BILL MCKIBBEN
Photo by Nancie Battaglia

3rd in a series

Bill McKibben is an author, educator and environmentalist who resides in Ripton. The founder of 350.org, he is Distinguished Scholar in Environmental Studies at Middlebury College, a fellow of the American Academy of Arts and Sciences, and he has won the Gandhi Peace Prize as well as honorary degrees from 19 colleges and universities.

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It was incandescently beautiful in the forests of the mountain East this past fall. I fear I am, on occasion, a literal tree-hugger, and recently I wrote at some length about the enormous value of growing elms and oaks and sycamores and the rest along city streets where they can shade people as the heat keeps climbing.

So it pains me a bit to say, massive tree-planting campaigns are under assault as a climate tool, and that the assault seems to have some real merit. In mid-September a team published extensive data in the journal Nature on the results of a big tree-planting campaign in India. “We find that tree plantings have not, on average, increased the proportion of forest canopy cover and have modestly shifted forest composition away from the broadleaf varieties valued by local people,” they wrote. “Further cross-sectional analysis, from a household livelihood survey, shows that tree planting supports little direct use by local people. We conclude that decades of expensive tree planting programs in this region have not proved effective.” One member of the team, the aptly named Forrest Fleischman of the University of Minnesota, took to Twitter to expand the idea:

“In the last week I’ve started to receive inquiries from people running tree planting programs wanting my help. I am suggesting that they shut down their programs.”

Given that some of the biggest companies on earth have endorsed tree planting as a solution to their carbon emissions, and that there are several Silicon Valley startups enabling this work, and that it seems intuitively helpful, Fleischman had to make his point forcefully, and he did:

1. Land use change is already a major source of carbon emissions. The best way to think about forests absorbing new carbon is to think about this as offsetting carbon emissions lost from past forest destruction.
2. Relatedly, there isn’t enough space on the planet for natural ecosystems to absorb more than a small share of fossil fuel emissions.
3. Trees planted today will absorb carbon in the future. Your emissions today start heating the planet today.
4. Tree planting projects often fail, so if you plant trees rather than reduce your emissions, you might actually be doing nothing.

In addition, he pointed out, if you’re counting the trees you plant, you’re counting the wrong thing: since the point is to sequester carbon, and since big trees do it best, that’s probably where we should be concentrating.

Meanwhile, it’s at least as important to keep existing forests standing. An important article from the Guardian beats an important drum: It is not a climate solution to cut down trees and burn them to produce electricity. I’ve been trying to make this case since 2016; “biomass” burning is not carbon neutral, no matter what an EU directive or a Congressional mandate might maintain. We have to stop burning stuff on this planet — coal, oil, gas, and also wood on an industrial scale, at a time when we should be going all out towards wind and sun. There’s a ball of burning flame 90 million miles away — that’s all the combustion we need.