My Views: I would love it if Solar, Hydro and Wind and other renewable sources of energy + Non Renewable Nuclear were to provide enough energy reliably to completely replace fossil fuels, but I know it's not a feasible solution at least at this point. And maybe it will never be. Renewable sources of energy are highly dependent on some metal mining (some are rare metals) and I doubt if the prices of those metals would go lower as the demand for those renewable sources of energy sky rockets. i.e., It's a non-linear equation, the price of renewables will not remain the same if we want to meet 100% of our energy needs from renewables. So, Just Stopping Oil is a pretty stupid idea concocted by people who have a much better standard of living than me.
Skip This if you must: As an Indian, I can speak for 1.4B people (I asked) when I say that, no matter how much pressure developed nations impose on India and countries like India, we will still keep using the least costliest source of energy, because we too want nice things and we too want our women to be liberated from cow dung/wood stoves and from the burden of washing clothes and utensils. So yeah, there is no way bar great scientific innovation which will phase out fossil fuels at least in the near future and perhaps ever.
PS: I don't like fossil fuels, I don't like the pollution or the effect it has on the environment and I wish they could be replaced by something renewable, but I just don't like the chances of that happening.
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.