Pretty shocking. It would appear we're much further along the trajectory than was once assumed. I think it comes down to the whole thing being far more complicated than the various models used allow for. Granted, this also means that a reversal could possibly happen more easily than models allow for, but I'm afraid that's wishful thinking because that would at least require a committed, coordinated, global effort, and countries can't even coordinate gun control or whether or not to leave the EU, much less anything outside their own borders. (Well, New Zealand got it together pretty quickly on gun control. The US can't even decide if teens should be allowed to buy assault rifles or not.)

As an example of complexity, I read a while ago about how a decrease in pollution, something we all want and that would be a result of and result in lowering greenhouse gasses, would at this point increase global warming. See https://www.scientificamerican.com/article/cleaning-up-air-pollution-may-strengthen-glo... (I haven't read the whole article.) So we're walking such a fine, delicate line, trying to get something back into balance that earth had kept in balance until we screwed everything up. The complexity of the ecosystem, I think, is far greater than we are able to comprehend. We think we're so fucking smart with all our science. A little knowledge is a dangerous thing.

EDIT: Yes, the article does indeed echo what I'd read earlier. From the end:

""I think we need to have more variety in those projections, since even matching up the real world today with the emissions projections from 2000 that we used last time shows a significant mismatch," said Schmidt, the NASA scientist (who was not involved with the new research), in an email to E&E News.

What remains clear, though, is that the full extent of human-caused global warming is still revealing itself—and the future may be more severe than the past would seem to suggest."