September 2020 marks 30 years since a group of emboldened mayors asserted the need for local action to advance global sustainability. This meeting at the UN was the first "city climate" gathering and resulted in the founding charter of the International Council for Local Environmental Initiatives, now ICLEI Local Governments for Sustainability. Today, the advocacy on behalf of cities, towns, and regions continues around climate, biodiversity, health and equity action — with important opportunities for U.S. local governments over the coming year. California State Senator Nancy Skinner, an original architect of the ICLEI Charter, researcher Ben Leffel, and ICLEI Director of Global Policy Yunus Arikan, provide a look into how U.S. cities counties continue to assert their leadership: past, present, and future. ICLEI is the focal point for the LGMA at the UNFCCC.