Fighting the great challenges in large-scale environmental modelling

High pollution levels may cause different damages. Therefore, critical levels have been established by different authorities (such as WHO, EU and environmental agencies in many countries). The critical levels should not be exceeded in the efforts to avoid damaging effects from harmful pollutants. Mathematical models can potentially be very useful tools when efficient measures have to be taken in order to bring the pollution levels under the prescribed critical levels and/or to keep them there. However, there are still many unresolved problems connected with the application of mathematical models in the attempts to design reliable and robust control strategies for reduction of the pollution to the critical levels and/or for keeping the pollution under the prescribed critical levels. Three of the unresolved problems, which are very challenging, will be discussed in this paper.