Do we?

Setting aside the issue of people who would refuse to go vegetarian, getting everyone on the same page politically, etc, we're at the brink of environmental collapse (at least the food-chain is) and the IPCC models of keeping warming under 2°C rely on wildly optimistic predictions about our future carbon capture abilities with basically no basis in our present reality.

And that's not even getting into how hopeless our ability to mine enough minerals to replace all current electrical demand with renewables. We're talking trillions of dollars, the biggest project in human history. And that doesn't account for how our electricity usage grows year over year.

On top of all that, the plankton in the oceans are dying off right now due to acidification. Without plankton, the oceanic food chain collapses. Without the ocean we're all fucked, oceanic life is most life on earth.

The best case scenarios here involve billions of deaths.