Time steps

In global MESSAGEix models the time horizon of 2010 to 2110 is generally subdivided into 5 or 10-year periods, using 2010 or 2015 as the base year. The 2020 period is partly calibrated so far, some recent trends are included in this time period, but some flexibility remains. The reporting years are the final years of periods which implies that investments that lead to the capacities in the reporting year are the average annual investments over the entire period the reporting year belongs to. In recent model versions, the model has been calibrated to 2015 running with 5-year modeling periods until the middle of the century (2020, 2025, 2030, 2035, 2040, 2045, 2050, 2055, 2060) and 10-year periods between 2060 and 2110.

MESSAGEix can both operate perfect foresight over the entire time horizon, limited foresight (e.g., two or three periods into the future) or myopically, optimizing one period at a time (Keppo and Strubegger, 2010 [41]) (see Mathematical Specification for more details). Most frequently MESSAGEix is run with perfect foresight, but for specific applications such as delayed participation in a global climate regime without anticipation (Krey and Riahi, 2009 [46]; O’Neill et al., 2010 [68]) limited foresight is used.

GLOBIOM models the time horizon 2000 to 2100 in 10 year time steps (2000, 2010, 2020, 2030, 2040, 2050, 2060, 2070, 2080, 2090, 2100) with the year 2000 being the base year of the model. The model is recursive-dynamic, i.e. it is solved for each period individually and then passes on results to the subsequent periods. The linkage between MESSAGEix and GLOBIOM relies on the model results of the periods 2020 to 2100.