Princeton University is positioning itself at the forefront of research that could help to throw the brakes on climate change, from its zero-carbon goals to the way it’s using the campus as a living laboratory. One person with a front row seat to all this is Forrest Meggers, a jointly appointed professor in Princeton’s architecture and engineering schools. He also directs Princeton’s C.H.A.O.S lab, which seeks to maximize the efficiency of heating and cooling systems. This month, as we celebrate Earth Day and PAW devotes its April issue to climate change, PAW asked Meggers for a tour through Princeton’s energy systems and a look at what’s coming next.