This book examines the presence of stochastic and deterministic convergence in ten series of greenhouse gases, aerosol precursors, and aerosols across 29 industrialized and emerging countries from 1820 to 2018. The author utilizes the Panel Analysis of Nonstationarity in Idiosyncratic and Common Components (PANIC) method for the empirical exercise. The analysis reveals strong evidence of stochastic convergence patterns in the series of log per capita emissions for black carbon, carbon monoxide, ammonia, non-methane volatile organic compounds, and nitrogen oxides, demonstrated by the existence of pairwise cointegration among individual series. Regarding deterministic convergence, the book provides compelling evidence of convergence in per capita emissions for black carbon, carbon monoxide, ammonia, non-methane volatile organic compounds, nitrogen oxides, and sulfur dioxide. There is also moderate evidence of convergence in per capita emissions for carbon dioxide, nitrous oxide, and organic carbon, and weaker evidence for methane emissions. The findings have significant implications for environmental policy, particularly in light of the observed deterministic convergence in emissions.