Sequestering Carbon in “Wood Vaults”

The chance discovery of a preserved tree that last saw the light of day when the Babylonian king Hammurabi walked the Earth has inspired a new method of low-cost carbon storage.

Ironically, the tree — which lived in approximately 1750 B.C.E.— was found buried in Saint-Pie, Quebec, during a pilot study of burying wood in order to sequester carbon and keep it out of the atmosphere. A new chemical analysis of the tree found that it was nearly perfectly preserved over the course of 3,775 years — evidence, the study authors believe, that this method of “wood vaulting” could keep carbon underground for significant periods of time.

“Carbon loss was less than 5%,” says study author Ning Zeng, a professor of atmospheric and oceanic science at the Univ. of Maryland. “It’s a really critical datapoint which tells us that if we intervene by actively burying wood in these conditions, you are guaranteed to be able to preserve the wood for thousands of years,” he adds.

Trees are a carbon sink, meaning they take up carbon from the atmosphere as part of the natural cycle that keeps atmospheric carbon relatively stable in the absence of excess greenhouse gas emissions. But trees decay relatively quickly, meaning they don’t sequester this carbon for long enough to meaningfully reduce greenhouse gas...