On one hand many countries will invest in heavy industry, manufacturing, and fall back to fossil fuels.
On the other hand, economy overall should slow down and consumption of non-essential goods and services will drop.
I’m not expecting any definite answers or numbers, of course, just some food for thought.
Well, if you have to build all kinds of stuff to win (or even survive) things like environmental regulations go out the window. You can expect factories, many not meant for it, to start running 24/7 and producing all kinds of pollution. People will need to get to those factories and it’s also all using more power. All of those things also need to be shipped around, both to temporary storage and to staging areas for wherever they’re destined.
During WWII in the US, a lot of old mines were also re-opened to get what was left of lead, copper, zinc, etc. and mining can have a huge environmental impact. I suspect we’d see that again along with rare earths mining and refining which is not great for the environment. I suspect we’d see more coal mining, facking, and other things as well to meet energy needs at home and abroad.
There will be tons of fires pumping carbon and I’m sure plenty of nasty materials into the atmosphere as well. Lead is going to end up all over the place in some areas and probably depleted uranium as well (you can see what that’s done over time in various parts of the Middle East).