Losses in terrestrial and marine biodiversity increase substantially beyond 1.5°C of warming . Section 16.5.2.3.2  finds that substantial biodiversity loss globally, abrupt local ecosystem mortality impacts, and ecological species disruption are all projected at global warming levels below 3ºC, with insular systems and biodiversity hotspots at risk below 2ºC . Insects play a critical role in providing vital ecosystem services that underpin human systems, with major losses of their climatically determined geographic range at 2℃ warming implying adverse effects on ecosystem functioning. Consistent with the transitions presented here, a similar burning ember developed in Chapter 2 assessed a transition from moderate to high risks globally for marine and terrestrial biodiversity  beginning between 1.0°℃ and 2.0°℃ warming .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report