The more buildings decay on a planet, the more a new resource bar should grow: Scrap.
In the beginning everybody will ignore it, because a tiny sliver or scrap is not worth extracting. But the bar will keep growing until it becomes worth it to set extractors to Scrap and get AL and FE that way.
Similarly the more people consume stuff the more a waste resource bar should grow, spurring the creation of water sanitation industry and biomass recycling industry.
The more you burn stuff, the more CO2 should appear, spurring the creation of carbon capture industry. (Turn CO2 back into C and O).
The idea of waste products has been proposed before, and we always picked it apart. But those ideas were usually on an individual player basis, where byproducts accumulate in your base and have to be dealt with.
This version seems much better. There could be a “Pollution” bar on each planet, and it grows faster the more production buildings there are in total. As pollution increases, resource extraction and farming industries starts to suffer a penalty to efficiency. Eventually, pollution will totally swamp the value of the resources on the planet.
Players can reduce the pollution bar by constructing a planet building and feeding it consumables, this would usually be managed by the governor.
that would be neat, like a new population infrastructure class of building. instead of pioneers suffering from lack of DW and SUN it would be your bottom line, haha
It really gets interesting if the industries that are most effected are different from the heaviest polluters. e.g. farming and water extraction suffer the worst reduction as a result of pollution, but don’t create much pollution themselves. Meanwhile, smelting has a massive effect, but not much penalty. Then there can be endless bickering over whether tax rates should be higher for smelters, since they cause the issue, or higher for farmers, since they’re the ones complaining about the results. Planets can declare themselves to be “clean” or “dirty” and try to discourage the “wrong” sort of industries from starting there.