A Massive Plan to Expand Forests—and Save the World

Forests are some of the most incredible places on Earth—teeming with life, filtering our drinking water, and providing us myriad outdoor recreation opportunities. Trees are also the most effective means to capture and store carbon, making them our frontline defense against climate change. For the first time ever, landmark research published this week quantifies how global forest restoration could help us address the climate crisis.

The conclusions are astounding: The restoration of Earth’s forests could capture two-thirds of man-made carbon emissions. The researchers call for a global reforestation action plan to capture this potential.

There’s no substitute for immediate and dramatic greenhouse gas emissions cuts—the kinds that can only be achieved via massive reductions in the use of coal, oil and gas and its rapid replacement with low-carbon options, such as energy efficiency, solar, wind and batteries. But what this new research makes clear is that we cede a mighty tool in the fight for our and our children's lives if we don’t act to conserve, restore and expand forests and other natural ecosystems that sequester and store carbon—everywhere.

Here’s a map of what all that potential reforestation would look like, on top of forests currently standing:

Policies and programs to support this effort must be the priority of all governments around the world. Policies and programs that work against these goals, such as misguided subsidy schemes that incentivize the conversion of industrial-scale power plants to run on wood, must be phased out as soon as possible.

According to the new study, more than half the potential to restore continuous tree cover is in just six countries, the top three being Russia, the U.S., and Canada. Sadly, all three are countries where forests are under major threat, including as harvesting grounds for the so-called biomass industry.

Here in the U.S., the forests of the Southeast—some of the most precious and biologically diverse in the world – are ground zero for the wood pellet industry. Year after year, companies like Enviva, the world’s largest wood pellet manufacturer, source trees from mature hardwood forests. These trees are ground up into wood pellets, loaded onto ships and exported around the world as fuel for power plants.

The top markets for this dirty energy are the UK and other member states of the European Union, where companies Drax Power and Ørsted in Denmark receive lucrative subsidies to burn so-called biomass. These energy giants get to ignore all the carbon spewing from their smokestacks and policymakers get to claim emissions reductions when in fact they’re making climate change worse.

Burning forest biomass for energy emits large amounts of CO₂, which persists in the atmosphere for decades or longer, even if logged trees are immediately replaced with saplings. (And there’s no requirement that the mature trees be replaced with saplings at all.) The large new demand for wood created by support for biomass energy also results in more intensive and extensive logging of forests, thus depleting the very ecosystems on which we depend for sequestering and storing carbon. In other words, the biomass industry takes us in exactly the wrong direction on climate change.

Last year, the Intergovernmental Panel on Climate Change (IPCC) told us that limiting global temperature rise to 1.5°C requires cutting global greenhouse gas emissions in half by 2030 and reaching net zero emissions worldwide by 2050. According to the IPCC, every one-half degree difference above and beyond 1.5°C represents disproportionate additional climate-related suffering, meaning that no effort should be spared to meet this goal.

The IPCC report highlights the risks of overshooting the 1.5°C temperature target, which would necessitate reliance on costly and unproven technologies, such as bioenergy with carbon capture and storage (BECCS). BECCS is assumed to help reduce emissions by creating “carbon-negative” power stations, thus allowing a slower transition away from fossil fuels. But there is no scientific basis for assuming that BECCS can deliver negative emissions after full emissions accounting for biomass in the power sector. Additionally, there is significant scientific basis to believe that large-scale biomass harvesting for BECCS—which would create enormous new demand for forest biomass and further imperil forests around the world—would come at an untenable ecological cost.

This new research on the massive climate mitigation potential of a global reforestation agenda places in stark relief the choice between a future in which we prioritize maximizing carbon storage by forests vs. one where forests are burned for energy. Critically, as described in this excellent post, there is one IPCC scenario that envisions low or no overshoot of climate targets scenario and does not count on biomass electricity generation as renewable energy; in fact, the scenario envisions a decrease in the use of bioenergy and no reliance on BECCS. (Or, as my colleague wrote: Trees! The IPCC Should be Loving Those Trees.)

As scientists turn towards helping us imagine and understand the pathways to such a future, their research breakthroughs must be met with bold policy agendas to make their projections real. That starts by understanding that reliance on forest biomass is incompatible with the aim of phasing out carbon emissions. Policies that promote the use of forest biomass as fuel must be scrapped immediately and biomass subsidies redirected to genuine zero-emission energy technologies. In parallel, bold conservation agendas to keep existing natural forests intact and dramatically expand forested lands must be a priority of all governments seeking to address the climate emergency. The time to act—and plant trees—is now.