[HN Gopher] A mineral produced by plate tectonics has a global c...
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       A mineral produced by plate tectonics has a global cooling effect,
       study finds
        
       Author : wglb
       Score  : 35 points
       Date   : 2023-12-05 03:03 UTC (19 hours ago)
        
 (HTM) web link (phys.org)
 (TXT) w3m dump (phys.org)
        
       | dadjoker wrote:
       | 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."
        
         | vlovich123 wrote:
         | 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.
        
           | lainga wrote:
           | 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
        
         | onionisafruit wrote:
         | 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.
        
       | gumby wrote:
       | 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.
        
         | saalweachter wrote:
         | 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.
        
           | redblacktree wrote:
           | That's fascinating. Thank you for sharing. That really puts
           | the scale of human activity into context.
        
           | Arrath wrote:
           | > 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.
        
             | saalweachter wrote:
             | 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.
        
           | bilsbie wrote:
           | I'm skeptical we create a level of power near 50% of the
           | entire heat of the inner planet.
        
             | philipkglass wrote:
             | 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/10.1029/93
             | RG0124...
             | 
             | [22] https://web.archive.org/web/20120217184740/http://geoh
             | eat.oi...
        
             | etskinner wrote:
             | 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.
        
               | jl6 wrote:
               | ~180,000TWh of annual human energy production vs ~
               | 3,000,000,000,000,000TWh of thermal energy inside Earth.
        
               | thriftwy wrote:
               | Power is not the same as energy obviously, but otherwise
               | it _is_ the rate at which the thermal energy is spent.
        
               | mitthrowaway2 wrote:
               | > 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.
        
             | graypegg wrote:
             | 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+*+5.10064
             | 4719%...
        
               | lainga wrote:
               | 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#/me
               | dia...
        
           | thriftwy wrote:
           | 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.
        
             | saalweachter wrote:
             | 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.
        
           | beAbU wrote:
           | 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.
        
       | ecoffey wrote:
       | Makes me think of this project: https://www.vesta.earth/
        
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       (page generated 2023-12-05 23:00 UTC)