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.
There is not enough land on Earth to tackle climate change with trees alone, but if paired with drastic cuts in fossil fuels, trees can be an important natural solution. They absorb carbon dioxide through pores in their leaves and stash it away in their branches and trunks (though trees also release carbon when they burn or rot). That ability to collect CO2 is why forests are often called carbon sinks.
In Central Africa, Total Energies, the French oil and gas giant, has announced plans to plant trees on 40,000 hectares in the Republic of Congo. The project — on the Batéké Plateau, a rolling mosaic of grasses and wooded savanna with patches of denser forests — would sequester more than 10 million tons of carbon dioxide over 20 years, according to the company.
To achieve net zero, companies must remove at least as much carbon from the air as they release. Many, like TotalEnergies, are turning to trees for help with that. On the Batéké Plateau, an acacia species from Australia, intended for selective logging, will cover a large area.
The project, part of a Congolese government program to expand forest cover and increase carbon storage, would create jobs, the company said, and ultimately broaden the ecosystem’s biodiversity as local species are allowed to grow in over decades.
But scientists warn that the plan may be an example of one of the worst kinds of forestation efforts: planting trees where they would not naturally occur. These projects can devastate biodiversity, threaten water supplies and even increase temperatures because, in some cases, trees absorb heat that grasslands — or, in other parts of the world, snow — would have reflected.
The Batéké Plateau is one of the least-studied ecosystems in Africa, according to Paula Nieto Quintano, an environmental scientist who has focused on the region.
Experts acknowledge that forest restoration and carbon sequestration are complex, and that commercial species have a role to play. People need timber, a renewable product with a lower carbon footprint than concrete or steel. They need paper and fuel for cooking.
Planting fast-growing species for harvest can sometimes help preserve surrounding native forests. And, by strategically adding native species, tree farms can help biodiversity by creating wildlife corridors to link disconnected habitat areas.
A challenge is that helping biodiversity doesn’t offer the financial return of carbon storage or timber markets.
Many governments have set standards for reforestation efforts, but they often provide broad leeway. Investors prefer them because they bring better prices, said Enrique Toledo, general manager of Reforesta Perú.
A Guest Editorial