*eerrkkkk* (braking sound) Sorry to be pedantic about the opening paragraph, but you're a prominent climate writer so it's got to be said: Framing the predicament like this is fallacious, a false binary. When people read / hear "Even if we did everything now to stop fossil fuels etc. we would still have X amount of warming and weather calamity" and that "the only option is to adapt" this promotes a business-as-usual mentality. "Oh well," people say (doomers especially), "nothing we can do."

In reality, every action is meaningful, even if we don't have the fine-tuned calculus (most carbon footprinting is dubious) to assure us of our contributions. But we do know that every .1 degree above average global temperatures, 140 million people are exposed to dangerous heat. And we can extrapolate from that study that X amount of people are exposed to floods, droughts, and other calamities.

So everything we do relating to our use of carbon / fossil fuels / dense energy indeed matters. Mitigation is always possible. Adaptation is inevitable, yes, but mitigation buys time for that adaptation. Be it migration, fortification, preparation, or otherwise.