Guest “I couldn’t make this sort of schist up, even if I was trying” by David Middleton
‘Unprecedented’ Sea Level Rise Is Making Earth’s Days Longer
Published Jul 15, 2024 at 3:00 PM EDT
By Jess Thomson
Science Reporter
Our changing climate is impacting our planet in a huge number of ways—ranging from powerful hurricanes and intense droughts to invasive species and ocean acidification—but there might be another bizarre effect that you’ve never heard of.
Climate change might actually be slowly changing the length of a day on Earth, according to a new paper in the journal Proceedings of the National Academy of Sciences.
This is a result of sea levels rising—because of increased temperatures and the melting of the polar ice caps—thereby causing a redistribution of mass from the poles of our planet toward the equator.
[…]
Newsweek
Newsweek? They’re still in business?
The PNAS article is pay-walled. However, the abstract says it all…
Abstract
The melting of ice sheets and global glaciers results in sea-level rise, a pole-to-equator mass transport increasing Earth’s oblateness and resulting in an increase in the length of day (LOD). Here, we use observations and reconstructions of mass variations at the Earth’s surface since 1900 to show that the climate-induced LOD trend hovered between 0.3 and 1.0 ms/cy in the 20th century, but has accelerated to 1.33 ± 0.03 ms/cy since 2000. We further show that surface mass transport fully explains the accelerating trend in the Earth oblateness observed in the past three decades. We derive an independent measure of the decreasing LOD trend induced by Glacial Isostatic Adjustment (GIA) of −0.80 ± 0.10 ms/cy, which provides a constraint for the mantle viscosity. The sum of this GIA rate and lunar tidal friction fully explains the secular LOD trend that is inferred from the eclipse record in the past three millennia prior to the onset of contemporary climate change. Projections of future climate warming under high emission scenarios suggest that the climate-induced LOD rate may reach 2.62 ± 0.79 ms/cy by 2100, overtaking lunar tidal friction as the single most important contributor to the long-term LOD variations.
PNAS
It’s models all the way down. There’s no way to measure fractions of milliseconds per century (ms/cy) changes in the length of day (LOD) over any time period, much less at a centennial to decadal scale. Might as well try to determine “How many angels can dance on the head of a pin?”
The LOD has been generally increasing over geologic time (Mitchell & Kirscher, 2023). As the Earth has pushed the Moon farther away, the Earth’s rotation has slowed down.
1.33 ms/cy = 0.0000133 s/yr
At a rate of 0.0000133 seconds per year, in 80 million years, the sidereal day will be 18 minutes longer than it currently is.
Back in the Cretaceous Period (~80 mya), when sea level was much higher than it is today and there was little to no polar ice, the days were about 23.5 hours long (de Winter et al., 2020). The rate of LOD change from 80 mya to present (1950 AD) was about 2.25 ms/cy.
Allow this to sink in: The rate of LOD change from 80 mya to 1950 AD was about +2.25 ms/cy. The rate of LOD change since 2000 AD, allegedly driven by “‘unprecedented’ sea level rise is only +1.33 ms/cy.
Of course, there are no Cretaceous measurements of LOD. This is based on reconstructions from rudist shells and models… And the error bars are in days and hours… not milliseconds.
Measuring LOD
Current LOD can be directly measured very precisely. Schreiber et al., 2023 employed “a laser ring gyroscope” to measure changes in the sidereal day. They found that the LOD fluctuated by as much as 6 ms over the 120-day measurement period.
If LOD fluctuates by 6 ms over a two month period a 1.33 ± 0.03 ms/century increase in the LOD is about as relevant as a 1-3 mm/yr rate of sea level rise is to a 1 meter daily tidal range.
References
de Winter, N.J., Goderis, S., Van Malderen, S.J.M., Sinnesael, M., Vansteenberge, S., Snoeck, C., Belza, J., Vanhaecke, F. and Claeys, P. (2020), Subdaily-Scale Chemical Variability in a Torreites Sanchezi Rudist Shell: Implications for Rudist Paleobiology and the Cretaceous Day-Night Cycle. Paleoceanography and Paleoclimatology, 35: e2019PA003723. https://doi.org/10.1029/2019PA003723
Mitchell, R.N., Kirscher, U. Mid-Proterozoic day length stalled by tidal resonance. Nat. Geosci. 16, 567–569 (2023). https://doi.org/10.1038/s41561-023-01202-6
Schreiber, K.U., Kodet, J., Hugentobler, U. et al. Variations in the Earth’s rotation rate measured with a ring laser interferometer. Nat. Photon. 17, 1054–1058 (2023). https://doi.org/10.1038/s41566-023-01286-x
Shahvandi MK, Adhikari S, Dumberry M, Mishra S, Soja B. The increasingly dominant role of climate change on length of day variations. Proc Natl Acad Sci U S A. 2024 Jul 23;121(30):e2406930121. doi: 10.1073/pnas.2406930121. Epub 2024 Jul 15. PMID: 39008671.
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David, you said
The LOD has been generally increasing over geologic time (Mitchell & Kirscher, 2023). As the Earth has pushed the Moon farther away, the Earth’s rotation has slowed down.
I thought bodies like the earth and moon could only attract each other through gravity. They can repel one another, too? Can you explain, and fix this deficiency in my science education?
Thank you.
Measurements of the lunar distance are made by measuring the time taken for laser beam light to travel between stations on Earth and retroreflectors placed on the Moon. The Moon is spiraling away from Earth at an average rate of 1.5 in per year.
It’s a matter of gravity vs angular momentum.
https://www.nature.com/articles/s41561-023-01202-6
Thank you. Learned something new today!
Does this mean that when Leif Erickson was exploring Greenland back during the Medieval Warm Period, with higher sea levels than now, the days were very slightly longer back then than now? Unfortunately, he didn’t notice the difference.
This doesn’t rise to the “sloped roof” level of stupidity, but it’s getting close.
I understand that her primary security experience was while working for Pepsico. I’m not sure that preventing theft of soda drinks rises to the same level as securing the safety of a past, and hopefully future, president. However, she is good friends with Jill Biden.
Well, I suppose that increasing sea level could by itself lead to a longer day. Transporting one grain of sand from the Arctic shoreline of Siberia to an island on the equator also theoretically increases length of day.
And with both instances, the proper response is “so what?”.
Aside from the effects of our lunar orbit gradually increasing in radius, I can easily think of other factors that can create an opposite effect on rotational momentum, such as the effects of plate tectonics moving the plates around on which continents now sit. And the effects of plate tectonics on building up the heights of relatively young mountain ranges like the Himalayas and Rocky Mountains … along with pushing up relatively high plains. And the effects of erosion of all land surfaces where sand and silt move from exposed land to the oceans.
Not to mention the effects of our sister planets’ positions relative to Earth that exert varying gravitational forces. Plus the effects of differential rotation between the Earth’s inner metallic core and the outer core and mantel (a process only recently quantified).
Plus in addition to all those other factors that affect Earth’s LOD, there are the effects of the actual and radical climate changes of the Pleistocene and its cycle of glaciations and interglacials that are vastly more significant than anything that has been claimed for human-induced climate changes.
The essential fallacy of warmunists is that they claim that any single process of their choosing and its net effects on anything in our world can be modeled effectively in a vacuum, as if all those other processes interacting in our complex astrophysical, geological, and biological system we call the Earth and the universe did not exist.
And they call us “unscientific”! They are all simpletons.
And with both instances, the proper response is “Cool! That’s a fun idea.”
I still want to know how much windmills contribute to windless days, and also how many it would take to end wind.
“Transporting one grain of sand from the Arctic shoreline of Siberia to an island on the equator also theoretically increases length of day.”
How about all those Canadians moving to Florida in winter and back in the spring? I can feel the wobble even now.
In some cases, transporting the sand will make the world spin slower. If the new location is closer to the spin axis than the old location.
Figure skaters know this.
If rising sea levels affect the rotation period of the earth then what affect would the glaciers during the last glaciation period have had?
The moon is slowing the earth’s rotation due to gravity, but it’s such a slow process that the sun will burn out and die long before Earth would tide lock to the moon. And this is a fast process compared to what this article is claiming global climate warming cooling change crisis is doing to the earth’s rate of spin, so….. not something I can bring myself to care about.
Days are getting longer and I thought it was my imagination. All that’s needed now is a falsifiable hypothesis to confirm it’s not my imagination.
Is the mass gain from meteor impact not affecting rotation?
I really have no idea why LOD needs to be known about by the vast numbers of WUWT readers here.
Surely is is not being mentioned as a part of a global emergency scenario.
Geoff S
From one of the authors of the paper:
“Even if the Earth’s rotation is changing only slowly, this effect has to be taken into account when navigating in space – for example, when sending a space probe to land on another planet,” Soja says. Even a slight deviation of just one centimeter on Earth can grow to a deviation of hundreds of meters over the huge distances involved. “Otherwise, it won’t be possible to land in a specific crater on Mars,” he says.
He apparently hasn’t heard of “mid-course corrections.”
Well, that’s all due to the tilt of the Earth’s axis.
The “Existential Threat” is that the Earth’s axis will reach a point where Man’s CO2 will cause a “tipping point”.
When Guam capsizes, we’ll know it’s too late!
To prevent that, buy an EV.
Two USGS geologists in “A Search for Scale in Sea-Level Studies,” Journal of Coastal Research, July 2006 in which they concluded from examining coastal peat bogs and river sediments on the US east coast that the seas have been rising at a rate of 1-2 mm/yr for the past 6,000 years. Before that, seas rose much much faster as the glacial ice sheets from the previous glacial age melted. Perhaps a model of water behavior considering these facts might conclude that the Earth does not rotate anymore and the sunrises and sunsets we observe are a fiction.
If glaciers are melting, it has the opposite effect. The water flows to a level closer to the center of the planet and that will speed up rotation and shorten days.
Figure skaters know this.
The Earth is an oblate spheroid, flattened at the Poles and bulging at the Equator. Therefore, ice mass moved to low latitudes will slow rotation. However, so will accumulating meteorite dust.
Very nice David.
“If LOD fluctuates by 6 ms over a two month period a 1.33 ± 0.03 ms/century increase in the LOD is about as relevant as a 1-3 mm/yr rate of sea level rise is to a 1 meter daily tidal range.”
Considering the above sentence why would any science journal publish a study this bad. Do science journals have no standards to abide by?
That’s a topic of a post I haven’t figured out how to write yet… 😅
So long as it bolsters the cause…conflates an issue with climate change and spells doom and gloom…journals will publish it. If it speaks any truth to the lack of catastrophe or against the narrative, good luck getting published anywhere
These stories count on ignorant readers not understanding that sea level has been rising since the end of the last ice age, and the rate of increase of sea level rise has not changed in the last century. They conflate an effect that has been going on since the dawn of time with something to do with climate change.
As well as making the days longer, it appears that CO2 emissions also make the days shorter…
https://www.npr.org/2022/08/04/1115541992/the-earth-is-spinning-faster-than-ever-and-its-making-our-days-shorter
There is nothing that CO2 cannot do.
The Atlantic ridge is spreading at approximately 0.01 metres per year. Whilst the Nazca plate is subducting at 0.077 metres a year. What effect does these albeit small movements have on the dynamics of the earth’s rotation?
Would not this increase in day length get climate change over with sooner? /s
Earthquake a few years back in Japan altered the rotation of the planet. I recall it in the 10s of micro seconds.
Major hydro dam in China changed the rotation of the planet due to the mass of the elevated water. I do not recall the number, but it was real.
Lots of things affect the precision of the 24 hour day.
Although I believe this issue is immaterial, if one assumes it is actual, can someone explain why the opposite would not be true when the planet cooled in the past ( or future) and ice formed on the poles, leaving less water in the equatorial region.
Damn! It looks like I’ll be 21 minutes early for my dentist appointment in 1,002,024 next Thursday.