In the not so distant past, North America was home to one of the largest carbon sinks in the world. The great American chestnut forests — which ranged all the way from Maine to Mississippi and made up a full 25 percent of the tree canopy in the United States — were nearly immortal and massive in size, with the ability to sequester more CO2 than any other known hardwood tree.
Tragically a blight carried over from Asia at the turn of the century wiped out the entire species by 1950, an estimated 4 billion trees. Until recently the great American chestnut was nothing but a wistful memory, but recently researchers at the University of Tennessee created a strain of chestnut that is virtually identical to the original but incorporates disease-resistant genes spliced from the Chinese chestnut.
The U.S. Forest Service partnered with the University of Tennessee to the American Chestnut Restoration Project, and two years ago they planted the first batch of 500 seedlings in three states to test the viability of the new hybrid.
This month marks the two-year birthday of those saplings, and with their success several thousand more have been planted in an effort to slowly restore the chestnut forest. It will still be five to 10 years before anyone knows for sure if the trees remain resistant, but if they do, we may have on our hands a way to dramatically reduce the amount of CO2 being emitted into the atmosphere specifically from the U.S.
The chestnut can sequester as much as five times the CO2 of any other hardwood tree, some estimate 5 tons or more when full grown. And they grow quickly, inhaling massive amounts of carbon dioxide in the early phase of their life, making them a viable near-term carbon storage solution.