While unprecedented can mean unexpected or out of the norm it can also mean never before seen/done. So technically yes every point on the predictable upwards trendline is an unprecedented amount when we reach it in actuality.

Even assuming that HN readers may feel the word is emotive it's pointless to quibble about it when realistically any discussion about the details of climate change are going to be more emotive with such clinically correct terms as "climate refugees", "ocean acidification", "deadly heatwaves", "longest cyclone season", "3rd once in a century storm in the last decade".