The Climate Action Reserve (CAR) is a nonprofit offset program headquartered in Los Angeles, California, that establishes protocols for greenhouse gas (GHG) reduction projects, accredits third-party verifiers, and operates a public registry where offsets are issued, transferred, and retired. Each offset it issues is called a Climate Reserve Tonne (CRT), representing one metric ton of CO₂-equivalent reduced or sequestered.
CAR traces its origins to the California Climate Action Registry, created by California state legislation in 2001 to help entities voluntarily measure and report emissions. In 2008 the organization restructured, spinning off the Climate Action Reserve to focus on offset project standards while the reporting arm eventually wound down as mandatory state reporting under AB 32 (the 2006 Global Warming Solutions Act) took over.
CAR is one of four offset project registries (alongside the American Carbon Registry, Verra, and the Gold Standard in some contexts) approved by the California Air Resources Board (CARB) to administer compliance offsets under the state's cap-and-trade program. Several CAR protocols — covering U.S. forests, urban forests, livestock methane, ozone-depleting substances, mine methane capture, and rice cultivation — have served as the basis for CARB's compliance offset protocols. Offsets that meet CARB criteria can be converted from CRTs into ARB Offset Credits (ARBOCs) usable by regulated emitters.
Key principles built into CAR protocols include additionality (reductions would not have occurred without carbon finance), permanence (especially for forest projects, backed by a buffer pool against reversal), measurability, and independent verification. The registry also serves voluntary buyers — corporations, universities, and individuals — seeking credible offsets outside compliance markets.
CAR has faced scrutiny common to the broader offset sector, including debates over forest project baselines and the integrity of livestock and ODS credits. It participates in initiatives such as the Integrity Council for the Voluntary Carbon Market (ICVCM) assessment process aimed at tightening voluntary market standards.
Example
In 2014, dairy farms in Wisconsin and New York used the Climate Action Reserve's Livestock Project Protocol to generate CRTs from methane digesters, some of which were later converted into ARB Offset Credits for use by California compliance entities.
Frequently asked questions
A CRT is the unit issued by the Climate Action Reserve representing one metric ton of CO₂-equivalent that has been reduced, avoided, or sequestered by a verified project under a CAR protocol.
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