2.4. Estimation of impacts
The estimation of impacts is essential for evaluating whether policies resulted in an abatement of the damage to the population, ecosystems and property produced by air pollution. The ability to describe these im- pacts is one of the most important advantages of relying on IA tools for the evaluation of the two decades of policy making in Spain. The follow- ing sections are dedicated to the description of the methodological ap- proaches incorporated into AERIS for the description of such impacts.