The ocean stands as humanity’s strongest ally in the fight against climate change. It yields about half of the oxygen we breathe, soaks up a quarter of carbon dioxide emissions, and absorbs the majority of the excess heat produced by those emissions. It is often called the planet’s lungs and its largest carbon sink, a vital buffer against climate disruption.
The United Nations emphasizes protecting the ocean as a cornerstone of stabilizing the climate and reducing global greenhouse gases. It notes that safeguarding marine ecosystems is essential for long-term planetary health.
But ocean health is deteriorating. Rising greenhouse gas emissions are warming and acidifying seawater, triggering profound changes for life both underwater and on land. The UN warns that this reduced capacity to absorb CO2 and shield life poses mounting risks across ecosystems.
Seagrass beds and mangroves, along with their food webs, trap substantial amounts of carbon in the atmosphere and can even outpace forested lands in CO2 storage. Protecting and restoring these habitats is a priceless resource in the climate fight.
Mangroves, for instance, lock away about 1,000 tons of carbon per hectare, stored in both biomass and soil. Beyond climate benefits, these ecosystems help sustain healthy fisheries, improve water quality, and shield coastlines from floods and storms.
value of coral reefs
Coral reefs rank among the world’s most economically and ecologically valuable ecosystems. Although they cover less than 0.1% of the ocean, they support more than 25% of marine biodiversity and contribute to the well-being of hundreds of millions of people through conservation, tourism, medicine, and coastal protection. The economic and social benefits radiate to communities reliant on coastal resources.
Marine protected areas represent a top strategy for preserving ocean health. They now cover about 6.35% of the ocean, nearly ten times more than in 2000, according to UN guidelines. Expanding and strengthening these zones is viewed as essential to resilience in the face of climate change.
Efforts to protect mangroves and coral reefs require broad actions. The UN stresses the importance of enlarging protected zones and improving resilience to climate impacts while continuing to advance conservation and sustainable use of ocean resources.
The ocean also offers renewable energy. Tidal and wind sources, along with other natural processes, provide alternatives to fossil fuels. As noted, these approaches can help curb greenhouse gas emissions and contribute to a cleaner energy mix.
The development of wind power has progressed significantly, shifting from traditional usage to technologies that maximize electricity production. It has the potential to meet a substantial portion of global energy needs and to become a central energy source for the planet.
Ocean energy systems exploit the thermal and kinetic energy of seawater, using waves and currents to generate electricity and heat. While still early in commercialization, their growth could surpass current energy demands in the future.
Transition to zero-emission energies
Nearly all global trade operates through waterways, yet shipping accounts for a portion of greenhouse gas emissions. The UN calls for reducing CO2 emissions from ships to zero by 2050, signaling a shift away from fossil fuels toward zero-emission options such as hydrogen, ammonia, methanol, or wind power.
Ecological sea corridors, or carbon-neutral sea routes, are accelerating decarbonization in maritime transport. Routes already in operation include paths between major ports in North America, Europe, and Asia, demonstrating a practical model for cleaner logistics.
Green shipping, a sustainable blue economy, aims to promote development and well-being through responsible production, trade, and shipping that safeguard ocean health.
More than 680 million people live in low-lying coastal areas, making them particularly vulnerable to floods and storms. The risk of extinction from climate-related events is substantially higher in these regions. The UN calls for measures to anticipate risks, reduce vulnerabilities, and implement solutions, including early warning systems and sustainable natural approaches. A 24-hour notice can dramatically reduce damage, and today a significant portion of the global population remains without access to such systems. The World Meteorological Organization is leading efforts to ensure global coverage within the next five years.