A mineral produced by plate tectonics has a global cooling effect, study finds | Hacker News Reader

A mineral produced by plate tectonics has a global cooling effect, study finds

phys.org

92 pointswglb40 comments

This is a bit too simplistic and frankly bizarre without accounting for the whole earth system or well established science. Petroleum geologists have very we characterized that association of clays with organic carbon. Finding source rock is #1 in O&G exploration. Additioanlly, there is clear evidence for orbital forcing of climate via milankovich cycles. Pinning it all on plate tectonics is strange without mentioning other factors. It doesn’t really lay out that erosion of mineral rich rocks and high bathymetric relief are associated with organic production. Also that preservation is associated with rapid burial from higher rainfall/erosion and basin containers also in found in tropical transpressional and convergent margins. Additionally cooling temps may create a differential that increases ocean currents momentum and rate of upwelling (thus more production and preservation). This is well known in the Miocene and other periods. Because this happens near the tropics (there is erosion, life, and so on at the poles due to lower differentials) is not news. Overall are very unique situations where organic carbon is preserved, some can be associated with clays and some ice ages. But far from a paradigm shift. I think it’s just a bumbled headline.

Phys.org often bumbles headlines (and implications) a bit, but I like to use it as a stepping stone to the original paper (which I likely wouldn't have heard of otherwise).

Sadly the authors paper isn't easily found on the public internet for free but the abstract [1] describes coupling an idealized ophiolite obduction model with a carbon box model, giving δ13C predictions that align with known examples of cooling in rock record. As you rightly point out, this doesn't replace well studied phenomena like Milankovich cycles, but it does suggests there's more the the story. I have to say I'm not terribly surprised though, weathering of (ultra)mafic rocks has been examined as a sequestration method for at least 5 years [2] but it's still kind of neat to see models matching the rock record.

[1] https://www.nature.com/articles/s41561-023-01342-9 [2] https://www.sciencedirect.com/science/article/pii/S187661021...

I wonder how easy it would be to produce something with similar structure in volume. It doesn't sounds like a nanoscale structure and wouldn't have to be clay.

Not because nature can surely made larger volumes (this is plate tectonics after all) but to do it faster and in higher volume than we could extract from the ocean floor. Who knows how long the weathering takes, and its statistical prevalence.

Because I can never pass up a chance to mention it, the fiery core of the Earth that's moving those plates around is an approximately 45 terawatt engine; human civilization is currently around 19 terawatts.

Obviously we're not going to devote our entire economy to producing a mineral, and we're talking about millions of years versus decades, but it's still crazy to me that humans and the Earth itself operate on the same energy-scale.

Is the 49TW the total amount of energy the earth radiates from the core?

I'm struggling to reason about this. The core is a hot mass of matter, that's slowly cooling down. There is no energy "produced" here, no? So where does the 49TW go?

Edit: my questions got answered by someone posting a wikipedia link elsewhere: https://en.wikipedia.org/wiki/Geothermal_energy#Resources

Seems energy is being produced by means of radioactive decay.

> the fiery core of the Earth that's moving those plates around is an approximately 45 terawatt engine; human civilization is currently around 19 terawatts

Oh wow that is mind blowing! I would have thought we were at a smaller proportion, to be honest.

If you want to feel small again, on the other end of things, 173,000 terawatts of sunlight hits the Earth. Earth's biosphere uses something like 1% of that (depending on your definition of "used", but whatever), so we have Earth's biosphere at something like 1700 terawatts, dwarfing both us and Earth's fiery core.

The energy of sunlight that hits the ocean is absorbed, and flows into the deep ocean. A smaller percentage of the energy that hits land is absorbed, but this rapidly radiated away at night.

Ok, one last one: global warming is basically that energy imbalance: the Earth is currently absorbing, on average, more energy from the sun than it radiates back, for a variety of reasons (change in atmospheric composition, change in surface reflectivity).

That energy imbalance amounts to 500 TW.

I’m skeptical we create a level of power near 50% of the entire heat of the inner planet.

Surprisingly, it is true:

https://en.wikipedia.org/wiki/Geothermal_energy#Resources

The Earth's internal thermal energy flows to the surface by conduction at a rate of 44.2 terawatts (TW) [21], and is replenished by radioactive decay of minerals at a rate of 30 TW. [22]

[21] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/93RG0124...

[22] https://web.archive.org/web/20120217184740/http://geoheat.oi...

The parent said "power near 50% of the entire heat of the inner planet.". What you are describing sounds like the leaked power from the inner planet. These sound very different to me. One statement is about power the other about energy sitting there

Given that heat is a store of _energy_ rather than power, I don't think there's another reasonable interpretation of the _power_ of the core other than the amount that leaks.

I mean as far as production is concerned radioactive decay is the only energy source. The rest is latent heat and friction+tidal forces. The earth has been cooling and slowing rotation every since the theia impact.

The sibling comment to this one helps clear this up: In short, they're not talking about the entire heat of the inner planet. They're talking about the rate at which heat that is transferred to the surface of the planet, not the thermal energy of the interior of the planet.

> the entire heat of the inner planet

... is an energy figure, not a power figure, unless you mean either the rate at which heat is added through thermal decay, or the rate at which heat is lost through conduction to the surface, both of which are at the same mid-ten-terrawatts order of magnitude as human power usage.

Power is not the same as energy obviously, but otherwise it is the rate at which the thermal energy is spent.

~180,000TWh of annual human energy production vs ~ 3,000,000,000,000,000TWh of thermal energy inside Earth.

Over the many nuclear reactors, hydro stations, geothermal stations (which I guess is kind of cheating since it measures energy twice), tidal power stations, solar panels, wind turbines, gas and coal fired generators, and all the other odd-ball power generation devices used around the world, I could believe it. The heat can only get to a place where we actually measure it via lots of thermal mass that would slow things down.

The energy emitted from the core of the earth, and human generated power combined is most likely dwarfed by the equivalent watts from sunlight alone.

Assuming the low "realistic" estimate [0], the total amount of watts hitting the earth at any one time is 694.2 TW [1]... instantaneously. So that would add up much quicker.

Edit: I'm an idiot, the sun doesn't face the whole earth at once. It would still be a lot at half that though!

[0] https://en.wikipedia.org/wiki/Sunlight#Solar_constant [1] https://www.wolframalpha.com/input?i=%281.361+*+5.100644719%...

Integrated over the course of a day, total disk solar irradiance for a rotating planet is 1/4 the solar constant. And in our specific planetary case, about 27% is reflected without reaching ground. So the effective whole-day whole-Earth "solar constant" at ground level is about (1362 W/m^2) * 0.25 * (1 - 0.27) ~= 250 W/m^2.

https://en.wikipedia.org/wiki/Earth%27s_energy_budget#/media...

Obviously, only a very tiny proportion of that power is spent towards making the clays that we needed. We could spend a fraction of what we have and still outdo Earth by orders of magnitude.

Yeah, but we're also talking about out-doing it by about six orders of magnitude, to produce millions of years of production by the Earth in mere years by man.

So I'm not sure which one I'd bet on.

That's fascinating. Thank you for sharing. That really puts the scale of human activity into context.

Great article - right up to this quote:

"And this is also the way forward for us to find solutions for this climatic catastrophe. If you study these natural processes, there's a good chance you will stumble on something that will be actually useful."

You included only the second part of the quote. The full quote is:

"If you want to understand how nature works, you have to understand it on the mineral and grain scale, and this is also the way forward for us to find solutions for this climatic catastrophe. If you study these natural processes, there's a good chance you will stumble on something that will be actually useful."

I don't see anything wrong with including Jagoutz's thoughts on this. Maybe you disagree, but including it in the article gives us an idea of the authors' thinking.

I feel like that’s just sensationalism to get more media attention. The existing clay is formed by tectonic activity over a long period of time and using lots of energy (ie the earth’s core moving tectonic plates). Any artificial manufacturing effort would require similar energy input and it’s highly likely it requires more energy to create the clay artificially than it was to burn whatever amount of carbon gets sequestered (just guessing based on thermodynamics). So I don’t see how this clay helps us. It might be more efficient to create new clay than our existing recapture techniques although I would be skeptical.

I want to see some numbers. It's just porous mafic rock (i.e. pumice) in the presence of hot seawater.

ed. wait, no, it's felsic? but it forms quickly in marine environment... either way, there's a lot of it

Makes me think of this project: https://www.vesta.earth/

Anytime I see plate tectonics and its applications discussed it really excites me! Truly fortunate to study under a pro O&G and Diamond Geologist for a semester. Gonna write a full article now actually, will be fun!

My takeaway is his frank pragmatism: paraphrased -

the Earth will do what the Esrth does. Yes care is good but also if the Earth decides to uncork what’s under Yellowstone…

That don’t sound very pragmatic to me, more like fatalist

The two don’t always have to be mutually exclusive, no?

Depends on who you think will win in the end. Pragmatic from the Earth's perspective, fatalistic from the humans.

It would be ironic if it were discovered if are mainly the salt mines what affects the climatological cycles, when the salt, after being consumed and evacuated from our organisms due to the high doses we receive (what damage our kidneys), arrives the rivers and ends up in the oceans increasing their salinity, affecting the heat dissipation and the currents of the whole planet.

Wouldn’t this be a very tiny amount

Dietary salt yes, but counting all sources of anthropogenic salt (eg road salt) in the USA it's similar to the natural erosion rate. In other words we've roughly doubled the total salinity of American rivers.

The ocean is big so that's still not huge globally, but it can have regional effects.

https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntr...

Wow, I knew that cars and SUVs were destroying the planet because of emissions and pollution and various other factors, but I didn't even think about how road salt (only necessary because of cars) was also making things even worse.

Salt isn't even strictly necessary with cars. I always preferred unsalted roads.

Wake me up if this mean we are off the hook for the wealth transfer to the jet setting war mongering billionaire managerial class in exorbitant taxes for a lower quality of life...with a surveillance state as a bonus..."to save the planet". I'm not happy about owning nothing...

But you will be happy once you're sufficiently medicated via the patented delivery mechanism of antidepressant pharmaceuticals in industrial agriculture... :)

That's emotionlessness...not happiness. Can't wait for the next lecture from "the adults in the room" on the the virtues of colonialism & why the current war on a way of life is necessary for Democracy. Meanwhile I'm wondering how the military or the jet setting managerial class is never held responsible for its CO2 emissions...or how CO2 doomsday cult members do not seem to notice that their international CO2 summits do nothing to affect the atmospheric CO2 levels.

I'm tired of this dream of idiocracy...wake me up already

Reply on news.ycombinator.com