Dealing with climate change is one of the greatest challenges faced by humanity. From sustainable energy sources to restrictions on industry, people have taken multiple approaches to help preserve our planet. However, each has its own complexities so governments often resort to simple solutions like planting trees. Does it work? While that may have seemed like a great solution, a new study has found that it may not have had the impact we were hoping for.
That’s a massive setback to our efforts. It also goes to show that dealing with climate change is a more complex issue than humanity imagined. In the past several studies have promoted planting trees as an economical, efficient method to deal with climate change, it seems that there’s more to the story. Yes, it is effective, but only if the right trees are planted. While figuring out that is a challenge on its own, another roadblock mankind faces is politics. Before we understand why politics is an issue, we need to understand why planting trees became such a widely touted strategy.
A Low Cost, High Impact Solution
Planting trees has always been seen as a low cost, high impact solution. It has even become a regular feature of political campaigns, like the UK general election in 2019 when the Labour party promised to plant two billion trees by 2040. Even Trump, notorious for his anti-environmental stance has given his approval to the Trillion Trees Campaign. 40 nations have also backed the Bonn Challenge, a movement to restore 350 million hectares of degraded and deforested land by 2030.
The campaign to plant trees is a result of decades of activism by environmentalists and scientists. A 2019 study in the Journal of Science by scientists backs this theory. The study says: “Ecosystems could support an additional 0.9 billion hectares of continuous forest. This would represent a greater than 25% increase in forested area, including more than 200 gigatonnes of additional carbon at maturity. Such a change has the potential to store an equivalent of 25% of the current atmospheric carbon pool.”
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Essentially, the study makes the basic point that the more trees we plant, the less carbon dioxide will be present in the atmosphere. The less CO2, the cooler the earth will remain. The authors themselves, however, note that there are complexities involved. A key issue being deforestation. If we continue with our current rate of deforestation, the research estimated, we would not be able to plant an equal number of trees thereby reducing the global green cover. The study says “we estimate that if we cannot deviate from the current trajectory, the global potential canopy cover may shrink by ~223 million hectares by 2050.”
Another critical challenge is understanding how new forests function. Until now, scientists had a simplistic understanding of the relationship between forests and the amount of CO2 they absorb and believed that all trees could pull CO2 from the air in a fixed ratio. A study found that this was not the case and that carbon capture potential of any forest depended greatly on local conditions. For instance. looking at Northern China, scientists found that in carbon poor soils, adding new trees did lead to an increase in carbon absorption. But where soils were already rich in carbon, adding new trees decreased the rate of absorption.
Financial Incentives Matter
When it comes to planting trees, there’s only so much a government can do. They can create new green spaces and redesign existing public spaces to accommodate more trees, but ultimately private landowners own more land and therefore are critical to increasing the green cover. Most governments provide an incentive for private landowners to increase green areas. These incentives, often financial, are so poorly designed, that it allows landowners to profit from schemes without really helping tackle climate change.
A study published in June in Nature Sustainability looked at Chile as an example of how this plays out. Chile had a national-level program providing subsidies for reforestation from 1974 to 2012. Chile’s Decree Law 701 became a model for many other South American nations. However, analysis of the real-world impacts of the Chilean example found that the scheme didn’t live up to expectations.
“Chile’s experience can help us understand the climate, ecological and economic impacts that might occur when governments pay landowners to establish massive tree plantations,” Robert Heilmayr, an assistant professor at the University of California Santa Barbara and the lead author of the study told Stanford News. Heilmayr’s study found that “a comparison of simulations with and without subsidies indicates that payments for afforestation increased tree cover through the expansion of plantations of exotic species but decreased the area of native forests. Chile’s forest subsidies probably decreased biodiversity without increasing total carbon stored in aboveground biomass.”
Basically, people were planting large plantations of fruit and rubber trees that they could then profit from. Such plantations don’t help fight climate change, since they “have significantly less potential for carbon sequestration, habitat creation and erosion control than natural forests” according to Stanford News. The article goes on to say that natural forests do these things since they are made up of diverse trees that can support a variety of wildlife. So while more trees were getting planted, they really didn’t help the environment in any way.
The Politics of Trees
Politics is another major stumbling block in the fight against climate change. In Chile, lax enforcement and not enough money from the government allowed landowners to get away with plantations, while the government got to promote its scheme as a success. This was a result of two factors – firstly the lack of understanding around the science and secondly the opportunity to bend the law for profit’s sake. If governments don’t invest more in understanding the science and enforcing laws more strictly, such tree planting schemes won’t help in the fight against climate change.
Restoration ecologist Karen Holl, a professor of environmental science at UC Santa Cruz has been attempting to spread the message that tree planting isn’t enough far and wide. Speaking to Science Daily, she said: “We can’t plant our way out of climate change… It is only one piece of the puzzle.” That message is yet to make its way to the US Capitol though. Introduced by Rep. Bruce Westerman, the Trillion Trees Act is currently making its way through the US Congress. The act is trying to push the federal government to plant a trillion trees, with support from private industry in the US. With bipartisan support, it is very likely to be passed into law soon.
It has, however, met with some resistance. In February 2020, a coalition of 95 environmental groups sent an open letter to the chair of the Natural Resources Committee of the House of Representatives Raúl Grijalva. The letter pointed out eight reasons why the legislation was not fit for purpose stating “this legislation presents a false solution for addressing the climate crisis by misallocating resources to focus on industrial logging rather than on urgently needed steep reductions of fossil fuel emissions.”
It seems like the US has not learnt its lesson from Chile, and despite the opposition will continue to push the Trillion Trees Act. Changing our assumptions over tree planting won’t happen overnight, but without adequate political will, the science will get buried. That is something we cannot afford, as time is running out in our fight to save the Earth.