In Louisiana, the record rainfall that killed at least 11 people and flooded tens of thousands of buildings has been called a "1,000-year" event in some areas, meaning something like this only happens once a millennium. Just like climate change makes wildfires and drought more likely in California—and may make it more likely for viruses like Zika to spread—it also makes extreme rainfall and devastating flooding more common. In other parts of the state, experts have called it a 500-year flood. But those names probably don’t make sense in an era of climate change. "Warm air holds more water vapor than cold air, and we're warming up both the air temperature and we're warming up the oceans," says David Titley, a meteorology professor and the director of the Center for Solutions to Weather and Climate Risk at Penn State University. "Welcome to the future."