Can American Forests Save the Planet?

I just saw an incredible chart that showed CO2 in the atmosphere going down and global warming starting to slow and reverse! This is not Donald Trump denial, or some nut proposing we destroy asteroids to save the Earth. Here is the chart; it comes from the reputable Tufts University climate scientist, Dr. Bill Moomaw, in a presentation I saw in Washington after Moomaw and his colleague, Danna Smith, gave the longer version to the American Association for the Advancement of Science (AAAS).

Most environmentalists working to prevent global climate change have been focused on CO2 emissions from the burning of fossil fuels – oil, gas, coal – that power industry, cars, electricity, and more. That’s why we ride bicycles, drive Priuses, use LED lights, and put solar panels on the roof. It’s understandable since most greens in the U.S. actually live in cities and suburbs and fossil fuel emissions make up the majority of the nation’s contribution to greenhouse gases.

But Moomaw and Danna Smith, an environmental attorney and the Executive Director of the North Carolina-based Dogwood Alliance, were talking about forests and how trees could save the planet. Their slide show is based on a new, comprehensive report, The Great American Stand: US Forests & The Climate Emergency, they authored for the Dogwood Alliance. It says that we need to preserve and replenish American forests if we are to have a real shot at slowing global climate change. The task is complicated, they say, because not enough environmentalists, despite being derided as tree huggers, know about the benefits of forests and the danger to them from contemporary logging practices in the United States. If American activists do know and care about forests, it’s often ones like the Amazon rain forest, or problems with palm oil in Asia.

I’ve written about the destruction of forests in North Carolina and the slow reduction of tree cover in growing suburbs in Connections. But, frankly, I have not paid enough attention to broader forest issues. I mainly see a forest when I go hiking or bird watching in one on vacation. So, connecting American forests to preventing global climate catastrophe quickly riveted my attention as I joined in an initial meeting with environmental groups that work on forest policy to start a campaign linking American forests to climate change. Here are the key points.

Forests are known in climate jargon as “carbon sinks.” Through transpiration, trees naturally take in CO2 and give off oxygen. They absorb and store carbon dioxide as they grow. If cut down, they no longer store CO2, and when the trees are burned or rot, they give off that stored CO2. The soil left behind when forests are cut down also gives off more CO2 and the whole devastated area, of course, has less biodiversity, and becomes prone to erosion and flooding.

In the race to reduce global greenhouse gas emissions to prevent catastrophic climate change, the Paris agreement calls for keeping the rise is global average temperature in the next half century to no more than 1.5 degrees Celsius – less, if at all possible. That requires deep cuts in fossil fuel emissions, of course. But, unfortunately, how emissions, forests, and carbon sinks are counted is a problem. All forest sinks are counted pretty equally regardless of their age, biodiversity, and ability to absorb carbon over the long-term. Thus, monoculture, commercial tree plantations and young forests that are “restored” after logging are counted as positive even though they absorb far less carbon and destroy ecosystems and biodiversity. So is production of electricity from biomass, such as burning wood pellets made from forests in the American South, that is then counted toward CO2 reductions in EU countries; it is claimed they have fewer emissions than coal-fired utilities and that the forests back in, say, North Carolina, will be replanted and become carbon sinks again. But, again, a close look at forest accounting methods, forest policy, and the realities of logging on the ground globally and in the United States quickly counters these assertions.

The United States is the world’s largest producer of both “roundwood,” or cut trees, and wood pulp while our production of wood pellets for export is expanding rapidly. The result is both continuing deforestation and the degradation of forests as they become either monoculture tree plantations or stands of younger trees that will take far longer to absorb carbon and reach the levels achieved by old-growth forests. And, yet, American forest and energy policy fails to account for forest degradation and sees biomass as carbon neutral energy. And the United States, which was literally covered in forests from Maine to the Mississippi when Europeans arrived, has precious few forests left now. And very few of them are “old-growth” forests with trees over 100 years old that absorb and store the most carbon.

What Moomaw and Smith argue for persuasively is to protect, preserve, and enhance forests globally, but especially in the United States, where protecting, improving and expanding our forests is not seen as part of the solution for global climate change. So. Here’s how the numbers work.

First, we need to reduce both the annual emissions of greenhouse gases and the total amount of carbon stored in the atmosphere. Just since 2011, concentrations of CO2 in the atmosphere have increased from 390 parts per million (ppm) to over 400 ppm. That means the amount of carbon in the atmosphere that traps infrared energy from returning to space has increased from 828 Billion Metric Tons of Carbon (BMtCs) to 850 BMtCs. On an annual basis, human activity gives off about 7.8 BMtCs from fossil fuel combustion and around 1.1 BMtCs from land use, chiefly deforestation for agriculture. However, a lot of these carbon emissions are absorbed by forests (2.6 BMtCs) and by the ocean (2.3 BMtCs). That means that globally, we humans add about 4.0 BMtCs to the atmosphere each year.

Ending deforestation could reduce annual emissions to about 2.9 BMTcs, while, in addition, ending forest degradation, improving soil use, and expanding forest land could bring this figure down to only about 1 BMtc. Then, according The Great American Stand, reductions in fossil fuel emissions could get us to zero emissions, or even real reductions in carbon, depending on how aggressively fossil fuels are reduced and phased out.

Sounds simple, right? But to alert and convince the American public and policy makers to the benefits of reducing and changing logging practices, end electricity production from wood pellets, and then to restore and expand the few forests we do have will take a major campaign. That’s why the Dogwood Alliance and Defenders of Wildlife called the Rachel Carson Council and over a sozen other organizations together to hear directly from Bill Moomaw and Danna Smith. I was persuaded. But getting Americans to worry about trees, as well as Teslas, won’t be easy.