades, Earth has tilted 31.5 inches as a result of pumping groundwater. This equates to .24 inches of sea level rise.

For those confused how they managed that geometric analysis, the sea level rise mentioned in the paper [1] is caused by groundwater depletion. The tilt is caused by groundwater depletion. The sea level rise is not caused by the tilt.

[1] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10...

[martinpw]

Figure 1 in the above paper packs a lot of interesting information: https://agupubs.onlinelibrary.wiley.com/cms/asset/d7c477fa-3...

One important factor shown there is that dams hold back water on land, so act to decrease sea levels. It is not as big an effect as groundwater depletion, but is significant (around half as much).

The net effect of these two is much less than the other factors causing sea level rise (melting land ice) - looks like around 10% of total sea level rise comes from groundwater depletion+dams combined.

[metalman]

here's the problem with dams filling up and offseting ocean rise, amost all of the potential large dams, have been built and are full now, and that offset has masked some ocean rise, which is now accelerating, but all of the "planning" ,climate mitigation policy, treatys, etcerlalala, has been working with the wrong numbers. the wild card is changes in salinity and temperature shutting down the main thermo transfer currents at each pole, setting off deap ocean warming and expansion. not good.

[chongli]

Not to mention that inches are not a measure of angle, they’re a measure of length. I would prefer a proper measure of angle such as arcseconds. With some dirty math (taking 31.5 inches as an arc segment of earth’s polar circumference) yields a tilt of roughly 4 milliarcseconds, an extremely small angle to say the least.

[jacobolus]

An arcsecond is 1/60 of an arcminute; an arcminute is 1/60 of a degree (°); a degree is 1/360 of a full turn. A "milliarcsecond" is probably an unfamiliar unit (an angle so slight will only be used in extremely specialized contexts), so if you like you could decimalize this to an angle of 0.000001°.

The measure of distance on earth is probably more easily comprehended by almost everyone though.

[jacquesm]

On a very large and massive object unexpected changes of such magnitude may be a 'small angle' but they still require so much energy that an explanation is warranted.

[skeledrew]

I, and I suspect many others, have no clue what an arcsecond is and thus it's significance in anything. Inches also doesn't really give accurate significance, but at least it's relatable and doesn't leave me 100% lost, and I can focus on the message that something significant has been discovered, which may require some action.

[rayiner]

Sigh. This is why I read the comments. Thank you.

[stouset]

So just to clarify, what you’re saying is that the volume of water we’ve pumped is directly responsible for the observed sea level rise? The article makes it sound as if the tilt is what was responsible, and I was curious about the mechanics of that.