The paper first presents evidence from the engineering literature on air and water pollution control, which shows that, when the pollution abatement technologies are in place, large reductions in pollution have been achieved at costs that are small relative to the costs of production. A simulation model is then developed to study the effects of technical progress on pollution abatement, and applied to particular cases in developing countries. The results are compared with the projections of an environmental Kuznets curve: they reproduce the latter if policies were not to be introduced until per capita incomes reached levels comparable to those of the industrial countries when they first introduced their policies; but show dramatically lower and earlier peaks if policies were to be introduced earlier. The conclusion is shown to apply more generally, and it is argued that developing countries can aspire to addressing their environmental problems at a much earlier phase of development than the industrial countries before them.