Why the oceans are key in the fight against climate change

When we talk about climate change , the first things that usually come to mind are carbon emissions, melting ice at the poles, or heat waves. However, there is a silent and powerful ally that plays an essential role in global climate balance: the oceans . These blue giants cover more than 70% of the Earth's surface and are responsible for absorbing much of the heat and CO₂ generated by human activity .

Without the action of the oceans, the effects of global warming would already be much more severe. In this article, we explore how they function, the threats they face, and why protecting them is key to ensuring the future of the planet.

The oceans act as thermal and chemical sponges that absorb vast amounts of energy and greenhouse gases. This makes them one of the main regulators of the climate system .

• Heat absorption : More than 90% of the excess heat generated by climate change has been absorbed by the oceans since the 1970s.
• Carbon capture : The seas store approximately 25-30% of the carbon dioxide (CO₂) we release into the atmosphere each year.
• Energy distribution : Through ocean currents , the ocean transports heat from the equator to the poles, moderating temperatures in many regions.

Thanks to these processes, the planet has not warmed as rapidly as it could have. But this capacity has limits, and there are already signs of saturation and stress in marine ecosystems.

Certain areas of the oceans act as natural carbon sinks , helping to mitigate climate change:

1. Mangroves, seagrass beds and marshes
   • These coastal ecosystems capture up to 10 times more carbon per hectare than terrestrial forests .
   • They also protect coasts from rising sea levels and intense storms.
2. Phytoplankton
   • They are microscopic organisms that live on the surface of the sea and carry out photosynthesis.
   • They produce more than 50% of the planet's oxygen and capture huge amounts of CO₂.
3. Corals
   • Although they are not carbon sinks in themselves, coral reefs sustain marine biodiversity and help maintain ecological balance.
   • They are extremely sensitive to warming and acidification of the water.

Protecting these ecosystems is an effective and low-cost climate strategy , but also a race against time.

The climate crisis also directly affects the oceans, reducing their ability to continue serving us:

• Rising water temperatures : This is altering species migration routes and causing mass coral bleaching.
• Ocean acidification : Absorbed CO₂ is converted into carbonic acid, which harms marine life, especially mollusks and crustaceans.
• Oxygen loss : Warming reduces the solubility of oxygen, causing dead zones where many species cannot survive.
• Rising sea levels : Threatens millions of people living in coastal areas and can trigger climate migration.

These changes affect not only marine life, but also fisheries, food security and the global economy .

Numerous scientists, governments, and organizations are working to protect the oceans and expand their role in the climate fight:

• Marine protected areas : They already cover about 8% of the ocean, with plans to increase to 30% by 2030.
• Regulation of industrial fishing and underwater mining .
• Mangrove and seagrass restoration projects .
• Offshore carbon capture technologies (still in the experimental stage).

You can also contribute:

• Reducing your single-use plastic consumption.
• Avoiding seafood from unsustainable sources.
• Supporting marine protection initiatives.
• Reducing your overall carbon footprint.

Every action counts. By taking care of your consumption, you also take care of the ecosystems that protect you.

The oceans are one of the greatest allies in the fight against climate change , yet they rarely receive the attention they deserve. They are essential for stabilizing the planet's temperature, absorbing emissions, and sustaining life on Earth.

Protecting them is not an option; it's an urgent necessity . If we want a livable future, we must change our relationship with the seas and recognize that without healthy oceans, there is no healthy planet.