CMIP6 climate models project drying in the Amazon-especially in June-July-August, irrespective of future forcing scenario, but which increases with GSAT/higher scenarios . For higher GSAT levels, Burton et al.  explore different forcing scenarios and found, regardless of scenario, burned area increases markedly with GSAT. New understanding of the role of vegetation stomata will act to exacerbate this drying . A transition to high risk of savannisation for the Amazon alone was assessed to lie between 1.5ºC and 3ºC with a median value of 2.0°C. A mean temperature increase of 2°C could reduce Arctic permafrost area ~ 15% by 2100 . Chapter 2 has assessed ecosystem carbon loss from tipping points in tropical forest and loss of Arctic permafrost, and finds a transition from moderate to high risk over the range 1.5℃ to 3ºC with a median of 2℃ . Its assessment of the transition from high to very high risk is located over the range 3-5℃  based on the potential for Amazon Forest dieback between 4℃ and 5℃ temperature increase above the pre- industrial period .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report