World Oceans Day and the Ocean’s Climate Role — Key Actions and Impacts

World Oceans Day spotlight on climate health and the oceans’ role

June 8 marks World Oceans Day, a reminder for governments and society to act to protect the seas. These waters play a crucial part in regulating the climate, yet their current health is under threat from rising temperatures, acidification, and growing human impact. Global warming poses real risks to the oceans, compounding environmental changes driven by human activity and altering life-supporting processes from coastal protection to nutrient cycles.

Climate change brings multiple pressures: rising temperatures, sea level rise, and increasing ocean acidity, as warned by the United Nations. The polar regions are melting at rapid rates, while oceans and ice sheets together help stabilize the planet’s temperature by absorbing a large share of excess heat.

A warming of about 3 degrees Celsius could drive roughly one meter of sea level rise, displacing millions of people from coastal zones and affecting nations around the globe, with Spain highlighted as particularly vulnerable. Even a more moderate warming target, such as 2 degrees Celsius in line with the Paris Agreement, would still lead to significant sea level increases and profound consequences for extensive areas, including Spain.

Too much CO2 increases ocean acidity and harms marine life

The oceans currently absorb roughly 20 to 30 percent of CO2 emitted from burning fossil fuels. While this uptake reduces atmospheric CO2, it reduces the pH level of seawater, intensifying acidification. This shift challenges the survival and growth of fish, shellfish, and other marine organisms, with ripple effects for ecosystems and people who rely on them for food and livelihoods.

The coral environment has suffered extensive damage as a result of warming seas, and reports indicate widespread stress on large fish populations and reef systems. Human activity continues to draw more from the ocean than ecosystems can replenish, underscoring the need for a balanced approach that protects ocean vitality while supporting communities that depend on marine resources.

Experts from around the world call for a rebalanced use of ocean resources—protecting marine life, restoring ecosystems, and investing in resilience so oceans can recover their vitality and continue to support life on Earth. The 2022 campaign for the oceans emphasized collective action and shared responsibility.

Five action areas identified for oceans in the climate fight

The United Nations has outlined five priority action areas designed to help oceans contribute to climate solutions. These focus areas are:

Marine-based renewable energy: expanding offshore wind farms, including floating platforms, and advancing innovative ocean energy technologies such as floating solar systems, wave power, and tidal energy.

Sea transport: accelerating the decarbonization of port operations and the broader fleets that include cruise ships, freighters, and tankers.

Coastal and marine ecosystems: safeguarding blue carbon habitats like mangroves, seagrass beds, and salt marshes that have significant carbon storage capacity.

Fisheries, aquaculture, and dietary shifts: reducing the emission intensity of fishing and farming practices by optimizing wild catch strategies and transitioning to lower-carbon food options.

Carbon storage in the ocean floor: advancing research and removing regulatory and economic barriers to minimize environmental impacts of long-term carbon storage on the seabed.

The full deployment of these ocean-based solutions could account for up to one-fifth of annual greenhouse gas reductions needed to meet a 1.5-degree Celsius target by mid-century. Realizing this potential calls for stronger political will, sustained investment, participation by the private sector, new public financing mechanisms, and clear signals in support of technology deployment and transfer, and scientific guidance.

Ongoing commitment at global and local levels remains essential to turn these strategies into tangible outcomes. The ocean’s health and its ability to contribute to climate stability depend on consistent action, coordinated policy, and responsible stewardship that respects both environmental limits and human needs.

Notes from the field and ongoing monitoring remain crucial as communities, industries, and governments work toward a future where the sea’s vitality is restored and safeguarded for generations to come.

Source notes: United Nations and climate science communities emphasize the interconnectedness of ocean health, climate policy, and sustainable development. The information above reflects consensus findings and current assessments from these bodies, highlighting pathways for action and the stakes involved in protecting the world’s oceans.