Greenhouse Gas Emissions

In 2005, Yale became one of the first universities to commit to reducing its greenhouse gas emissions, pledging to cut emissions 43% by 2020. Yale achieved that goal in 2020 and has since committed to achieving zero actual carbon emissions by 2050 with an interim goal to reach net-zero emissions by 2035.

In 2015, Yale expanded its greenhouse gas emissions boundary, establishing a new baseline for university goalsetting. As of 2025, Yale has reduced net emissions by 28% and gross emissions by 7% from that baseline, despite continuous growth in campus size and energy intensive spaces.

Our 2050 zero-emissions goal encompasses scope 1 and 2 emissions and aligns with The Climate Registry’s standards for verification, which require rigorous and transparent accounting by a third party.

How was this 28% reduction achieved?

Yale has made significant investments in energy-conservation projects and operational modifications to infrastructure to reduce energy use, energy costs, and greenhouse gas emissions. Since 2015, Yale has built and renovated a large quantity of campus spaces to make them more environmentally sustainable in support of the university’s academic mission and sustainability goals.

 Yale’s gross emissions increased 3% between 2024 and 2025 due to campus growth, higher energy use in buildings not served by Yale’s power plants, rising energy consumption at Yale-New Haven Hospital, and increased computing demands. Gross emissions are still down 7% since 2015 due to multi-year efficiency projects.

With 2050 in mind, Yale is prioritizing on-campus emissions reductions through transformative, long-term projects. After two decades of optimizing centuries-old buildings and utility systems, we are now developing new clean-energy infrastructure for the future. Over the past five years, we have planned for complex, district-level projects that will fundamentally shift our energy management approach, in time delivering substantial savings rather than incremental reductions.

Despite the slight increase in gross emissions in 2025, Yale’s net emissions have not increased since 2020 thanks to on-campus emissions reductions and the purchase and retirement of high-quality, verified carbon offsets.

Learn more about carbon offsets and Yale’s approach to them.