Our experts tackle your toughest science questions
Posted 09.09.2008 at 4:09 pm
7 Comments
Cold Snap
Everett Collection
Global warming, holes in the ozone layer, and lush golf courses in the desert all reveal mankind’s ability to mess with the planet. But the Earth’s core, protected by an outer core consisting of some 1,000 miles of 8,000˚F liquid metal, appears safe from our meddling.
Geothermal energy systems don’t drain heat directly from the core. Instead, they pull radiant heat from the crust—the rocky upper 20 or so miles of the planet’s surface—either by sucking up pockets of heated water or by circulating water through the hot rock. Power plants then use steam from the hot water to spin turbines to make electricity. Geothermal energy generates 7 to 10 billion watts worldwide, barely enough to account for 0.05 percent of global energy consumption and far less than the estimated 44 trillion watts the planet produces.
But drawing energy from the crust won’t send it into a deep freeze: Its heat is constantly renewed by the virtually continuous decay of radioactive elements sprinkled throughout it. “Cooling the Earth’s core by drawing geothermal energy from the crust is like trying to cool the western end of Lake Superior with a few ice cubes,” says Paul Richards, a professor of natural science at Columbia University.
It’s a good thing that we can’t cool the core. The spinning metal there generates Earth’s magnetic field, which protects us from deadly cosmic radiation. If the outer core cooled, the liquid would solidify, and both it and the solid inner core would grind to a halt, the magnetic field would dissipate, and high-energy cosmic radiation would bombard the planet, essentially turning Earth into a giant microwave and ending life on the surface.
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What idiot thinks that geothermal could cool the core, if every house in the world ran off of geo, the core would be mabye a fraction of a degree cooler.
I'm not quite sure how this would seem to be an issue in the first place. To my knowledge, please correct me if I'm wrong, but geothermal energy isn't extracting heat from the earth but harnessing what is already being let out. So wouldn't it be like saying by using solar power we're eventually going to cool the sun?
There are many geothermal plants around the world already, especially on Iceland. Many of them have been operational for more than 25 years, and I know for a fact that none have dropped in temperature, not even a hundred of a degree.
I think this was great point to make. As a populace of Earth we have managed to create our own worse case scenarios because we did not ask all the right questions. We should be concerned by the cooling of the planets core and we certainly should be doing more research on this before we manage to kill off life on earth because we did not anticipate that particular scenario.
Bah, slinkygenius, I don't agree. But opinions are like you-know-whats, we all have 'em.
This technology is a vastly underused resource. While working at a Natural Gas storage facility we stored hydrocarbons in underground caverns that have existed for forty years in some cases. The liquified gas would always exit at 40 deg C, and these were only one mile down in a salt cavern of 100,000 m3 capacity which cost a mere one million dollars to create. The drilling technology exists today to punch holes far deeper. I am not aware though how far the salt seams can exist underground, which is necessary because the caverns are created by dissolving salt with fresh water until the cavern is created. Perhaps someone could enlighten me as to the geology.
An interesting collection of mostly of comments that are talking about 1 piece of the whole pie. All good by themselves but the larger picture is critical to always look at. Yes logic states that by tapping into the surface temperature of the crust will most likely do nothing to the temperature of the core BUT with the idea that everything is a system we must at least give the respect to all areas of the system and how they will be effected.
I believe that this technology along with many others absolutely deserve to be implemented and should have been years ago in almost all case. They all have their place, as long as we balance their use and implement intelligently. When the black gold was discovered, in retrospect the impacts of burning it on the environment, the economy, etc. were not sufficiently weighed if at all....it was just burned. Now as a society we are COMPLETELY dependent upon oil as well as coal, and we are coming upon a situation where we have a single point of failure because there has been little to no balance for the coal/oil machine, which if wasn't already obvious the USA isn't part of. Unless individuals like Empjag have secretly invented a time machine and have not shared it, now is the time for us to start implementing renewable sources of energy such as Geothermal steam powered turbine technology on both a large scale and more importantly in our homes at an individual level.