Many individuals and companies eager to reduce their climate impact purchase carbon “offsets,” paying for an equivalent amount of carbon to be removed via projects that protect or restore forests, wetlands, and other natural ecosystems that sequester carbon.
But these schemes haven’t been as effective as hoped, in part because they create an incentive for quantity over quality of nature-based climate solutions, researchers argue in a new study published in the journal Nature.
“Currently, nature-based climate solutions and forest carbon markets are struggling to deliver effective climate mitigation,” says study team member William Anderegg, a forest ecologist at the University of Utah. “Our study provides a roadmap to improve these programs in four critical areas and also proposes a novel funding mechanism that could support projects without carbon offsets.”
The study focuses on forests because of their ability to capture such large volumes of carbon. But forests don’t just store carbon; they can also change patterns of cloud cover, release volatile organic compounds and aerosols, and alter the color of the landscape. All of these changes can have either a warming or a cooling effect. So the first requirement for an effective project is to make sure that it results in net cooling, the researchers say.
Second, in order to truly benefit the climate, projects must keep carbon out of the atmosphere for the long term. Most projects don’t guarantee carbon will be kept out of the atmosphere anywhere near long enough. And disturbances from wildfire, drought, pests, and so on can upend even the best intentions. Anderegg and his collaborators are working on strategies for assessing and managing disturbance risks, and aim to publish their findings in the coming months.
Third, a nature-based carbon sequestration project must result in additionality, meaning climate benefits beyond what would have occurred without it. You can’t sell carbon credits for not cutting down a forest that wasn’t going to be cut down anyway. But it can be difficult to estimate alternative outcomes in a rigorous way.
Finally, projects need to account for “leakage:” It’s no good preventing a forest from being cut down if a different forest just gets cut down instead.
The researchers also propose an alternative to the current system of carbon offsets, suggesting that corporations could instead make financial contributions to climate mitigation. Although this wouldn’t aid them in the quest to say they had achieved net-zero emissions, it could be a more scientifically and legally sound way to reduce their climate impact and avert accusations of greenwashing.
Companies could set aside a certain amount of money per ton of emissions to contribute to nature-based climate solutions (essentially levying a carbon tax on themselves), or commit to contributing a certain percentage of profits to such projects.
“An estimated US$27 billion per year could be generated if just 141 high-profit companies spent $100 per ton they emit, representing a small percentage of their profits,” the researchers write.
A contribution approach would reverse the current incentives in the field and instead create a drive for quality over quantity, with project developers striving to create the most effective, most rigorously documented forest carbon sequestration projects.
“What consistently surprises me is how fast this space is evolving and changing,” says Anderegg. “Innovation is excellent, but it has to be based on the best available science and come with careful policy changes to reflect that science. That’s what’s needed next.”
Source: Anderegg W.R.L. et al. “Towards more effective nature-based climate solutions in global forests.” Nature 2025.
Image: ©Anthropocene Magazine.
