The extremes of climate change are wreaking havoc on the Mississippi. Over the past two months, this critical waterway has seen below average rainfall. In some places, water levels haven't been this low for more than 30 years. NPR's Debbie Elliot explains how that is helping the salty waters of the Gulf of Mexico push upriver, threatening municipal and commercial water supplies.Then Juanpablo Ramirez-Franco and Eva Tesfaye, of The Mississippi River Basin Ag and Water Desk, show us how life on the river can be just as hard when climate change produces too much water. In participating regions, you'll also hear a local news segment to help you make sense of what's going on in your community.Email us at considerthis@npr.org.