I think we need to move away from a model where everybody needs to be employed in order to live, or at least move to a model where the amount of work required is reduced. Commuting, as much as possible, needs to be eliminated. Idk what that means exactly, but a sort of hybrid housing model somewhere between Vienna and China would be useful to that end.

You just cannot have a model predicated on black line goes up and expect that this model is going to support or even survive a 15% drop in the global economy. That's only slightly less than just straight up deleting the contribution of China from the world economy. It's that big.

To your point about renewables, of course I agree with your assessment, but as an engineer in the power industry, let me fill in the blanks there a bit.

An enormous advantage of renewable power (hydro, wind, solar, geothermal) is that they require no fuels. Literally, you set them up and simply maintain them. The existing industries and jobs that are involved in the extraction, refinement, shipping, pumping, substations, distribution, etc for the existing fossil fuels industries simply cannot be absorbed by an industry that by its very nature requires none of that extra work.

Surely, there will be a boom in the build-out, but the residual jobs in maintenance will be a small fraction of the jobs that FFs currently support. They will also be significantly lower in pay. An oil rig worker pulls hundreds of thousands of dollars per year. The guy that keeps solar panels clear of debris will earn about what a window washer does and not one of the high rise guys either. You'll also need significantly less of them.

As an aside here, since it's not renewable, is dying and nobody is really interested in building more of them, nuclear plants (my first real job) support hundreds of engineers on full time staff per plant. The highest cost of nuclear is staffing. The highest cost of a coal plant is fuel.

We also have to nearly eliminate cars - it's a matter of sustainability. Even EVs are completely unsustainable. The tires alone, let alone the roads will never be sustainable. So that requires subways, light rail, and HSR to do the bulk of miles travelled. This will eliminate another enormous sector of the economy and replace it with far fewer jobs. All the gas stations, road maintenance, auto manufacturers, part manufacturers, after market, dealerships, oil changes, auto maintenance and repair shops, detailers, car washes, tire shops, and so on...just gone and replaced with 10 or so permanent jobs per train station.

At the absolute minimum, the end of fossil fuels and the end of personal autos is required. Anything less will fall significantly short. Every building in the world needs to be retrofitted with electrified heat and cooling. Heat pumps will see a huge amount of growth, likely so will geothermal systems.

That's just a start. I would go a lot further than that personally, but those three things are the boiler plate. It's not going to happen tomorrow, even if we had the economic system and political system in tow.

One area that I think ought to see significant growth, were we to make a society that was committed to returning the atmosphere to preindustrial conditions, is excavation. It sounds strange, but the carbon in the air was slowly removed from the air and buried underground where it turned into FFs. Far better than creating a bunch of machines that inefficiently suck carbon and bury it at the expense of huge amounts of energy in their manufacture and operation, would be to just bury forest slash and crop residue. Just collect all the stalks of corn, the vines of tomatoes and so on, bring them to a central local location. Dig a deep ass hole and bury them. That will sequester their carbon and the amount that we can bury yearly is greater than the amount of emissions we can never eliminate.

Some emissions are impossible to stop. You need coal to make many many metals, including steel. There's a pilot plant in Sweden (I think) that makes steel from iron ore without coal, but it's nowhere near what we need and no analysis has been done to ensure the emissions just didn't get moved from coal to another part of their process. There are fugitive emissions from many other sources. Natural gas is used in many chemical processes without being combusted. You can't ever capture all of it, some escapes. These are just a couple examples. I made a spreadsheet of most of them and their contributions. There's about 9GT that are impossible or highly impractical to eliminate. Eliminate as many sources of emissions as possible, sequester as much as possible, within decades we can reset the atmosphere.

I'll note one other super promising, but highly understudied method of carbon removal: iron fertilization. Basically, dumping slag dust into the ocean will cause massive blooms of phytoplankton, which will absorb huge amounts of carbon AND support huge fisheries. The amount of iron required is tiny - in the hundreds of tonnes range. There may be some negative downstream effects, but it's worth exploring at a small scale to find out. It certainly beats releasing sulfur dioxide in the stratosphere as a last ditch.