Very high risk implies limited ability to adapt. Adaptation potential not only differs across sectors and regions, but also occurs on different time scales depending on the nature and implementation level of the adaptation option under consideration and the system in which it is to be deployed. The costs of adaptation actions that would be needed to offset projected climate change impacts for major crop production are projected to rise once global warming reaches 1.5℃ . It has been estimated that the number of additional people at risk of hunger with 2.0℃ global warming could be reduced from 40 million to 30 million by raising the level of adaptation action , but beyond this level of warming residual impacts are projected to escalate . Chapter 5 assessed the potential of existing farm management practices to reduce yield losses, finding an average 8% loss reduction in mid-century and 11% by end- century , which is insufficient to offset the negative impacts from climate change, particularly in currently warmer regions . The literature indicates that, globally, crop production may be sustained below 2.0℃ warming with adaptation, but negative impacts will prevail at 2.0°C warming and above in currently warm regions . Importantly, residual damage  is projected to rise around 2.0°C global warming . Evidence of constraints and limits for food, fibre and other ecosystem products for the different regions is evident for the various regions  indicating limited ability to adapt. Adaptation costs are also higher relative to GDP in low-income countries, for example for the building of sea dikes .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report