New bill would require ‘blue carbon’ to offset coastal development

SAN DIEGO — Public developments on the California coast would be required to capture carbon in wetlands or other natural systems under an Assembly bill that calls for projects to add “blue carbon” measures to their mitigation plans. Blue carbon refers to coastal habitat such as wetlands, marshes, kelp forests and eelgrass beds that capture and store carbon in soil, plant matter and the sea floor. AB 2593, authored by Assemblymember Boerner Horvath, D-Encinitas, would require projects on public lands to compensate for greenhouse gas emissions by building or contributing to blue carbon projects.

“It’s a way to develop our coastline, while protecting some of California’s remaining unique important areas,” Boerner Horvath said. “Instead of damaging them, we can double down and reinforce the things that are really valuable — seagrass, flora and fauna.”

If the bill passes, it would add blue carbon mitigation to the suite of factors that the California Coastal Commission considers when it approves coastal permits.

Under California law, any project that affects coastal resources must take measures to avoid or minimize its negative impact. If it can’t avoid that entirely, developers must offset the effects of the project with mitigation measures that replace or restore the resources it will damage. For projects that affect tidal or ocean habitat, that may include planting new eelgrass beds or restoring marshland. For instance, efforts to widen Interstate 5 along the San Diego County coast have been accompanied by improvements to San Elijo Lagoon and other wetlands it crosses. Now such mitigation plans focus on improving habitat for native plants and wildlife, along with building amenities such as trails and bike lanes. Under Boerner Horvath’s bill, blue carbon would become another factor the Coastal Commission would evaluate.