The carbon stored in ocean ecosystems, such as mangroves and seagrasses, can help protect from runaway global heating, yet is being largely ignored by policymakers, a new report from the Environmental Justice Foundation (EJF) says. The report is backed by an open letter signed by over 7,000 marine and climate scientists, human rights experts, public figures and others, that was delivered to world leaders on World Mangrove Day, calling on them to make ocean protection a keystone of climate action. The open letter is also backed by 90 NGOs from around the world.

More than half of biological carbon is captured by marine life, yet this “blue carbon” is currently neglected in climate policy, the letter states.

If properly restored and protected, coastal blue carbon ecosystems–such as mangroves, seagrasses, saltmarshes and kelp forests–could sequester up to 200 million tonnes of the CO2 humans currently emit every year.

Undervaluing and degrading blue carbon habitats is also a serious risk, the report and letter warn. The current annual loss of seagrass is estimated to release around 299 million tonnes of carbon every year, and for coastal wetlands that figure rises to 450 million tonnes. Only 7.7 percent of the ocean falls into marine protected areas, and only 1.2 percent is beyond national jurisdiction, meaning that the high seas, which make up roughly 61 percent of the ocean’s surface, are almost completely unprotected.

The letter and report urge national leaders to:

• Include specific, legally binding targets to protect and restore blue carbon environments in their updated Nationally Determined Contribution implementation plans.

• Commit to the 30 x 30 ocean protection plan and designate 30 percent of the ocean as ecologically representative marine protected areas by 2030.

• Agree on an international moratorium on deep-sea mining to protect the deep sea from irreversible, large-scale harm.

The report also highlights the importance of UN Convention on Biological Diversity negotiations, now twice delayed due to the pandemic, which must set binding, measurable biodiversity restoration and conservation targets and leverage technical and financial support for developing nations to meet such targets.

While both the report and letter showcase the golden opportunity blue carbon provides, they also stress that the protection of these habitats must not be used as a substitute for ambitious decarbonization, which is needed across all sectors, in a whole-of-the-economy approach.

Read the full open letter here.

Read the report here.