What's at stake if we can't regrow our forests

In 1930, botanist Harold Lyon had a dramatic idea for fixing Hawaii's deforested landscape: drop nearly 1,700 pounds of tree seeds from an aircraft flying 2,000 feet above the ground. It was an early experiment in aerial seed dropping, a technique that has since been tried in various forms around the world. In 2022, a parachutist skydived over the Amazon with a refrigerator-sized crate, releasing a hundred million native seeds in mid-air. But restoration ecologist Pedro Brancaleon, from the University of São Paulo, worries that such efforts are little more than stunts. He recalls a quote from journalist H.L. Mencken: "For every complex problem, there may always be a simple, elegant, and wrong answer."

The scale of loss and the limits of quick fixes

Since humans began expanding agriculture roughly 10,000 years ago, we have lost nearly 2 billion hectares of tree cover — an area twice the size of the United States. The instinct to reverse this by simply dropping seeds from the sky is understandable, but Brancaleon argues it misunderstands what forest restoration actually requires. "Restoration is not about just releasing seeds where we want to have trees," he says. "Releasing seeds can be part of a solution, but it's just a minor issue considering all of the other more challenging barriers we have to overcome."

The hierarchical decision-making behind real restoration