AboutThe Science Behind the Trillion Tree Campaign
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. The new trees soak up CO2 from the air and turn it into wood, forest litter, and carbon in the soil (collectively called carbon sequestration). However, the scenarios the UN uses in its modeling assume much lower levels of reforestation and sequestration and thus require drastic cuts in emissions to keep warming under control.
Last July an article in Science calculated that it is actually very feasible to add the equivalent of .9 billion hectares of forestland to the 2.8 billion hectares we already have. 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 compared both to other ways of removing CO2 and to strategies for reducing emissions. The new forest would almost absorb all the net “extra” GHG humans have added to the atmosphere since the dawn of the industrial age in 1750. “This places ecosystem restoration as one of the most effective solutions at our disposal to mitigate climate change,” according to the authors.
For a long time people have realized that trees play an important role in climate control. That’s why the outrage at the burning of Amazon forests and why “carbon offsets” have been largely used for planting or saving trees. There have been several successful Billion Tree Campaigns. The UN Report and the Science study show that a major part of the effort to reduce the odds of global warming can and should be reforestation. At this year’s meeting of plutocrats in Davos there was an announcement of the Trillion Tree Initiative to support the Trillion Tree Campaign, which had actually launched in 2011. Trilliontrees.org is a joint venture of Birdlife International, Wildlife Conservation Society (WCS), and World Wide Fund for Nature (WWF).; it provides one way to contribute both to prevent further deforestation and to help reforestation. It looks like 2021 is the takeoff year for the trillion-tree concept.
Who could be against a trillion trees? Even Donald Trump said the US is supporting the initiative both when he came back from Davos and in his State of the Union Address (it was one of the few bipartisan applause lines). But the issue didn’t stay unpolitical very long.
Only a few days after the State of the Union, the NY Times ran an op-ed called “Planting Trees Won’t Save the World”. The byline says “the authors are scientists”. They say “Planting trees would slow down the planet’s warming, but the only thing that will save us and future generations from paying a huge price in dollars, lives and damage to nature is rapid and substantial reductions in carbon emissions from fossil fuels, to net zero by 2050.” The first evidence these scientists produce of this assertion is a tweet from Greta.
They also cite some negative comments in Science but somehow miss the original authors’ very effective replies to these.
They go on to say: “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 have to be panicked into doing what the authors want.
The irony is that a total ban on fossil fuel is unlikely to work quickly enough to avert rising temperatures, according to UN predictions, while reforestation and other plant-based strategies have a very good chance to actually reduce GHG levels in the near future so long as emission levels don’t rise any higher.
Last week the International Energy Agency (IEA), the world’s scorekeeper on energy facts, published a report headlined “Defying expectations of a rise, global carbon dioxide emissions flatlined in 2019”. It has the good news that worldwide emissions have already stopped increasing because of an all-of-the above strategy which includes deployment of renewables, natural gas substitution for coal, and increased nuclear. Developing nations increased their emissions, but this was offset by the emission decrease in developed nations – led by the US.
One year’s flatlining doesn’t mean the problem of increased emission has been solved; but it’s a hell of a good first step. This year, because of the coronavirus and its effect on trade, emissions are highly likely to decline. Meanwhile coal use in the developing world is continuing to decline and both nuclear and renewables are being deployed worldwide (as well as some coal in the developing world).
The stage is set for the Trillion Tree Initiative to help start reducing atmospheric GHG levels.
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