‘Earthworm Dilemma’ Has Climate Scientists Racing to Keep Up

Worms are wriggling into Earth’s northernmost forests, creating major unknowns for climate-change models.

The world’s boreal forests have been largely earthworm-free since the last Ice Age. But as invaders arrive and burrow into the leaf litter, they free up carbon and may accelerate climate change.  

The world’s boreal forests have been largely earthworm-free since the last Ice Age. But as invaders arrive and burrow into the leaf litter, they free up carbon and may accelerate climate change. Credit Cristina Gonzalez Sevilleja

By Alanna Mitchell

Cindy Shaw, a carbon-research scientist with the Canadian Forest Service, studies the boreal forest — the world’s most northerly forest, which circles the top of the globe like a ring of hair around a balding head.

A few years ago, while conducting a study in northern Alberta to see how the forest floor was recovering after oil and gas activity, she saw something she had never seen there before: earthworms.

“I was amazed,” she said. “At the very first plot, there was a lot of evidence of earthworm activity.”…