As the extensive public process period closes at the California Air Resources Board, fully developed greenhouse gas offset protocols are expected. The resulting accounting system standards—which are unrelated to cap-and-trade or market mechanisms—are hoped to provide public confidence and carbon-offset buyer certainty. Most offsets supposedly rely on planting more trees to use as a carbon sink for greenhouse gases. However, there are no standards by which to measure the amount of carbon that may be absorbed by new planting. Also, there are disagreements in the scientific world over whether some forests in some climates can even be used as a carbon sink. New science reports that tropical climate forests may, but others may not. There is a need to make forest protocols “user-friendly,” prescriptively detailed, and tailored to California forests, said Jeanne Panek, forestry staff lead at the California Air Resources Board, September 6. She also highlighted the international need for high-quality standardized forestry protocols to make project approvals more efficient. With nearly 20 million tons of carbon sink opportunity in California’s national forests alone, there appears to be obvious climate benefits to standardizing greenhouse gas accounting protocols for the forest sector, based on the management, restoration and conservation of native forests. Laurie Wayburn of Pacific Forest Trust (a leading author for the protocols) emphasizes, “This is an enormous opportunity considering the forest carbon bank potential is especially high in California.” But in actuality, the most transparently accurate benefits of forest carbon offsets are that they foster multiple public benefits, such as clean water, wildlife and fish habitat, biodiversity, and local timber economies. What isn’t clear enough, unfortunately, are (real) GHG emission reductions from forests. Editors’ note: For a more detailed version of the CLEANTECH column, please see our new sister publication: E=MC2 – Energy Meets Climate Challenge. You can find it at www.energymeetsclimate.com.