Undersea Permafrost Is a Huge Wild Card for the Climate

Scientists used torpedo-shaped robots to map the Arctic seafloor with sonar, revealing massive sinkholes of thawed permafrost. This story was originally published by Wired and is reproduced here as part of the Climate Desk collaboration. Around 20,000 years ago, the world was so frigid that massive glaciers sucked up enough water to lower sea levels by 400 feet. As the sea pulled back, newly exposed land froze to form permafrost, a mixture of earth and ice that today sprawls across the far north. But as the world warmed into the climate we enjoy today (for the time being), sea levels rose again, submerging the coastal edges of that permafrost, which remain frozen below the water. It's a huge, hidden climate variable that scientists are racing to understand.