Fucked yes, doomed maybe not. The most practical solution is also the most impractical, given our current situation. Call it communism or call it a blue donkey if you want, but centrally planned carbon rationing based on projections of emissions is about the only genuine hope future generations have. We know how much we can emit. We have known for a long time. Now, comes the tricky part. How do we maintain a functional civilization while also drastically reducing emissions to meet the goal of carbon zero?
Computer models can help us keep track of carbon production in real time and even be converted to manage specific sectors. This is where the central planning aspect comes in. The average person should not be a victim of these changes. Folks still need to go to work, pay rent and all the basic requirements of life. Instead of a carbon tax, we need a carbon ration which starts at the bottom of society then goes upward to the highest producers. As we go up the ladder, the amount of carbon allowed to be produced on a single hypothetical day shrinks. Eventually reaching those industries and individuals doing the most damage, then putting the burden of reduction on them. The rich/Corporations can find those solutions easily. There will be some instability and no doubt chaos, but they have the resources needed. Amazon, for example, already uses tons of metadata to plan the most efficient routes.