Financial constraints are the most referenced barrier to health adaptation and so scaling up financial investments remains a key international priority  . AR5 estimated the costs of adaptation in developing countries at between USD 70 billion and USD 100 billion annually in the year 2050, but these are likely to be a significant underestimate, particularly in the years 2030 and beyond . National surveys conducted by WHO identified financial constraints as a major barrier to the implementation of health adaptation priorities . Novel research drawing on global financial transaction data suggests that in 2019, global financial transactions with the potential to deliver adaptation in the health and healthcare sector reached USD 18.4 billion, driven by transactions in high- and upper middle- income countries, with investment in Africa, Southeast Asia and the eastern Mediterranean mostly stagnant .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report