It's the "final warning" in the sense that the next report is going to be issued in 2030. By that time, 1.5C will be be inevitable. We may not have hit the temperature yet, but only because it takes a few years for the temperature to respond to the greenhouse gases already in the atmosphere.<p>Which is to say, if we don't change right now, then when the next report comes out, we will already have enough CO2 in the atmosphere to be at 1.5C -- even if we stopped burning fossil fuels absolutely and utterly.<p>I'm really not sure how much such a warning can accomplish, after decades of having been ignored in the past. I've been treating 1.5C as a fait accompli already.<p>The problem for me is less about the actual temperature, or even the disasters that will come of it, but what it does to American culture right now. The whole world has failed to solve the problem, but I think America was the lynchpin. We deny that the problem exists, making it much harder for the rest of the world to summon the will to spend money to do it.<p>But in America, that has cost us our relationship to science. Any HN discussion is sure to be filled with criticisms of the scientists, many of them insisting now that this is all some kind of leftist power trip. That has utterly destroyed not just our ability to use science for any national ends, but an implacable, violent hostility between political groups.<p>Climate change is only one part of that culture war, but it is a particularly strong example. The climate conspiracy theorists are simply wrong, just plain factually on the face of it. It's not a matter of values, or interpretation, or conflicting scientific models. There's a right and a wrong answer, and if even that turns to bitter hatred, how an we possibly resolve any genuine differences of opinion?