The upshot is that the transition to renewal energy sources and away from coal has had a marked impact on climate change if the models are correct. We’re no longer tracking in a worse-case scenario. It’s more like a middle-of-the-road-to-hell scenario. In other words, it’s not great, but it would’ve been hotter if we’d not done anything.
So what should our takeaway from all of this be? First, there is some good news here. The world is no longer heading toward the worst-case outcome of 4C to 6C warming by 2100. Current policies put us on a best-estimate of around 2.6C warming.
At the same time, a world of 2.6C by 2100 is still a giant mess to leave to the future, including today’s young people, who will live through that, and warming continues after 2100 in these current policy scenarios. Climate system uncertainties mean that we could still end up with close to 4C warming if we get unlucky with climate sensitivity and carbon cycle feedbacks.
Ultimately, we’re going to need some kind of large scale CO2 removal technology to cool the planet back down. Nobody quite knows what that is yet, but humans are pretty bright creatures so I’m actually optimistic that we’ll find something. I doubt it’ll happen before a lot of the world is close to uninhabitable, though.