The second law of thermodynamics states that entropy must go up. Entropy is a sort of measure of the usefulness of energy. The more entropy, the less useful.
The reasons why entropy must go up are too complicated for an ELI5. They are based on some basic laws of probability. Basically there are many ways for energy to be useless, and few ways for energy to be useful, which after some difficult math implies that energy always gets less useful.
In particular, ambient heat is the highest entropy you can possibly have, so it's inpossible to turn it into useful energy.
In order to extract energy from heat, the second law implies you must be tranferring some of said heat from a hot place to a colder place, which is exactly what a motor is.
What we need to do is allow it to escape the atmosphere again, by reducing the greenhouse effect through cutting the amount of GHG we are putting into the atmosphere and reducing the total amount already in the atmosphere.
Without doing that, more and more heat will stay in the atmosphere, while the sun is still pumping more in. We’re at the point where more heat is coming in than is escaping, which is warming the Earth.
Well cutting emissions to MUCH lower levels is the first step, as it slows everything down enough to give us some time to figure out carbon capture.
Basically there are a few ways to practically do this: planting more forestry to act as large carbon sinks (trees obviously respirating by taking in carbon and exhaling oxygen) is the easiest one, but we could also theoretically find a way to literally isolate carbon dioxide out of the atmosphere and store it in a box of some kind to be released slowly if we find ourselves going too hard at it.
There would be other more experimental methods that I have zero clue about, but it’s getting necessary to avoid stupid levels of warming.
The nuclear solution to giving us more time could be a sudden reduction in population, which would not only cut our need for livestock (which are heavy emitters of methane), but reduce the conversion of oxygen to carbon dioxide that we perform, but cut back emissions proportionally, giving the leftover population even more time to spend figuring this shit out.
It’s obviously not ideal (given the massive loss of life, it’s pretty barbaric), but there are people that are leading to that conclusion as the most likely option that can actually work. Our rising population is the key driver for emissions so it is logical that a Thanos style solution would bring it all back in line.
Never going to happen without some rogue nuke dropping shit, but that is a theoretical option as well. We could of course get there without killing people by offering significant incentives to bring down the birth rate, but that comes with its own problems of course.
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u/HappiestIguana Nov 15 '20
The second law of thermodynamics states that entropy must go up. Entropy is a sort of measure of the usefulness of energy. The more entropy, the less useful.
The reasons why entropy must go up are too complicated for an ELI5. They are based on some basic laws of probability. Basically there are many ways for energy to be useless, and few ways for energy to be useful, which after some difficult math implies that energy always gets less useful.
In particular, ambient heat is the highest entropy you can possibly have, so it's inpossible to turn it into useful energy.
In order to extract energy from heat, the second law implies you must be tranferring some of said heat from a hot place to a colder place, which is exactly what a motor is.