By Alexander Buck, IUFRO
Carbon sink or source? That’s a question scientists have debated for years regarding the world’s northern permafrost region and its boreal forests. A recent study shows that they are not just a sink—but a supersink—containing about half of the estimated global below-ground pool of organic carbon. It finds that boreal forests contain about twice as much carbon as that in the atmosphere, and much more than that stored in tropical forest ecosystems.*
What will happen to this carbon as permafrost melts and trees above topple? It’s not rocket science. These ecosystems are fragile—just look at the dwarfed trees and delicate lichens and feel the spongy ground below your feet. Indeed, studies have pointed out the relative ease with which carbon is released from the ground as thawing proceeds.
It is all food for thought—and for action—since the carbon stored in these areas has largely been ignored by climate change and mitigation scenarios. Moreover, the release of soil carbon is just one concern regarding the impacts of climate change on northern forests.
A report coordinated by the International Union of Forest Research Organizations (IUFRO) released last April revealed that forests’ roles as sinks is “at risk of being lost entirely” to climate change-induced environmental stresses. Higher temperatures—along with the prolonged droughts, more intense pest invasions, and other such plagues that will accompany climate change—could lead to considerable forest destruction and degradation. And this damage could significantly increase global carbon emissions, further exacerbating the greenhouse effect. Talk about feedback!
We do need to better to understand just how climate change will impact northern forests and the options for adaptation and mitigation of these effects. But experts say the challenge to policy makers is that they must act even in the face of imperfect data because “climate change is progressing too quickly to postpone action.”
*C. Tarnocai and J.G. Canadelle in Global Biogeochemical Cycles
Alexander Buck is the IUFRO Deputy Executive Director and Coordinator, CPF Global Forest Expert Panels