I think that we will reach net energy output within 30 years, with another 30 to actually scale that into a usable reactor, then another 30 to actually start using it widespread, and that's assuming that costs continue to decrease on things like superconductors, and we get our tritium supply chain to exist. I'm a little biased as a student going into the field, but I'm hopeful.

Unfortunately Fusion is too far in the future to solve climate change. There are still a bunch of hurdles we need to pass to start making feasible commercial reactors, so investment into other fields is necessary for the short term.