Can planting a trillion trees save our planet?
What Oregonian doesn’t like trees? We certainly love them here at Metro. Thanks to the investments of voters, Metro shows our love by planting native trees and shrubs in our parks and natural spaces – more than 4 million since 1995.
Now, for the first time, we know how many trees there are actually to love on Earth and perhaps how tree planting can help save the planet from climate change. But having the data is only part of solving a much more complex problem.
There are approximately 3,000 billion trees in the world, according to a 2015 study conducted by researchers at Yale University and published in the prestigious scientific journal Nature. While this is a lot, the number has actually dropped by about half since modern human civilization began, meaning that 10,000 years ago there were twice as many trees. Worse yet, we continue to lose 10 billion trees every year.
Where are they all going? Conversion to farms, ranches, towns and losses due to drought (desertification) are among the biggest contributors to tree loss.
A 2019 study of the Swiss Institute for Integrative Biology suggested that planting 1,000 billion trees would significantly reduce the amount of carbon in the atmosphere and significantly help stop global climate change.
So, should we all get busy planting as many trees as possible, ASAP?
Well, yes and no. Among their many amazing qualities, trees absorb carbon dioxide and release oxygen. Planting a lot of them would – eventually – absorb a lot of carbon dioxide from the atmosphere.
While every tree absorbs carbon, forests – with their many intertwined elements – offer many other benefits. They clean our air and water, reduce flooding, and provide habitat for other plants and animals. In cities, trees especially help keep things cool, reducing what is called the Urban heat island effect, where human activities, asphalt and the built environment lead to much higher temperatures than the surrounding rural areas. Surely the planet can use a lot more of whatever trees provide.
Stopping climate change with a trillion trees, however, is more complicated than it looks.
Forests generally have 100 to 200 trees per acre. A trillion trees would require five to 10 billion acres of land, or two to four times the total land area of the United States. Where would all these trees be planted? By who? Who would pay them? Who would take care of them? What species would be planted? Could they be harvested? Who makes these decisions? What else could this money be spent on?
Many experts believe that the best solution to stopping climate change is to keep fossil carbon like oil, coal, natural gas, and ancient forests in the ground in the first place. They fear that the focus on tree planting will distract efforts to reduce carbon emissions. While trees and forests are wonderful for many reasons, a tree grown in Portland for 10 years either stores about the same amount of carbon as 7 gallons of gasoline or reduces a household’s annual electricity use by 1%. .
The United States added 20 million acres of trees – roughly 2 billion individual trees – between 1990 and 2010. But the United States and our region are still contributing to global deforestation and climate change as importer of forest products and the largest user of fossil resources in the world. fuels.
So while restoring habitat by planting the right trees in the right places is always a good thing and can certainly make a difference regionally, if you really want to save the planet, be sure to take the bus. Or carpool on the way to the planting project and turn off the lights before you leave the house.