This paper presents an overlapping generations model in which: (i) firms create emissions as by-products of production; and (ii) tax revenue from the working young is transferred to the retired elderly as pay-as-you-go pension benefits. The paper focuses on a replacement ratio, which measures the proportion of after tax work earnings replaced by the public pension, and considers a replacement ratio neutral reform in which the newly introduced environmental tax is devoted to cutting the social security tax, keeping the replacement ratio unchanged. It is shown that the reform may improve growth, environmental quality and the nonenvironmental utility of every generation.