California should end its emissions offset program, researchers say

By Anne C. Mulkern | 05/29/2025 06:20 AM EDT

A new analysis assails a program that lets major emitters pay for projects such as forest preservation instead of cutting their own emissions.

A forest in New Mexico is shown.

New research criticizes a California program that lets polluters avoid cutting their own emissions by paying to preserve forests such as this one in New Mexico. Jae C. Hong/AP

A California program that lets polluters avoid cutting a portion of their own carbon emissions by funding projects such as forest preservation is doing little to address climate change, researchers say in a new analysis.

Two University of California, Berkeley, professors who wrote the May policy brief are urging state lawmakers to replace the program, known as offsets, as they look to extend California’s market-based system to cut carbon emissions.

The cap-and-trade system requires California’s largest carbon emitters to pay the state pollution allowances in some cases for excessive emissions. But regulated emitters can buy up to 4 percent of what they owe carbon credits in one of the state-approved offset programs throughout the U.S. that are supposed to cut greenhouse gas pollution. Each credit is supposed to represent 1 ton of emissions avoided or abated.

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But many projects approved under the state’s offset program do little to fight climate change, said Barbara Haya, director of the Berkeley Carbon Trading Project, which studies the effectiveness of carbon trading programs and offsets. She and Berkeley research fellow Stephan Lezak wrote the program analysis.

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