I'm in the it's happening camp but instead of trying to prevent it, we need to adapt to it.
We'll have to do that also, and if the problem was just a single, one-time step-change (i.e. "we'll have to live in temperature range B from now on, instead of traditional temperature range A"), that would be sufficient.
But it's not that easy, is it? The climate changes, and as long as we keep increasing the CO2 content of the amosphere, the climate keeps changing more.
So we could adapt to the climate we expect to be living in 20 years from now, but without also solving the emissions problem, that won't be enough: we'll have to adapt again some years after that, to a climate that's even worse. And again, some years after that, and so on, likely until our only remaining way to "adapt" is through mass die-offs.