Last time I was talking about how since nothing is created or destroyed, we can always return the earth to it’s previous state, no matter how much damage we’ve done (assuming we live long enough to improve our technology). Now I’m going to explain how that’s not true. It’s because of the universal downer of physics; Entropy.
So here’s the thing about that hydrocarbons example and the CO2 we release into the air; there’s a crucial element that’s changed and it’s not matter. The fossil fuels we dig out of the ground are in a highly concentrated state of energy. That’s why we love burning them, they release a massive amount of energy per weight. That energy is ultimately from the sun; first plants concentrated the solar energy into sugars, then animals ate them and further concentrated them into fats, then the animals died and were compressed over a long time into the sludge we pump out of the ground. That energy is in a low entropy state. When we burn them, the resulting energy is in a higher entropy state.
Entropy can be created. In fact, it’s always being created, you can’t stop it. Everything that happens in the universe is a gradual shift from low entropy to high entropy. Every chemical reaction will tend to disperse the energy over a larger area; high concentrations always flow to low concentrations, never the reverse.
Well, that is if you look at the system as a whole. So life on earth is able to concentrate energy because the sun is gradually dispersing it’s energy throughout the solar system. The entire closed system, the solar system, is gradually increasing in entropy over time. Now this is a very, very long term problem. It’s not a pressing issue. It’s not even a problem for humans because if our decedents actually survive to the point that they must grapple with this, they will no longer be humans. Either evolution or technology will have rendered them completely alien to us. Not really our problem then.
What is our problem is the short term supply of low entropy chemicals. Hydrocarbons are so attractive because they’ve concentrated the energy we so love into such a small package. Until we can recreate those forces which replenish them, we will be depleting our supply. And without that low entropy energy, we can’t power our technology. And our technology is the only thing that can save civilization as we know it.
Then again, maybe it’s better if our civilization doesn’t survive. Maybe we want something better?