The environmental Kuznets curve after 25 years

The environmental Kuznets curve (EKC) has been the dominant approach among economists to modeling aggregate pollution emissions and ambient concentrations over the last quarter century. Despite this, the EKC was criticized almost from the start and decomposition approaches have been more popular in other disciplines working on global climate change. More recently, convergence approaches to modeling emissions have become popular. This paper reviews the history of the EKC and alternative approaches. Applying an approach that synthesizes the EKC and convergence approaches, I show that convergence is important for explaining both pollution emissions and concentrations. On the other hand, economic growth has a strong positive effect on carbon dioxide, sulfur dioxide, and industrial greenhouse gas (GHG) emissions, but weaker effects on non-industrial GHG emissions and concentrations of particulates. Negative time effects are important for sulfur and industrial and non-industrial GHG emissions. Even for particulate concentrations, economic growth only reduces pollution at very high income levels. Future research should focus on developing and testing alternative theoretical models and investigating the non-growth drivers of pollution reduction.