The 5th U.S. Data Center Sustainability & Energy Efficiency Summit is a two-day executive forum for the people responsible for powering, cooling and decarbonizing American digital infrastructure at a moment when every established assumption in the field has broken down. For a decade, Data Center sustainability ran on a settled playbook: drive PUE down, buy renewable certificates to cover annual consumption, publish a 2030 net-zero target, and report progress. AI-scale compute demand has dismantled all four pillars of that approach simultaneously. Efficiency gains have flattened. Annual certificate matching has lost credibility. Net-zero targets set in 2020 are now, for the largest operators in the industry, mathematically unreachable. And sustainability performance has stopped being a reporting exercise and become the factor that determines whether a project receives permission. Held in Dallas, at the centre of the most contested and fastest-growing data center market, the summit will address the central question facing the industry: how do we power, cool and scale the AI data center boom sustainably? Exploring the future of clean energy & nuclear solutions, water resil- ience, next-generation cooling, heat reuse, low-carbon construction and intelligent operations, the event will bring together leaders shaping the next era of sustainable digital infrastructure.