A proposal for funding nature-based climate solutions without carbon markets

A recent paper highlights some of the problems with carbon offset projects and suggests an alternative funding mechanism.

Nature-based climate solutions have faced widespread criticism in recent years. Peer reviewed scientists, investigative journalists, and environmental organisations and activists have exposed a series of fundamental problems.

A recent paper published in the journal Nature analyses various strategies for improving nature-based climate solutions. A key proposal is to replace carbon offsets with a “contributions” approach. Corporations could make financial contributions to climate mitigation instead of buying carbon offsets.

It’s obvious. We need to both reduce emissions from burning fossil fuels and protect rainforests. We cannot trade the carbon stored in rainforests against continued emissions from fossil fuels.

Anna Trugman is an associate professor at the University of California, Santa Barbara and one of the authors of the paper. In a press release about the paper she says,

“Forests have potential as nature-based climate solutions, aligned with broader sustainability benefits. Unfortunately, a broad body of literature has revealed widespread problems in forest NbCS projects and protocols that undermine the climate mitigation of forest carbon credits and hamper efforts to reach global net zero.”

The lead author of the paper is William Anderegg, a professor of biology at the University of Utah. “Currently, nature-based climate solutions and forest carbon markets are struggling to deliver effective climate mitigation,” Anderegg tells Anthropocene. “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 paper argues that nature-based climate solutions should do the following:

• Lead to net global cooling;

• Result in additional climate benefits;

• Avoid carbon “leakage”; and

• Store carbon long enough to make a difference.

REDD-Monitor would add a few more things that nature-based climate solutions should not do. These would include avoiding land grabs, avoiding human rights abuses, avoiding fortress conservation, and avoiding evictions.

But let’s look at each of the four points from the Nature paper in turn.

Net global cooling

Planting trees can lead to unintended consequences.Trees established in areas where the earth’s surface reflects sunlight, such as snow, bright soils, or grasslands, can lower the albedo effect — the reflectivity of the earth.

“If you go into 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,” Anderegg says.

Libby Blanchard is a postdoctoral researcher in Anderegg’s Utah Lab. In a press release about the paper she says,

“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 the vast majority of carbon-crediting protocols to date.”

Writing on Bloomberg, journalist Natasha White points out that other researchers have come to similar conclusions:

• In a June 2025 study of satellite data, researchers found that in the US, “the impacts of albedo offset approximately half of the recognized non-soil forest carbon storage benefit”. The researchers write that the findings “may temper expectations for forest establishment as a means of mitigating global climate change”.

• In March 2024, researchers found that in most locations changes in albedo from tree planting “offset or even negate the carbon removal benefits with the latter leading to global warming”.

• In February 2021, researchers found that forest loss in mountain areas caused planetary cooling, but forest loss east of the Mississippi River and in Pacific Coast states tended towards net warming.

Additionality

Carbon projects must result in actions that would not have happened in the absence of the project.

Anderegg says,

“You have to change behavior or change some sort of outcome. 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.”

This has been a problem for REDD and other nature-based climate solutions from the beginning. There is always an incentive to overestimate the danger to the forest and therefore the number of carbon credits that can be generated.

Leakage and permanence

Protecting one area of forest can simply lead to forest destroyers moving to another area, or to another country.

The fourth problem is permanence, or how long the carbon project will keep carbon out of the atmosphere. This is crucial because when fossil fuels are burned, carbon that was permanently locked below ground is released to the biosphere. The carbon then cycles in and out of living things and landscapes for thousands of years.

The researchers argue that carbon projects should always aim to keep the carbon locked away for as long as possible. They suggest for at least a century. But trees are increasingly at risk from drought, storms, insects, wildfire and other climate-related hazards.

“You have to know how big the risks are, and you have to account for those risks in the policies and programs,” Anderegg says. “Otherwise, you're going to lose a lot of that carbon storage as climate change accelerates the risks.”

Anderegg’s lab has also carried out research into “buffer pools” that are supposed to account for these risks. The research found that the buffer pool is too small and not based on science.

A contributions approach

In a paper published in the journal One Earth in June 2024, researchers outlined three principles for a contributions approach:

• Contributions to NbCSs must not take the place of direct emissions reductions;

• Contribution approaches should utilize the best science to design rigorous and effective NbCS interventions; and

• When contributions benefits are quantified, independent scientists and other experts should develop and audit quantification methods.

The authors of the recent Nature paper write that companies could allocate a set amount of money per ton of greenhouse gas emission to contribute to nature-based climate solutions. Or they could commit to contributing a percentage of their profits to nature-based carbon 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.