Why scientists have pumped a potent greenhouse gas into streams on public lands

Blacktail Deer Creek in Yellowstone National Park, seen here in a 2019 photo from the ecological study known as NEON, is one site where researchers have bubbled sulfur hexafluoride into the water. (NEON)

A massive ecological study that's happening across the United States, and which is designed to track the impact of long-term changes like a warming climate, is deliberately releasing a highly potent and persistent greenhouse gas in national parks and forests.

The gas, sulfur hexafluoride, is "the most potent greenhouse gas known to date," according to the Environmental Protection Agency. It's 22,800 times more effective at trapping heat than carbon dioxide, and lasts in the atmosphere for thousands of years.