The message is two-fold:
1. Not only are we fucked, but it’s coming much sooner than we expected. It’s coming in the first half of this century, not the second. By 2050 life for all but the simplest and most well-protected species on this planet will almost certainly be impossible, except for small numbers in a few marginal areas.
2. The whole issue of mitigation and the need for activism is now more-or-less moot. Even if we were to collectively and massively change our behaviour starting tomorrow, it would only delay collapse by a few years, and quite possible make the collapse even more catastrophic. Until recently there was at least a chance that perhaps a combination of behaviour change and the reduced availability of cheap fossil fuels might combine to pull us back from the brink, or at least make a much-changed and simpler life possible for a much smaller population of humans and other creatures. That chance is gone.
And here's our collective global mission impossible:
If we want to not die, then we need to stop doing the things that are going to kill us… We need deindustrialization, and we need to wring the bloody neck of capitalism, before hanging it, drawing it, quartering it, and setting the remaining bits of its corpse on fire to make sure it can’t rise from the dead like the unholy zombie that it is… This is all to say, I can’t fight my enemies and my allies at the same time. Liberals, lefties, environmentalists and everyone else who purports to give a damn has to give up on being capitalism apologists who somehow think we can keep this gravy train of mass consumption going.