Satellites detect no real climate benefit from 10 years of California forest carbon offset

Many companies promising “net zero” emissions to protect the climate rely on large tracts of forests and so-called carbon offsets to achieve this goal.

On paper, carbon offsets appear to balance a company’s carbon emissions: the company pays to protect trees, which absorb carbon dioxide from the air. The company can then claim the carbon dioxide absorbed as an offset that reduces its net climate impact.

However, our new satellite analysis reveals what researchers have suspected for years: forest offsets may not do much for the climate.

When we looked at satellite tracking of carbon levels and logging activity in California forests, we found that carbon is not increasing any more at the state’s 37 offset project sites than in other areas, and logging companies are not logging less than before. .

The findings send a pretty grim message about efforts to control climate change, and they add to a growing list of concerns about forest offsets. Studies have already shown that projects are often over-funded at the start and may not last as long as expected. In this case, we find a bigger problem: a lack of real climate benefit over the 10 years of the program so far.

But we also see ways to solve the problem.

How Forest Carbon Offsets Work

Forest carbon offsets work like this: trees take carbon dioxide from the air and use it to build mass, effectively locking carbon into their wood for the life of the tree.

In California, landowners can receive carbon credits for maintaining carbon stocks above a minimum required “baseline” level. Third-party auditors help landowners take inventory by manually measuring a sample of trees. So far, this process has only involved measuring carbon levels relative to baseline and has not taken advantage of the emerging satellite technologies we have explored.

Forest owners can then sell the carbon credits to private companies, with the idea that they have protected trees that would otherwise be cut down. These include large oil and gas companies that use offsets to achieve up to 8% of their state-mandated emissions reductions.

The story continues

Forest offsets and other “natural climate solutions” have received a lot of attention from businesses, governments and nonprofits, including at the United Nations climate conference in November 2022. California has one of the largest carbon offset programs in the world, with tens of millions of dollars. going through offset projects, and is often a model for other countries planning new offset programs.

It is clear that offsets play an important and growing role in climate policy, from the individual to the international level. In our opinion, they must be supported by the best available scientific data.

3 potential problems

Our study used satellite data to track carbon levels, tree harvest rates, and tree species in forest offset projects compared to other similar forests in California.

Satellites provide a more complete record than field reports collected during offset projects. This has allowed us to assess all of California since 1986.

From this overview, we have identified three issues indicating a lack of climate benefits:

1. Carbon is not being added to these projects faster than before the projects started or faster than in uncompensated areas.

2. Many projects are owned and operated by large forestry companies, which manage to meet offset requirements by keeping carbon above the minimum baseline. However, these lands have been heavily harvested and continue to be.

3. In some areas, projects are set up on land with less valuable tree species that are not threatened by logging. For example, at a large logging company in the redwood forests of northwestern California, the offset project includes only 4% redwoods, compared to 25% redwoods on the rest of the company’s property. Instead, the offset project area is overgrown with tanoak, which is not marketable timber and does not need protection from logging.

How California Can Fix Its Offset Program

Our research points to a set of recommendations for California to improve its offset protocols.

One recommendation is to start using satellite data to monitor forests and confirm that they are indeed being managed to protect or store more carbon. For example, it could help foresters create more realistic baselines for comparing offsets. Publicly available satellite data is improving and can help make carbon offsetting more transparent and reliable.

California can also avoid setting up offset projects on already conserved land. We found several projects owned by conservation groups on land that already had low harvest rates.

Additionally, California could improve its offset contract protocols to ensure that landowners cannot opt ​​out of an offset program in the future and cut down those trees. Currently there is a penalty for this, but it might not be high enough. Landowners may be able to start a project, receive a huge profit from the initial credits, cut down the trees in 20-30 years, pay off their credits plus penalties, and come out on top if inflation exceeds the liability. .

Ironically, while intended to mitigate climate change, forest offsets are also vulnerable to it – especially in wildfire-prone California. Research suggests that California grossly underestimates climate risks for forest offset projects in the state.

State protocol requires that only 2% or 4% of carbon credits be set aside in a wildfire insurance pool, even though several projects have been damaged by the recent fires. When wildfires occur, the lost carbon can be taken into account by the insurance pool. However, the basin could soon become depleted as the area burned annually increases in a warming climate. The insurance pool must be large enough to cover worsening droughts, wildfires, and disease and beetle infestations.

Given our findings on the challenges of forest carbon offsetting, focusing on other options, such as investing in solar and electrification projects in low-income urban areas, may provide more cost-effective results. , reliable and fair.

Without improvements to the current system, we could be underestimating our net emissions, contributing to the profits of large emitters and landowners, and distracting attention from real transition solutions to a clean energy economy.

This article is republished from The Conversation, an independent nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Shane Coffield, Nasa and James Randerson, University of California, Irvine. If you found it interesting, you can subscribe to our weekly newsletter.

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Shane Coffield received National Science Foundation Graduate Research Fellowship Program funding for his graduate studies at UC Irvine.

James Randerson receives funding from NASA, the U.S. Department of Energy’s Office of Science, the National Science Foundation, and the State of California Strategic Growth Council.