Oh, who began an unprecedented fourth term as mayor of Seoul in July 2022, is well-known for his environmental leadership. He co-founded the Korea Federation for Environmental Movements and, as a lawyer, helped to establish the right to sunlight for the first time in South Korea’s history. 

As mayor, Oh has prioritised inclusive climate action to reach net-zero emissions by 2050, protect the safety of residents from the effects of climate change and improve equity. Among other measures, Oh has championed the Seoul Energy Welfare Civic Fund, which supports energy efficiency improvements among low-income households and other vulnerable populations, and connected young people hit hard by the COVID-19 pandemic to new climate and environmental jobs. 

Mayor Oh is committed to tackling air pollution, a major public health threat. In 2007, he developed the Clean Seoul 2010 initiative and in 2022, updated it as part of the Cleaner Seoul 2030, which includes various policy actions to cut air pollution emissions by 50% by 2030. Also high on Oh’s agenda is addressing emissions from waste. Under his leadership, Seoul is working towards a Zero Waste Seoul and striving to increase the plastic recycling rate to 80% by 2026. These efforts led to Seoul’s recycling earning the highest scores on the Global Power City Index ranked by the Mori Memorial Foundation in 2022.