Climate adaptation finance involves mobilizing financial resources to support adaptation measures that enhance resilience and reduce vulnerability to climate change impacts, such as sea$-$level rise, extreme weather events, and shifting precipitation patterns. Delve into the theoretical foundations of climate adaptation finance, including funding mechanisms, investment criteria, and financial instruments. How do policymakers and financial institutions apply theoretical models of climate adaptation finance to mobilize resources, leverage investments, and support adaptation projects and programs in vulnerable communities and sectors$?$