Using an overlapping generation model à la Blanchard (1985) with human capital accumulation, this article demonstrates that the influence of environment on optimal growth in the long-run may be explained by the detrimental effect of pollution on life expectancy. It also shows that, in such a case, greener preferences are growth- and welfare-improving even if the ability of the agents to learn is independent to pollution and utility is additively separable. Finally, it establishes that it is possible to implement a win-win environmental policy.