MAGICC - Model for the Assessment of Greenhouse Gas Induced Climate Change. MAGICC6 is a reduced-complexity climate model that attempts to synthesize current scientific understanding about many different gas-cycles, including the carbon cycle, climate feedbacks and radiative forcing. The strength of MAGICC is that it is sufficiently flexible to be able to closely emulate the large and complex climate models, sufficiently physically based to allow credible interpolations and indicative extrapolation near the calibration range. Furthermore, MAGICC6 is fast. That is an advantage, particularly for producing probabilistic projections for new emission scenarios, a process that is computationally unfeasible with the complex climate models. Thus, with due respect, if the question is whether MAGICC6 is the best method around to synthesize a whole range of climate and carbon cycle knowledge for probabilistic projections over the 21st century and beyond, we are inclined to say ”yes”. Thus, MAGICC6 aims to complement, rather than replace, any complex climate models (simply because MAGICC6 is closely calibrated towards these ”big brothers”).