Energy investments are some 3% of the GDP, diverting those is an almost complete non-brainier. But we'd need to get about as much from other places.
You have to make up your mind, if you are concerned about real resources or fictional ones.
If we want to optimise for real resources we would round up all the people who’s job is to destroy real resources, like casino pit bosses and the managers of Prada and fast fashion that destroy clothing to create artificial scarcity.
And we would kick them out in the rain to do tree planting.
Climate change threatens a lot more than 5% of real reseouces - in fact what happens when the Middle East and American Midwest runs out of underground water reserves?
It's not a neck and neck race, what has happened is one region drains its aquifers first and then silently raids the other's ...
* https://www.pbs.org/newshour/politics/in-drought-stricken-ar...
* https://www.cbsnews.com/news/saudi-company-fondomonte-arizon...
Anyway, that's what my sort of point is. Much of the GDP is spent on dumb stuff like holding stocks, gold, art and Prada bags. When you divert a percentage of that to be spent on real resources it can have major effects. Kind of like how when leisure travel became affordable for regular people, suddenly air travel and cruise ships started to have an outsized effect on climate.
Unfortunately it’s all part of the same tragedy of the commons and coordination problem.
IMO for labor, I'd say ~80% of jobs are more or less completely worthless. Many, many industries don't produce anything at all, they just move intellectual stuff from point A to point B, slap their existence on it, and shave off a few cents for themselves.
At some point we will find a series of bottlenecks. But up to a 30% reduction (with ~100% clean electricity) it's obviously clear, and it looks doable up to ~90% (electricity, transportation, heating, and some industry converted).