Climate scientists flummoxed by unexpected bump in global temperatures
“We should have better answers by now.”
Maybe it's because climate scientists have been underestimating effects for decades so they didn't lose grants for looking alarmist.
Have they?
"In this case, their very specific prediction was that warming of between 1.5°C and 4.5°C would accompany a doubling of atmospheric CO₂" https://theconversation.com/40-years-ago-scientists-predicted-climate-change-and-hey-they-were-right-120502
Isn't the problem more that people have been reading that and assuming that it means 3°, not 'possibly 4.5°' ?
That said, the study there seems to assume that the effects are roughly linear, ie. that there are no tipping points.
That's the thing - if science is projecting something for the future nothing is 100% certain - so they have to widen the range in order to have a statement with a lower number that's "90% certain" even if there's a very high chance that it's going to be way worse