During its 20 years as an OECD member country, Korea has shared many good practices with its peers. It has championed green growth at the OECD, as well as establishing the Global Green Growth Institute and hosting the Green Climate Fund. This third OECD Environmental Performance Review of Korea assesses the country's progress in achieving its environmental policy objectives since the last review, carried out in 2006. Korea has been one of the fastest growing OECD economies over the past decade, driven by a large export-oriented manufacturing sector. However, growth has come with high pollution and resource consumption. With increasing energy demand, greenhouse gas (GHG) emissions have risen significantly and air pollution remains a major healthconcern. Despite impressive improvement in wastewater treatment, diffuse pollution increasingly affects scarce water resources. Urbanisation and industrialisation are also putting considerable pressure on biodiversity. Environmental challenges are exacerbated by Korea's population density, the highest in the OECD. Access to environmental goods and services and exposure to environmental risk vary significantly by region. To tackle these challenges, Korea has invested considerable effort in improving environmental management, for example by introducing strategic environmental assessment, reforming the environmental permitting system and strengthening air and water quality standards. Korea introduced the world's second largest emission trading scheme and remains one of the most innovative countries in climate change mitigation technology. Yet, coal is set to remain a core part of the energy mix, and road transport continues to be supported as the dominant form of mobility. Energy prices and taxes do not reflect the environmental costs of energy production and use. The Review emphasises that Korea needs to align its energy and climate policies to reduce GHG emissions by 37% below business-as-usual levels by 2030, as pledged at the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change in Paris.