Trees absorb carbon dioxide as they grow, but rather than just letting the forest sit there for 100 or more years, harvesting regularly and using the wood in place of steel and concrete that devour fossil fuels during manufacturing could significantly lessen atmospheric CO2, University of Washington researchers said.
"Every time you see a wood building, it's a storehouse of carbon from the forest. When you see steel or concrete, you're seeing the emissions of carbon dioxide that had to go into the atmosphere for those structures to go up," Bruce Lippke, a professor of forests resources, said.
Sustainably managed forests are essentially carbon neutral, researchers say. The gas trees absorb while growing eventually goes back to the atmosphere when, for example, a tree falls in the forest and decays, trees burn in a wildfire or a wood product goes to a landfill and rots.
The best approach for reducing carbon emissions, they said, involves growing wood as fast as possible, harvesting before tree growth begins to taper off and using the wood in place of products that are most fossil-fuel intensive.
"While the carbon in the wood stored in forests is substantial, like any garden, forests have limited capacity to absorb carbon from the atmosphere as they age," Lippke said. "And there's always a chance a fire will sweep through a mature forest, immediately releasing the carbon dioxide in the trees back to the atmosphere.
"However, like harvesting a garden sustainably, we can use the wood grown in our forests for products and biofuels to displace the use of fossil-intensive products and fuels like steel, concrete, coal and oil."