Procedures used to match and adjust resolutions involve substantial technical difficulties and are of potentially large significance for the ultimate utility and credibility of assessment projects.
Atmospheric chemistry takes place fast and on a small scale.
Mismatch of resolutions can create problems even with the purely analytical exercise of providing an integrated description of the climate system. While aggregating fine-resolution results to coarser resolution typically poses no technical problems, going the other way is contentious and difficult. The need to change resolution can arise in an integrated assessment at several points. The first is re-aggregating emissions modeled along political boundaries into latitude bands or cells, to provide locational input to atmospheric chemistry models. This is normally accomplished by judgmental allocations, which are normally assumed fixed and hence abstract away from whatever shifts in regional population and economic activity may occur over time.