What's to achieve by saying we've blown it - that people spark a revolution, or give up trying ? Some of us have been trying for decades, others have been denying for decades, doubt either set gives up.

The original goal the UNFCCC (Art2) was defined in terms of concentrations, so in 1990s diplomats were arguing about 350, 450, 550ppm - 350 being the arbitrary level at the time of the first global climate conferences. I am partly responsible for pushing the shift towards a temperature target, arguing that it would reduce the uncertainty for climate impacts (although increasing it for emissions pathways), but it was extremely hard to get US, China, India to sign up even to <2ºC (COP15). As climate impacts projections got better quantified the most vulnerable countries (mostly African and small islands - together they are many in UN... ), later joined by EU, insisted on trying for a lower number, but we had already passed 1ºC, so we got 1.5º as a compromise in Paris. That 0.5ºC might make the difference as to whether we save Greenland and WAIS, or many ecosystems and food systems. Nevertheless the decimal places are still arbitrary (also influenced by choice of base period, and negotiating in ºC not ºF ), no study quantified impacts vs efforts sufficiently to distinguish a threshold at 0.1ºC accuracy. What matters is that people understand the huge inertia in the systems, in heat and carbon transfer in the ocean, ice and biosphere, also in demographics and social systems. I made an interactive model - SWIM to help explore this. We have to keep trying.

The key thing in there is the paper link. Basically we won't breach the treaty number with a single year above 1.5C; it takes bringing the long term average abive that since its not too unlikely that we'll see one year above, then some years below just because of how much natural variability is in the climate system

It's not nearly as common today, but occasionally someone will still make a comment about global warming and scientists being wrong. And I'll get to say, "yes, they were wrong. Average temperature is increasing faster than the initial forecasts." IPCC 2018 report didn't look the greatest, and it included effects of a carbon sequestering process that hasn't been invented yet.

At this point, we know the world will look different in 50 years (where water is, where crops are grown, where floodplains are). Avoiding major changes is now impossible. BUT, it's a continuum. We still have control over it being a new struggle to overcome vs a major catastrophe.

I was reading lots of buzz about the IPCC report and had an opportunity to visit a glacier in Alberta. On the hike to the glacier, they had signs showing where the glacier was over the years. At first, there would be a sign saying "1890" and 100 meters farther, a sign reading "1920". Then it was "1940" and a hundred meters away "1960". Then it became "2004" and 100 meters away "2008". I forget the exact spacing, but it was very obvious that the glacier is melting at an accelerating rate. That plus the IPCC report was my realization that climate change is happening, and we've passed the period where it's only observable on instruments. Most people are entering into the phase where it has real effects on our daily lives.

what is global warming? /s