In terms of hard limits, the rate and extent of climate change is critical as agriculture is climate-dependent and sensitive to changes in climate parameters. Poudel and Duex  document that over 70% of the springs used as water sources in Nepalese mountain agricultural communities had a decreased flow, and approximately 12% had dried up over the past decade. While there are some adaptation measures to address reduced water availability-such as the introduction of water- saving irrigation technology among Beijing farmers to alleviate water scarcity in metropolitan suburbs -these actions still depend on some level of water availability. If climate hazards intensify to the point where water supply cannot meet agricultural demands, hard limits to adaptation will occur.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report