Planting trees helps fight climate change—but we need billions more seedlings

Credit: Michael Allen | Flickr (CC BY-NC 2.0)

The U.S. must more than double the production of seedlings to meet reforestation goals, researchers say.

National Geographic

Planting trees has quickly emerged as a seemingly simple way to soak up carbon emissions. Everybody likes it: Environmentalists, politicians, and corporations alike are pushing for a rapid expansion of reforestation efforts to help meet climate goals.

This means growing trees—and lots of them—with the expectation that they’ll capture and store carbon dioxide and help prevent it from warming the world beyond the Paris Agreement target of 3.6 degrees Fahrenheit (2 degrees Celsius) above pre-industrial temperatures.

But according to a new study in the journal Frontier, there aren’t enough tree seedlings currently being grown, at least in the United States, to keep up with those goals. If reforestation efforts are to help tackle climate change, the study finds, tree nurseries across the U.S. will have to increase their production to at least three billion seedlings per year— more than double current levels.

This needs to happen “sooner than later,” said the study’s lead author, Joe Fargione, science director for The Nature Conservancy’s North America Region. “You can’t plant a tree until you grow it. And you can’t grow it in the nursery until you have the seed.”

In order to better understand how to increase national tree production levels, Fargione and over a dozen other researchers surveyed 181 federal, state, and private nurseries and foresters last year, representing at least half of all seedling production in the U.S.

The results, released last month, show that the nation’s nurseries are currently producing 1.3 billion seedlings per year, which are mostly going to replace existing trees harvested by timber companies or lost to wildfires. To expand U.S. forests onto an additional 64 million acres identified by the study as ripe for reforestation—and carbon storage—would take another 1.7 billion seedlings a year. That brings the total needed from nurseries to three billion a year, more than a 130 percent increase.

Ramping up seedling production that much, and making sure they live long enough to trap enough carbon emissions, will cost tens of billions of dollars, according to the study. It will require training specialized seed collectors and investing in new infrastructure, as well as bolstering long-term monitoring to ensure forests survive in the face of pests, disease, drought, and wildfires—threats that are all on the rise because of climate change.

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