The DIMA model was used to estimate forest-related land-use changes, including reforestation, afforestation, and deforestation and forest management as triggered by carbon sink and bioenergy incentives. It operates on a half-degree grid basis on the global scale. The main output used in MESSAGE V.4 are dynamic, spatially explicit sink enhancement activities conditional on prices for CO2 and bioenergy (Rokityanskiy et al. 2007). Model outputs were incorporated into MESSAGE using a soft-linking approach, i.e., they are used as exogenous inputs in the form of sink enhancement potential supply curves to MESSAGE to incorporate price-quantity trajectories calculated with the DIMA model.
Overall, modeling results from DIMA indicate that carbon sequestration policies could contribute to a significant part of the global portfolio of efficient climate mitigation policies, dependent upon carbon prices. Many of the early estimates may have been biased because they focused on average and not marginal costs (Stavins 1999, Plantinga et al. 1999). While these two studies more accurately capture the increasing price of converting land into forests, they did not consider alternative forestland management options, such as changing rotation lengths and changing management intensity.
DIMA model parameters and speeds of their potential change over time were chosen from within historical ranges in such a way that close replication of the baseline development for revised SRES projections is achieved. The historical values of these parameters and the relevant speeds of change are provided by Sathaye et al. (2003, 2005). A more detailed description of the coupling between MESSAGE and DIMA can be found in (Rokityanskiy et al. 2007).