I did not specify who i think should do it. I'm not convinced either way. I think that jobs should be created, thus alleviating unemployment, and at the same time dealing with the environmental problem, to some extent. I doubt it would create a net loss of jobs if Government were to do it, especially not if tax is sharply progressive, and that way accumulating stationary wealth and also securing a long-term economic stability by making the super-rich leave.
In regards to wind energy, new technology is being deployed all the time. Just the other day, I was down at the harbour in a nearby town and a single huge blade from those new hyper-efficient high-output turbines turned the junction onto the main road on the back of a large truck.
As for nuclear, I very much dislike fission energy - I much prefer EGS.
Your presumption of economic collapse is encouraged by the misguided perception that society is static. I am not suggesting primitivism, I am suggested that pollution is eliminated. The technology exists to achieve this. To pre-empt your argument, remember that people will be employed to fit, make, collect resources for and prepare the new equipment. I don't know if it would be a net gain or loss, but it certainly wouldn't be as devastating as you suggest, if it is at all. In any case, securing the future of humanity should be the primary consideration.