What is blue carbon?

Blue carbon refers to the carbon captured and stored by the world’s ocean and coastal ecosystems, such as mangroves, seagrasses, and salt marshes, which can sequester carbon at much higher rates than terrestrial forests. Option (b) is the most tempting distractor but is incorrect because carbon stored in terrestrial ecosystems like forests and soils is specifically termed "green carbon." The core concept being tested is carbon sequestration, highlighting the critical role of marine biodiversity in mitigating climate change by acting as highly efficient carbon sinks.