Consider many countries whose non cooperative emission strategies end up in an inefficient global pollution level. The regulator is interested in implementing an efficient (Pareto optimal) profile of individual emissions, but this normally requires some private pieces of information like ”how much of its individual goals each country is willing to give up to enjoy a decrease of global pollution?”. Those pieces of information are typically not known from the regulator. Given the regulator limited knowledge, we design an iterative mechanism that converges to a Pareto optimal profile of emission and such that at each step no single country experiences a decrease of utility. The relative advantage of this mechanism over previous ones ([1, 2]) lies in its simplicity and its incentive properties.