When you look at a photograph of the Earth from space, you may be struck by two things. First, you notice small it is: The planet has only limited resources for we humans to use. Second, you notice how blue it is: Over 70% of the planet’s surface is covered by oceans, and we need those oceans to survive.

Our oceans are critical to life on Earth. They provide the food we eat and the air we breathe. And yet oceans do more than that — they also protect us against climate change. Keeping them healthy is crucial for our future.

But how do we do that? First, by understanding their value.

The fisheries that our oceans support feed three out of seven people around the globe. They provide a critical source of protein and income for some of the world’s most vulnerable people. Oceans also generate more than half of the oxygen we breathe and play a vital role in cleaning our air.

Oceans are beautiful and wild. They provide us with some of the world’s most amazing species — from whale sharks to sea turtles to coral — and marine and coastal tourism is responsible for more than 200 million jobs around the world.


But beyond these benefits, oceans also moderate climate change. Oceans have absorbed 26% of all human-made carbon emissions — the pollution we generate by burning coal for electricity and driving our gasoline-powered cars. From the greenhouse gases that do collect in the atmosphere, 90% of the heat they trap is absorbed by the ocean. Without the ocean, the risks of climate change would be more severe and more immediate.

Oceans also play a crucial role in global circulation. Their precise balances of salt and heat carry warm water north in the Atlantic that keep Europe warm, and currents in the Pacific have historically determined storm paths in relatively predictable ways. On top of that, ocean ecosystems store carbon in mangroves, seagrass beds and salt marshes. These same ecosystems serve as buffers against storm surges and sea-level rise.

In total, nature can provide at least 30% of the solution we need for climate change, but we keep losing our blue nature through overfishing and unsustainable coastal development. We need a worldwide effort to address this loss of nature if we are to have a fighting chance at managing climate change.


So what can we do? We can start by changing our own actions, such as sustainably sourcing the seafood we eat. That means being aware of what you are consuming and where it comes from. There are easy ways to do that. Efforts such as the Monterey Bay Aquarium’s Seafood Watch program provide apps and guides for letting you know if the fish that winds up on your plate has been caught in a sustainable way.

We can also avoid products that pollute these important resources — especially single-use plastics like shopping bags, straws and cups. Plastic pollution can wreak havoc on food chains, and if we do not value oceans by keeping them clean, we are less likely to protect them in other ways.

Beyond our own actions, we can get involved in community efforts. My organization, Conservation International, works to protect the most important parts of oceans and coasts around the world. For example, in Brazil, we are working to protect coral reefs that support community fisheries, and in Costa Rica, we are preserving mangroves that help to prevent flooding from storm surges and sea-level rise.


Here in the United States, conservationists are working to protect similar areas for the future. In Florida, advocates are working with the government to restore freshwater flows in the Everglades to prevent rising seas from intruding on the Biscayne Aquifer, the source of all of South Florida’s drinking water. In California, community leaders are trying to stop and even reverse the century-long and ongoing destruction of the San Francisco Bay’s wetlands, which has released 1 billion tons of carbon dioxide into the atmosphere.

Similar efforts are likely under way in your community. Learning about what is happening is the first step to doing something about it.

The ocean provides us with so much. If we want it to keep providing into the future, we need to protect it. This World Oceans Day, find out more about how you can take action to protect the ocean — and protect your community.


Dr. Sebastian Troëng leads Conservation International’s Americas Field Division

Dr. Sebastian Troëng leads Conservation International’s Americas Field Division, with management over the organization’s marine and terrestrial conservation programs and investments in North, Central and South America.