EN-roads, a Climate Solutions Simulator

"En-ROADS is a transparent, freely-available policy simulation model that gives everyone the chance to design their own scenarios to limit future global warming. You can try your own experiments and assumptions, and get immediate feedback on the likely impacts. The simulation, developed by Climate Interactive, Ventana Systems, and MIT Sloan, runs on an ordinary laptop in a fraction of a second, is available online, offers an intuitive interface, has been carefully grounded in the best available science, and has been calibrated against a wide range of existing integrated assessment, climate and energy models."