If it is solved it will definitely be through technology of some sort. While I agree it will not be one brilliant scientist, technology will be the solution.
That technology may come in the form of a way to produce more energy without fucking up the climate, and the engineering and logistical capacity to roll out the change at a breakneck pace.
It may come in the form of simply developing a way to control the global climate directly.
It might come in the form of some technology to control the behavior of humans so that we can actually respond appropriately.
Or it might come in the form of the singularity, when self improving machines grow so far beyond us so fast that they can just do what is needed whether we like it or not.
But one way or another I guarantee that if it’s solved, it’ll largely be a technological solution, because getting humanity to just…stop using energy at our current rate…is just not going to happen.