I understand what you mean when you draw a line between natural and unnatural, such as us intervening with raw materials and converting them to better suit us. Like plastic. Or pulling metal ore from the dirt, and manufacturing steel, and making cars and other things with it in great numbers, or turning sand into glass, except we do it on purpose. All that stuff we do with given materials.
Nature is fine with us doing these things with the available materials. The 1 thing that threatens us as a species, is greed.
Even when it comes to the energy business. Anyone or anything that threatens big oil, is very likely to be silenced. Not only that, but the system at the very least, claims it needs oil. It's true if oil was replaced by something else, entire economies that relied on the sale of oil will have some serious issues.
There are 2 stories for inventor Stanley Meyer, who made a car run on water. His system was based on an electrolysis that took place in a tank he replaced the gas tank with, and in the electronic process it would take the H2o and separate the hydrogen from the oxygen.
On a side note hydrogen is 100% clean and 20 times more combustible than gasoline. Science knows this, but the system leading to the combustion engine are all rigged to burn gasoline, which is made up of crude oil. By your definition, gasoline is unnatural, and would be more unnatural than induced hydrogen.
Another thing about the hydro cell. They never released them until they can figure out a way to make money off of it. See they say the hydrogen extraction process requires burning natural gas. But this can be done electronically, and we know the nature of alternators in cars. They'll keep the battery charged, until the battery itself reaches the end of it's lifespan.
There are 2 stories about Stanley Meyer's death. One of his documentary's reported he was found dead on railroad tracks, and they found alcohol in his blood, but the documentary also had many of his friends who all said he never drank. And how he was being intimidated for years over his car that can run on water.
On Wikipedia, last I looked, it simply says Stanley Meyer's died of food poisoning.
It's important to note, that if all we had to do was put water in our cars, endless amounts of money would not continue to fall into the hands of big oil.
The effects of greed is behind all negative effects we have on the environment, even when it comes to animal extinction, and endangerment. Even an atheist can see, if nature is to punish us for anything, it'll do it over our failure to let go of the inferior system that enriches the 1% and move on to one that enriches us all, we already know the clean energy is the solution to energy crisis, and it can recycle itself for a lot cheaper.
Another thing about those big banks. Namely J.P. Morgan. The man himself prevented Nikola Tesla from achieving his grandest scheme, which Tesla himself believed would supply the world with unlimited free energy and wireless. Because there was way to meter such a thing, Morgan pulled the plug on the project, and made powerful people enemies of Tesla to ensure this project doesn't ever come into effect.
Today we see Universities powering things wirelessly, the way Tesla was able to do it, 100 years ago.