Study Finds Trees Growing Taller Due to Climate Change

Feb 26, 2021

New research out of West Virginia University says trees are now taking up more Carbon Dioxide than ever recorded. And because forests are the planet’s carbon sink, trees all over the world are actually growing larger to keep up with rising CO2. 

Mixed deciduous forest within the Monongahela National Forest in the Appalachian Mountains of West Virginia 2018
Credit Justin Mathias

What's known as the Gaia theory posits, earth is a self-regulating system with a positive feedback loop that somehow, keeps things in homeostasis or balance. 

“We know that CO2 has been building up since the industrial revolution,” says Richard Thomas, professor of biology at WVU. “There's been a 48% increase since then.”  

Thomas worked with Justin Mathias, a postdoctoral scholar at the university of California at Santa Barbara.

He says, the implications of these findings are extremely important, because “whether or not forests are taking up more carbon, globally, could have large cascading effects over ecosystems and large geographical areas.”

The authors point out, this could cause weather issues that would look different around the world, but it is the net global effect they are studying.  And what they found is, as the planet’s trees inhale --so to speak-- more and more carbon from the air, those trees are growing larger and larger, thanks to photosynthesis. And while this helps regulate climate to some degree, the problem still exists, says Mathias.

“We’re still emitting fossil fuels and greenhouse gases into the atmosphere. Had these trees not increased their photosynthetic rates and drawn down a little bit more of that CO2. It would be potentially warmer. It would contribute to a little bit more of the warming of our planet.”

So how tall might these trees have to grow to keep sucking up more CO-2 and how long can that system continue without riding off the rails?

“The real trade-off is in just how much land there is, where we can actually grow forests.”

Phil Radtke teaches Forest Resource Management at Virginia Tech and was not involved in this study

“The U. S. is a really good example of that. We are pretty much maxed out as to how much land we can possibly dedicate to growing forests.”

And it’s that way in much of the world.  “We have a lot of people and people need land for agriculture and for living and urban developments and such. So, it's really not feasible that we can just take millions and millions and millions of acres and set them aside for growing trees. Most of the places where we're growing trees and forest now are the only places left where we can really do that reasonably.

Radtke says all this shows why we need to protect our forests and keep them healthy so they can continue to take carbon dioxide out of the air.

“The trees taking the CO2 out of the atmosphere may ameliorate climate change. If the trees weren't there taking up CO2, it could exacerbate climate change.”   

This study on the unexpected role trees play in climate change is published in the Proceedings of the National Academy of Sciences