The problem is the address
Heavy industry is not the enemy. It is the reason most people alive today have clean water, medicine, and a roof. The problem is not that we mine, smelt, and manufacture. The problem is that we do all of it on the only planet known to hold life.
Every mine is a hole in something that was alive. Every smelter puts its exhaust into the air we breathe. We have gotten better at controlling the damage, and we should keep getting better, but the arithmetic does not change. A finite planet cannot host unlimited industry and remain a good place to live.
Move the extraction off Earth
There is a way out that does not require anyone to give anything up.
The resources are already there. They sit in bodies with no biosphere to damage, no groundwater to poison, and no neighbors to relocate. An asteroid is a rock that has been waiting four billion years for someone to come get it. Mining it costs the solar system nothing.
The Garden Planet
This is what iGO means by Operation Green Earth. Not a smaller human civilization, but a larger one, with its dirtiest work happening where dirt does not matter. Earth keeps the part that has to be here: people, agriculture, the biosphere, the places worth protecting. The rest goes up.
A Garden Planet is not a park with the gates locked. It is a working world that stopped having to strip-mine itself to function.
Water first
We are starting with water, because nothing else moves until propellant, air, and shielding are available off Earth. Water is the first step in a chain that ends with industry that never needed this planet’s crust in the first place.
That is a long road. We insist on it anyway.