This paper provides the evidence on the short- and the long-run effects of the export product concentration on the level of CO2 emissions in 19 developed (high-income) economies, spanning the period 1962-2010. To this end, the paper makes use of the nonlinear panel unit root and cointegration tests with multiple endogenous structural breaks. It also considers the mean group estimations, the autoregressive distributed lag model, and the panel quantile regression estimations. The findings illustrate that the environmental Kuznets curve (EKC) hypothesis is valid in the panel dataset of 19 developed economies. In addition, it documents that a higher level of the product concentration of exports leads to lower CO2 emissions. The results from the panel quantile regressions also indicate that the effect of the export product concentration upon the per capita CO2 emissions is relatively high at the higher quantilcs.