Proforestation: Addressing the Pressing Need to Conserve Mature, Mixed Forests

We need to plant trees, we need aforestation, but these methods take time to effectively sequester carbon. Proforestation conserves mature, mixed forests. It's the most effective way to naturally sequester carbon as quickly as possible.

A leading chemist and natural scientist is advocating what he calls "proforestation" as a means of capping greenhouse gas emissions and the rise in global mean temperature under the 1.5 degrees C set out in the Paris Climate Agreement.

William Moomaw helped found Tufts University Fletcher School's Center for International Environment and Resource Policy. He's served as the lead author for the UN Intergovernmental Panel on Climate Change's (UNFCCC) five reports. Essentially, Moomaw's "proforestation" boils down to leaving older and middle aged forests intact due to their ability to store atmospheric carbon at high rates, he explains in an interview with Yale Environment 360.

Moomaw says he's all for planting young trees, but mature forests sequester much more atmospheric carbon. That's why he's advocating for proforestation policies and actions. His efforts take on more significance given various governments and private-sector organizations' policies and investments in converting cut or downed timber to produce biofuels and heat energy.

A growing need to preserve mature forests and wetlands, and enhance carbon sequestration of farmlands and grasslands

Moomaw is critical of efforts in the Southeastern U.S., where forest canopy loss is greater than anywhere else in the world, that convert forests into wood pellets that are then sold in Europe and elsewhere to produce electricity, for instance, Yale Environment 360 highlights.

Proforestation differs from afforestation, which entails planting new trees. Analyzing research data, Moomaw concluded that we could sequester twice as much carbon from the atmosphere if we managed our forests and grasslands differently. Half the carbon stored in multi-aged forests worldwide is contained in the largest one percent diameter trees, according to one research paper, he pointed out.

"It’s not that we shouldn’t do afforestation [planting new trees] and we shouldn’t do reforestation. We should. But recognize that their contribution will be farther in the future, which is important. But in order to meet our climate goals, we have to have greater sequestration by natural systems now. So that entails protecting the carbon stocks that we already have in forests, or at least a large enough fraction of them that they matter," Moomaw was quoted.

“The most effective thing that we can do is to allow trees that are already planted, that are already growing, to continue growing to reach their full ecological potential, to store carbon, and develop a forest that has its full complement of environmental services. Cutting trees to burn them is not a way to get there.”

Moomaw also emphasized the need to conserve our wetlands, which capture and store the equivalent amount of carbon as do our standing forests, as well as protect and improve the carbon sequestered in agricultural soils and grazing lands. "It’s taken a very long time for people to focus on something besides reducing emissions of carbon dioxide and other greenhouse gases. And to recognize that even though we’re putting almost 11 billion tons of carbon into the atmosphere every year, the increase is only 4.7 billion tons.

"So where is the rest going? It’s going into plants on land and plants in the ocean. And the largest single place that’s removing carbon dioxide [from the atmosphere] on an annual basis is forests," Moomaw said.