Tree Planting Is Booming. Here’s How That Could Help, or Harm, the Planet.

A tree planted for every T-shirt purchased. For every bottle of wine. For every swipe of a credit card. Trees planted by countries to meet global pledges and by companies to bolster their sustainability records.

As the climate crisis deepens, businesses and consumers are joining nonprofit groups and governments in a global tree planting boom. Last year saw billions of trees planted in scores of countries around the world. These efforts can be a triple win, providing livelihoods, absorbing and locking away planet-warming carbon dioxide, and improving the health of ecosystems.

But when done poorly, the projects can worsen the very problems they were meant to solve. Planting the wrong trees in the wrong place can actually reduce biodiversity, speeding extinctions and making ecosystems far less resilient.

Addressing biodiversity loss, already a global crisis akin to climate change, is becoming more and more urgent. Extinction rates are surging. An estimated million species are at risk of disappearing, many within decades. And ecosystem collapse doesn’t just threaten animals and plants; it imperils the food and water supplies that humans rely on.

Amid that worsening crisis, companies and countries are increasingly investing in tree planting that carpets large areas with commercial, nonnative species in the name of fighting climate change. These trees sock away carbon but provide little support to the webs of life that once thrived in those areas.