Different goals—like tracking contributions, projecting extremes, or assessing risks—require different emulator designs. We present a guide to help match methods to questions, showing how modelling choices affect what emulators can do. We also place existing tools like MESMER, an open-source emulator, in this broader context.

Using MESMER, we show how emissions from the wealthiest groups have disproportionately contributed to global warming—key estimates for climate justice debates.

Our research highlights how emulators can support fairer, more informed climate decisions.