Coral reefs, among the ocean’s most vibrant and productive ecosystems, support tremendous biodiversity and provide important ecosystem services and other benefits for more than 500 million people around the world. Despite covering less than 1% of the ocean floor, coral reefs are home to up to one-quarter of all marine species and provide food, income, and cultural value to coastal communities across the globe. Reefs generate an estimated US$36 billion in tourism dollars per year, and approximately US$5.7 billion in fisheries value.
Less commonly known is that nearly 200 million people worldwide may benefit from shoreline protections provided by coral reefs. Similar to mangroves, seagrass, and saltmarsh, reefs act as natural barriers, buffering shorelines from the full impacts of storms, waves, and flooding. In fact, healthy coral reefs can reduce wave action by up to 97%, according to a global analysis published in 2014 in Nature Communications—a benefit comparable to that provided by traditional gray infrastructure, such as breakwaters.
In the U.S., coral reefs help communities avoid an estimated US$1.8 billion in flooding and other damage and help protect more than 18,000 people from flooding each year. These benefits are so important that some governments are even insuring reefs, such as Mexico did with the Mesoamerican Reef off of the Yucatan Peninsula, to help pay for restoration efforts after reefs suffer hurricane damage. When this reef was battered by Hurricane Delta in 2020, the insurance payout of US$850,000 helped offset the cost of repairing the reefs, speeding up and improving recovery efforts.
For these reasons, countries increasingly are including actions to protect and restore coral reefs as nature-based solutions in their nationally determined contributions (NDCs) to the Paris Agreement. NDCs are governments’ self-defined goals for how they will meet their obligations under the Paris deal; governments must update their NDCs every five years, and have begun to submit their first updates. As climate impacts worsen, the coastline protection reefs provide almost certainly will become more important.
Coral reefs are also frequently found near carbon-rich coastal wetlands, such as mangrove forests and seagrass beds—known as “blue carbon” ecosystems for their ability to capture and store carbon dioxide. These coastal wetlands, along with saltmarsh, not only provide important benefits for biodiversity, coastal protection, and local economies, but also help mitigate the impacts of climate change by capturing and storing carbon in the underlying soil for millennia. In addition, when found together as an interconnected coastal system, live corals, seagrasses, and mangroves provide stronger defenses from storms than each habitat would on its own. In some places, seagrass beds and corals form a first line of offshore defense by reducing wave impacts and stabilizing shorelines, buffering mangrove forests from more serious impacts and ultimately increasing the resilience of coastal regions.
Scientists, however, have predicted a grim outlook for coral reefs. The planet has lost half of its coral reefs in the past 20 years, and could lose over 90% by 2050. With rising sea surface temperatures, coral bleaching events are now occurring five times more frequently than 40 years ago. Coral reefs are also threatened by rising sea levels, ocean acidification, pollution, overfishing, coastal development, and disease. The loss of these ecosystems will be felt acutely by the most dependent communities, adding environmental justice as another driving reason for coral reef conservation policy action.
To help corals survive, countries must aggressively pursue the Paris Agreement targets of reducing greenhouse gas emissions and limiting global warming to 1.5 degrees Celsius, or at least keeping it below 2 degrees, compared to pre-industrial levels.
The Belize government is among those that recognize how coral reefs can help countries adapt to climate change. As it prepares its updated NDC, Belize is considering how to incorporate conservation targets for coral reefs—and mangrove forests—into that document. Along with protection and restoration actions, the government is planning to develop an early warning system to detect declines in coral health.
All parties to the Paris Agreement with coral reefs in their waters should embrace this opportunity to set ambitious coral conservation goals—along with strong greenhouse gas reduction targets—in their NDCs. By protecting coral reefs and coastal wetlands, nations can strengthen natural safeguards against storms and flooding, bolster livelihoods, and foster more resilient coastal communities—all of which are crucial in the face of a changing climate.
Emily Owen works with The Pew Charitable Trusts’ protecting coastal wetlands and coral reefs project.