Abstract: Greenhouse gas (GHG) accounting forms the basis of many climate policies. Responsible actors such as governments and corporations rely on GHG accounting—the practice of quantifying and reporting GHG emissions—to produce the emissions inventories that both inform and substantiate their efforts to mitigate climate change. For example, the United Nations Paris Agreement relies on countries' national GHG inventories to determine the progress they are making toward their climate pledges. And yet, our world is filled with "unaccounted-for" GHGs: emissions that are both measurable and caused by human activity but that are excluded from these institutional inventories. These emissions omissions may have profound consequences for the success of climate mitigation, because progress toward emissions reduction pledges can only be ascertained against GHG inventory trends. The wider the shortfall between institutionally accounted-for and scientifically estimated GHG emissions, the less effective climate policies will be. This lecture will explore how GHG emissions science does (or does not) get incorporated into law and policy—and how that may impact both people and climate progress.

Bio: Leehi Yona is the Gearns & Russo Faculty Fellow of Environmental Law and Assistant Professor of Law at Cornell Law School, specializing in environmental and climate change law. Her research focuses on legal frameworks for greenhouse gas accounting, climate justice, and regulatory strategies for transformative environmental governance. Professor Yona’s research examines interdisciplinary approaches to greenhouse gas accounting, addressing the challenges and gaps in current climate laws and policies and exploring ways to improve them. Her research has been published in leading journals such as the Harvard Environmental Law Review, Ecology Law Quarterly, Nature, Nature Sustainability, and the Journal of Environmental Science and Policy.

This event is presented as part of the 2026 Perspectives on the Climate Change Challenge Seminar Series:

• Most Mondays, Spring Semester 2026, 2:55-4:10 p.m.
• 155 Olin Hall & Zoom

This university-wide seminar series is open to the public (via Zoom), and provides important views on the critical issue of climate change, drawing from many perspectives and disciplines. Experts from Cornell University and beyond present an overview of the science of climate change and climate change models, the implications for agriculture, ecosystems, and food systems, and provide important economic, ethical, and policy insights on the issue. The seminar is being organized and sponsored by the Department of Biological and Environmental Engineering and Cornell Atkinson Center for Sustainability.