Just to note for distant future reference, if they do cool the mantle and stop plate tectonics, carbon-based life is going to die out… Much more dangerous than Global Warming, though might take a while.
Yep, it might.
If humanity extracted the totality of the energy we are now using (about 20 TW by average) from Earth's Mantle, that'd almost double our world present cooling rate, therefore shortening the estimated 2 to 5 billion years it will take until it cools down enough to stop plate tectonics, to 1 to 2.5 billion years.
Earths heat energi content stems from thorium and uranium decay. Uranium (both 235 and 238) and thorium has a halvlife even if it counts in many billions of years.
This minuscule energi evolvement adds up over a huge volyme and is what makes Earth a geologically active planet.
If to much heat is extracted from deep underground and brought to the surface and ultimately radiated into space quicker there should be an effect. But you would need some really fancy power balance calculations to estimate it.
Not that I think geothermal can ever possibly impact on plate tectonics. The energy production from uranium and thorium occurs evenly in a ball 12 742 000 meters in diameter.
How much of its surface would even a hugely ambitious geothermal extraction programme affect? A billionth?
I haven't heard about drilling causing earthquakes. Fracking, yes, depletion of underground water tables and oil deposits, yes. Drilling per se, not that I know. Can anyone give some examples?
Unless there are examples of this, or at least a credible theory regarding a relation, I think running to the bomb shelters is a bit premature.
It is not the drilling, it is the removal of thermal energy. Rocks shrink as they cool, increasing stress, potentially leading to earthquakes and changes in volcanic eruption patterns.
Earths heat energi content stems from thorium and uranium decay. Uranium (both 235 and 238) and thorium has a halvlife even if it counts in many billions of years.
This minuscule energi evolvement adds up over a huge volyme and is what makes Earth a geologically active planet.
If to much heat is extracted from deep underground and brought to the surface and ultimately radiated into space quicker there should be an effect. But you would need some really fancy power balance calculations to estimate it.
Not that I think geothermal can ever possibly impact on plate tectonics. The energy production from uranium and thorium occurs evenly in a ball 12 742 000 meters in diameter.
How much of its surface would even a hugely ambitious geothermal extraction programme affect? A billionth?
Not sure of your point. The original issue was the potential for more and bigger earthquakes, not the end of plate tectonics.
Please note that I started with a statement that I have calculated that even at 100% conversion efficiency, the TOTAL geothermal flux of earth cannot supply the energy needed by a global middle class civilization. We would need to use STORED thermal energy and thus introduce atypical thermal stresses into the crust. What that would do to earthquakes…
If anyone had reviewed the risks of Global Warming from energy use 200 years ago, they wouldn’t have seen any.
In 200 years, US energy use per head might have gone up 50%, and the whole 50% more people worldwide might match them. That’s an enormous rise.
Currently people inject about 0.7% of atmospheric carbon dioxide into the atmosphere. Atmospheric carbon dioxide is about 3% of the CO2 in the Oceans, which is in equilibrium with the atmosphere. Yet we have models to instruct us to panic - because it suits some people’s political agenda.
My remarks about the dangers of Quaise were in jest, and I can’t worry too much about dangers to the world in a few hundred million years.
In a fraction of that time we will solve nuclear energy, and manage global CO2 levels effectively. Maybe at that point there will actually be an intelligent debate about what constitutes the optimal level. Or maybe the removers will have to nuke the adders.
