[YawningAngel]

I didn't word this very well. What I mean is that there are/were no huge engineering challenges involved. We can't build a space elevator at any price, we can massively reduce our emissions by 'merely' spending a truly unfathomable amount of money

[pedrocr]

Do you have a source on it being such a large amount of money? My impression is that just like water rights we've priced the externality so low that a lot of things weren't done even though they were cheap. Here's a 2007 analysis putting the cost at less than 1% GDP:

https://www.mckinsey.com/business-functions/sustainability/o...