When it comes to influencing climate change, the world's smallest ocean punches above its weight. It's been estimated that the cold waters of the Arctic absorb as much as 180 million metric tons of carbon per year—more than three times what New York City emits annually—making it one of Earth's critical carbon sinks. But recent findings show that thawing permafrost and carbon-rich runoff from Canada's Mackenzie River trigger part of the Arctic Ocean to release more carbon dioxide (CO2) than it absorbs.
