In 2023, humanity experienced the hottest summer in history. United Nations Secretary General Antonio Guterres expressed his sense of crisis: “The era of global warming has ended; the era of global boiling has arrived.” The threat to human survival from climate change has become an immediate crisis. Along with efforts toward decarbonization, a new challenge has emerged: addressing the “water problem” associated with the advancement of digitization. In the background is the construction of data centers, which are expanding rapidly worldwide.