It will just take at least three or four generations to get back to 90's climate, provided we don't trigger any irreversible tipping points, like the melting of the permafrost, in which case the climate is messed up for millennia.

The melting of the permafrost is already underway and it's not looking good for any hope of it slowing down, and that's only one (of many) irreversible tipping point we're facing right now. But hey, it'll be fine because it's all just "fake news" anyhow. (I wish that were actually true about it not being real, but it's crystal clear to anyone with an IQ higher than a houseplant that the scientists were right all along and we really should have started acting on all this stuff decades ago.) :(