One approach to understand adaptation benefits for risk reduction is to contrast projected impacts for the same climate and development conditions but different levels of adaptation. For example, global-scale coastal protection studies considering both RCPs and SSPs suggest that, under a given RCP, the total flooded area may be reduced by 40% by using 1-m height dykes, compared with a no-adaptation baseline . The global cost of SLR over the 21st century can be lowered by factor of two to four if local cost-benefit decisions consider migration an adaptation option, in addition to hard protection . Under a low-warming scenario, it is estimated that adaptation  could reduce the total number of people at risk of hunger globally by about 4%, and by about 10% in a high-warming scenario . Impacts on heat-related mortality would be cut from 10 to 7 deaths per 10,000 people yr-1 in 2100 by adaptation actions beyond those assumed to be driven by income growth . In a regional example, proactive adaptation efforts on infrastructure  in Alaska, USA, could reduce damage-related expenditure by 45% under medium or high warming .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report