Well, maybe. We can probably meet our current energy needs with solar/wind and some kind of energy storage and more long-distance transmission lines, but it won't be cheap or easy. (Maybe it'll be cheap in the long run, but in the short run it's a lot of infrastructure to build out.)

Fusion shouldn't be considered an essential prerequisite to address climate change, but it would be better to have it as an option than not. Being able to generate constant power reliably is very convenient.