The role played by trees in reducing CO2 has up until now been virtually ignored
by Tom Evslin
Trees soak up carbon dioxide from the air and turn it into wood, forest litter, and carbon in the soil (the process is called carbon sequestration). Existing trees annually remove 15% of US emissions of CO2 from fossil fuel use. They have the potential to soak up at least twice as much at a lower cost per ton of CO2 removed than new solar panels or wind turbines.
The 2018 report from the UN IPCC (Intergovernmental Panel on Climate Change) estimates that an increase worldwide of one billion hectares (2.47 billion acres) of forestland would keep global warming this century below 1.5 degrees centigrade assuming that emissions of greenhouse gasses (GHGs) don’t increase from current levels. However, the UN assumed that it would not be practical to increase forestland by that amount so didn’t model the effect of many more trees in its many scenarios.
Last July an article in Science calculated that it is actually quite feasible to add the equivalent of .9 billion hectares of forestland to the 2.8 billion hectares we already have globally. Historically, of course, much more of the earth was forested. The careful study allows for existing cropland, human habitation, soil conditions, slopes, and water availability among other factors. The authors point out that the UN report lists reforestation as the cheapest alternative per pound of CO2 removed from the atmosphere.
More trees and better management of existing forest are back on the table as a significant, perhaps the most significant, climate mitigation strategy. Just before the pandemic grabbed our attention, the World Economic Forum announced the Trillion Tree Initiative to support the already existing Trillion Trees Campaign. Today’s announcement is of the US chapter, 1t.org us, which already has pledges to conserve, restore, and grow 855 million trees. The chapter is led by the World Economic Forum and American Forests (of which I’m a board member). Sponsors include American Forest Foundation, Arbor Day Foundation, Bank of America, Mastercard, Microsoft, National Association of State Foresters, National Forest Foundation, Salesforce, and the cities of Detroit and Dallas.
This is all good news. Where’s the rub? Why hasn’t this happened sooner?
Just as the fossil fuel industry is accused, often justly, of disparaging renewables to protect its business, the renewables construction industry is notably hostile to anything which might divert dollars from additional subsidies for solar panels, wind turbines, and electric cars. Just a little while after the original World Economic Forum announcement, the NY Times ran an op-ed “Planting Trees Won’t Save the World” which says: “Focusing on trees as the big solution to climate change is a dangerous diversion. Worse still [emphasis mine], it takes attention away from those responsible for the carbon emissions that are pushing us toward disaster.” In other words, less expensive and less disruptive plans to save the planet are dangerous because they might cause people to resist the price and disruption of a total ban on fossil fuels. We must be panicked into doing what the authors want.
Here in very green Vermont, where the renewable construction industry has a very effective lobby, our state decarbonization plan only recognizes reductions in greenhouse gas emission towards our decarbonization goal. Taking CO2 out of the air with trees doesn’t count even though it is more effective in terms of pounds of greenhouse gasses removed per dollar than subsidizing electric cars for rich people or over-paying for electricity from solar and wind.
A test for who is a “real environmentalist” as opposed to an environmental opportunist will be support or opposition to forests as an environmental solution which should be funded whenever it is the most effective alternative.
As today’s commitments for 1t.org turn into trees, there will be real carbon savings to point to as well as the ancillary benefits of forests: cooler local temperatures because of shade and transpiration, filtering of health-threatening gasses, cleaner water and less flooding, less severe fires because of better forestry practices, forestry jobs, and more land for both wildlife and recreation. You can learn more about or support 1t.org at 1t.org us.