What did the Marshall plan require? We need that.
We don't need to rebuild, we need to stop doing most everything that keeps our economy and infrastructure functional. Immediate stop and worry about a "green" alternative later.
Just a sampling of what would be required on a global scale starting rightnow, not tomorrow or next year:
* Ground all planes, stop 100% of air traffic
* Ground all cars and trucks, no one drives anywhere
* Stop all land clearing or development. If land can grow trees, plant trees, then leave it alone
* Stop all construction using cement (roads, bridges, building, you name it, stop it)
* Shut down oil industry and all energy sources that burn oil-based fuel
* Shut down cattle/beef industry
* Stop having extra babies. One per couple.
* Stop all commercial fishing
* Stop making plastic anything
If we did ALL of these things today, this minute, we still would not avoid damaging climate change -- we're already locked in to 2 degrees warming from the greenhouse gases currently in the atmosphere, that won't degrade for decades. We
might avoid catastrophic climate change, but we don't know for sure. The WAIS is already destabilized and collapsing, continental glaciers will be gone before the end of the century, and thawing permafrost is emitting methane gases at increasing rates.
The only proactive action we could take is to sequester carbon, and we can't do that on a meaningful industrial scale yet. We don't have the technology.
Are we going to do any of these things? No, of course not. Because our economy would go belly up and most people would be trapped in their homes starving to death. But anything less will not be enough.
tl:dr - we're totally screwed