Climate Corner: Leave it to beavers

Oct 22, 2022

Linda Eve Seth

“The beaver told the rabbit as they stared at the Hoover Dam: ‘No, I didn’t build it myself, but it’s based on an idea of mine.’” — Charles Hard Townes


If you know any facts about beavers, it’s probably that the toothy rodents are known for being industrious. Most famously, they build dams. These giant structures made of sticks, stones, and mud can reach heights up to 10 feet and lengths averaging 20 feet. The biggest one ever found was in Alberta, Canada, and could be seen from space. As reported in 2010, it was a half- mile long.

As it turns out, these natural engineers may well be humans’ natural allies in efforts to confront climate change.

Beaver dams completely alter the landscape, flooding the surrounding area, and creating wetlands. It’s one reason beavers have often been considered pests that can cause serious damage when they build dams too close to homes or roads.

Scientists have understood beavers’ importance for decades. Studies are finding that beavers play a vital role in dampening the effects of the worsening climate crisis, especially in areas prone to fire, drought, and heat waves.

These web-footed, fat-tailed, amphibious rodents help countless other critters survive a heat wave. They not only drench certain landscapes in cold water but also help cool the air. They help make forests and grasslands less likely to burn.

It’s increasingly clear that these animals help safeguard ecosystems against the worst of climate change. Beavers are very much wildlife heroes in a warming world. We know that beavers build dams. But these structures are so much more than just a pile of sticks laid across a stream. They’re hydrological wonders.

Dams form ponds, widen rivers, and create wetlands, building all kinds of aquatic habitats that many other animals like birds and frogs rely on. Beavers are the ecosystem engineers of the animal world.

Because every ecosystem is unique, beavers can have different effects on the environment depending on where they are located.

More than just spreading water around, beavers’ dams also help cool it down. Dams can deepen streams, and deeper layers of water tend to be cooler. As streams run into these structures, they can start to carve into the river bed. So, there can be, for example, a six-foot-deep pool behind a three-foot-high beaver dam.

Dams also help force cold groundwater to the surface. Made of sticks, leaves, and mud, dams block water as it rushes downstream, forcing some of it to travel underground, where it mixes with chillier groundwater before resurfacing. Scientists tell us that is really important for a lot of temperature-sensitive species like salmon and trout.

The presence of beaver dams can also help chill the air. As all that water in a beaver habitat starts to evaporate, the adjacent air cools down. Turning water into vapor requires energy, and some of that energy comes from the heat in the air. It essentially functions like an AC system sitting out there in the landscape, keeping the air temperature, 10 or 15 degrees cooler, which, scientists point out, is a sizable difference.

Beaver damming also plays a significant role in protecting surrounding vegetation during wildfires. By helping replenish the groundwater that humans rely on, beavers’ dams also provide insurance against droughts.

We need smart, out-of-the-box ways to defend against the worst effects of climate change. Instead of just relying on human-made technologies and infrastructure, we can also restore species like beavers to the landscape, working with nature, instead of against it. We need to make our cities and towns much more resilient, not unlike a habitat filled with beaver dams.

Enlisting beavers in the effort could be one such way forward. They are, after all, the only other species anywhere nearly as capable as humans at transforming a landscape.

Beavers aren’t like other animals. In captivity they have to be groomed daily and nurtured or they fail to thrive. They have to have a constant person to care for them and lots of time spent with them. Kinda like Earth herself.

Until next time, be kind to your Mother Earth.


Linda Eve Seth, SLP, M.Ed. is a mother, grandmother, concerned citizen and member of MOVCA.