The world’s hottest rainforest isn’t the Amazon. It’s not even in the tropics. It’s kept under glass in the desert of Southern Arizona. Biosphere 2, operated by the University of Arizona, was built 30 years ago as an experiment in space colonization, but now the ecosystems inside are perfect for climate change research. Unlike in the real world, scientists can control the elements—which is just what they did when they turned off the rain for two months. They’re tracking how carbon cycles through the enclosed rainforest during the drought. KNAU’s Melissa Sevigny reports, it’s a glimpse of what the world will look like in a hotter, drier future.