The Climate Challenge is an in-person role-playing UN climate change negotiations exercise. Through the simulation, participants get to explore the necessary speed and level of action that nations must take to address global climate change. The World Climate Simulation, from Climate Interactive, the MIT Sloan Sustainability Initiative, and the UMass Lowell Climate Change Initiative, is an in-person role-playing exercise of the UN climate change negotiations. Through the simulation, participants get to explore the necessary speed and level of action that nations must take to address global climate change.