A new study critiques carbon offsets and lays out a roadmap for improving nature-based climate solutions, emphasizing forest carbon storage, durability, and systemic reform.
Carbon credits once promised corporations a pathway to greener reputations. But a growing body of research is calling those promises into question. A new study published in Nature on July 25, led by the University of Utah’s Wilkes Center for Climate Science & Policy, lays out a data-backed framework for improving nature-based climate solutions (NbCS) — particularly rethinking how forests are used to absorb atmospheric carbon. It’s not an indictment of the forest’s role in mitigating the climate crisis, but a warning: without systemic reform, current practices are falling dangerously short.
“Nature-based climate solutions are human actions that leverage natural processes to either take carbon out of the atmosphere or stop the emissions of carbon to the atmosphere,” said William Anderegg, forest ecologist, biology professor, and the study’s lead author.
“Those are the two main broad categories. There are the avoided emissions, and that’s activities like stopping deforestation. Then there’s the greenhouse gas-removal pathways. That’s things like reforestation where you plant trees, and as those trees grow, they suck up CO2 out of the atmosphere.”
Anderegg’s team, composed of ten researchers from nine universities, focused on forest systems not only because trees act as powerful carbon sinks, but because deforestation continues to emit staggering volumes of carbon. According to the report, deforestation currently releases 1.9 gigatons of carbon dioxide each year — roughly equivalent to the annual emissions of Russia. Yet forests are also responsible for removing approximately 31 percent of anthropogenic carbon emissions from the atmosphere through photosynthesis and carbon sequestration. When functioning optimally, they are the world’s most effective carbon storage system.
But as climate instability grows, so does risk to these systems. Fires, droughts, disease, and increasingly volatile weather events can destroy decades of carbon capture in a single season.
“You have to know how big the risks are, and you have to account for those risks in the policies and programs,” Anderegg said. “Otherwise, basically you’re going to lose a lot of that carbon storage as climate change accelerates the risks.”
One of the study’s central targets is the problematic market of carbon offsets. These are programs that allow corporations to fund nature-based projects—most often forest protection or reforestation to “offset” their own emissions. But the practice is mired in flaws, particularly when it comes to measuring effectiveness.
“There are widespread problems with accounting for their climate impact,” said Libby Blanchard, a postdoctoral researcher in Anderegg’s lab and the study’s second author. “For example, despite the potential for albedo to reduce or even negate the climate mitigation benefits of some forest carbon projects, calculating for the effect of albedo is not considered in any carbon-crediting protocols to date.”
Albedo refers to the way a surface reflects sunlight. Snow and ice, for instance, reflect a great deal of solar radiation, keeping the planet cooler. Dark forests, on the other hand, absorb more sunlight, which can increase local warming. According to the study, in regions dominated by snow cover, planting dense, dark tree canopies could actually result in net warming, even if carbon is sequestered.
“If you go in an ecosystem that is mostly snow covered and you plant really dark conifer trees, that can actually outweigh the carbon storage benefit and heat up the planet,” said Anderegg.
Another flaw in carbon offset models is the lack of true “additionality.” In many cases, companies are credited with preventing deforestation in areas where forests were never actually at risk. This means no real climate benefit occurs, even as corporations count the action toward sustainability goals.
“You have to change behavior or change some sort of outcome,” Anderegg said. “You can’t just take credit for what was going to happen anyway. One great example here is if you pay money to keep a forest from deforestation, but it was never going to be cut down to begin with, then you haven’t done anything for the climate.”
Leakage is also a problem: preserving one forest often just displaces logging or land-use change to another region, particularly in countries with limited enforcement capabilities or competing economic pressures. And then there’s the challenge of permanence. While carbon dioxide molecules from burning fossil fuels can remain in the atmosphere for thousands of years, tree-based carbon storage is vulnerable. Wildfires, invasive insects, and prolonged drought can erase carbon gains overnight.
The current system uses “buffer pools” to hedge against these risks. These are essentially reserves of extra carbon credits meant to cover potential losses. But according to Anderegg’s lab, these buffers lack the rigor to account for the intensifying threats posed by climate change. An upcoming study is expected to propose solutions for strengthening these mechanisms.
Rather than abandoning forest-based solutions altogether, the Wilkes Center study offers a structural overhaul that shifts away from credit-based accounting in favor of a contribution model. Instead of allowing corporations to claim measurable offsets against their own emissions, the model encourages voluntary investments into high-integrity climate projects without overpromising quantifiable benefits.
The proposed roadmap outlines four pillars for effective nature-based climate solutions: measurable global cooling, provable additionality, minimal leakage, and long-term carbon durability. “Actions to halt and reverse deforestation are a critical part of climate stabilization pathways,” the authors write.
It’s not a simple fix, but it may be a more honest one.
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