The Arctic Is Getting Greener—But That’s Not Good News

https://www.nature.com/articles/s43247-025-02768-2As our planet heats up, the Arctic is getting greener. I just read an interesting study about how all those new plants—especially shrubs—could be changing what’s going on underground in the frozen soils known as permafrost.

For four years, scientists in northern Greenland ran an experiment to see what happens when frozen soil is exposed to air and mixed with dead plant bits, called litter. They were trying to picture what the Arctic might look like as plants keep spreading north. The results were pretty wild: that extra plant material actually changed the DNA of the tiny microbes living in the soil!

Those microbes got busier—and hungrier—breaking down old carbon and nitrogen, which caused them to release a lot more greenhouse gases. In fact, when permafrost thawed and got extra plant litter, it gave off up to eight times more carbon dioxide than frozen soil alone. So as the Arctic turns greener, the ground itself could flip from storing carbon to giving it off.

Why Should We Care About Arctic Greening?

The Arctic is a long way away, so why should we care? Because what happens in the Arctic doesn’t stay in the Arctic–it affects the whole planet.

Permafrost holds about 1,700 billion tons of carbon—more than twice what’s currently in the air. Scientists have long warned that as it thaws, it could release carbon dioxide and methane, speeding up global warming. This study suggests that the process might get even faster when new plants grow on top of it.

For years, people thought “greening” the Arctic might help by letting more plants pull in CO₂ during photosynthesis. But this research shows the opposite might happen. The extra plant litter acts like a feast for microbes, which then eat up the ancient frozen carbon and send it back into the atmosphere.

The study also found that microbes are grabbing more nitrogen for themselves, leaving less for plants. That could make the soil less fertile over time—even while it releases more greenhouse gases.

What’s Going On Underground?

I’ve written before about some of the hidden impacts of climate change—from stronger clear-air turbulence to marine heatwaves, toxic algae, and the spread of bacteria like Vibrio. But there’s another one we don’t think about much: what’s happening beneath the frozen Arctic ground.

As the Arctic warms, the frozen soil—called permafrost—starts to thaw, waking up billions of tiny microbes that have been asleep for centuries. These microbes break down old plant and animal remains trapped in the ice. In doing so, they release carbon dioxide and methane, two powerful greenhouse gases.

And when new shrubs move north, their fallen leaves add even more “food” for these microbes. With this fresh carbon to munch on, they multiply quickly and breathe out even more gas—speeding up global warming even further.

Scientists found that certain enzymes—special proteins that help break down tough plant material—became much more active. That means decomposition speeds up. More decomposition = more carbon released = more warming.

This creates a feedback loop:

• Warmer air thaws more frozen soil.
• Thawed permafrost wakes up more microbes.
• Microbes release more CO₂ and methane.
• Those gases trap more heat and warm the Earth even faster.

The Big Picture

This new study shows that Arctic “greening” isn’t just about new plants—it’s also changing the biology of the soil. What was once a frozen storage locker for ancient carbon is turning into a living system that releases it.

In short, as the Arctic wakes up, it could actually make global warming worse. The world of microbes and plants beneath the surface holds big clues about what’s coming—and understanding it can help us better predict how our planet will change in the years ahead.