All about the ocean: carbon sinks, oxygen production, heat storage, plus more

While each part of the global ecosystem plays a vital role in sustaining life on earthfrom soil to rivers to plants and treesthe primary life support for the planet comes from our vast, beautiful, deep, ever-changing, always-providing oceans.

Oceans cover 70 percent of the Earth’s surface and play a vital role in providing resourcesfrom the air we breathe to the food we eat. They regulate the weather we experience and the climate that allows our global population to survive. Oceans are responsible for rainfall, droughts and floods. They provide sources of employment, habitats for marine species, and are the world's largest storer of carbon.

But our oceans are under severe threat, and if human activity continues with business as usual, the delicate balance of our oceans will likely reach a critical tipping point. The changes in our oceans are leading to more extreme weather events, shifting ocean currents, rising sea levels, and melting of glaciers and ice sheets. Problems such as pollution, overfishing, ocean acidification, habitat degradation and heating are threatening the oceanic content and the marine species that live there, bringing dire ripple effects to our global population.

In order to fully comprehend the significant role that oceans play in regulating the planet, let’s explore their vital services as carbon sinks, oxygen producers and heat storers.

Carbon sinks

plastic pollutionPhoto by Naja Bertolt Jensen on UnsplashOne of the main ways oceans maintain the global ecosystem is by acting as carbon sinks. A carbon sink is anything that absorbs more carbon from the atmosphere than it releases, and along with oceans, includes plants, forests and soil.

Human activities are depleting the supply of the planet’s carbon sinks to the point where we are now releasing more carbon into the atmosphere than the environment is naturally able to absorb. These activities include deforestation, burning fossil fuels, livestock operations and one of the biggest threats to the ocean, which is plastic pollution.

Oceans are massive carbon sinks, absorbing about 30 percent of CO2 from the atmosphere. The phytoplankton in the ocean, consisting of microscopic marine algae and bacteria, play a critical role in the global carbon cycle, absorbing almost as much carbon as all the plants and trees on land combined. But negligent human behaviour is filling the ocean with microplastics, which are being consumed by the plankton, and impacting their ability to trap carbon.

As excess carbon dioxide is propelling our planet into a climate crisis, protecting these carbon sinks is of the utmost importance.

Oxygen production

phytoplanktonPhoto by NOAA on UnsplashAlong with absorbing carbon dioxide, the ocean also keeps the atmosphere in check by producing oxygen. Marine plants take carbon dioxide and sugar and transform it into sugars to be used for energy via photosynthesis.

The oceans are responsible for a massive part of the oxygen we breathe. Scientists estimate that 50 to 80 percent of the oxygen in the atmosphere is produced by marine plants (it’s difficult to calculate the exact percentage, as the amounts are always changing).

Although phytoplankton are tiny, they play a huge role in sustaining the planet. In fact, the smallest type of phytoplankton—Prochlorococcus—is known to be the most photosynthetic organism on the planet, producing up to 20 percent of the oxygen in the biosphere. In other words, this tiny organism is to thank for one in every five breaths we take.

As plankton face threats such as plastic pollution, climate change and rising sea temperatures, we must work to save them, and every small step to the earth’s well-being counts.

Heat storage

coral reefPhoto by Shaun Low on UnsplashAnother major way that oceans maintain our planet is by storing heat. As the oceans cover the majority of the globe, they have a very high heat capacity—oceans are the largest solar heat absorber on Earth. They play a critical role in stabilizing the climate system. If it weren’t for oceans, global warming would be occurring at a far more rapid pace than it already is, providing yet another reason why it is important to protect the oceans.

As sunlight reaches the Earth's surface, it is absorbed at the ocean’s surface, and waves, tides and currents move this heat to cooler latitudes and deeper levels. However, as greenhouse gas levels are rising, the planet’s heat isn’t able to escape into space as freely as it used to. Much of the heat is getting trapped in the ocean and is contributing to ocean heat waves and coral bleaching, posing major threats to our planet and the creatures that live here. Scientists predict that if temperatures increase at their current rate, the oceans will be too warm for coral reefs by 2050. A loss of these reefs will risk the lives of all the species that rely on them for food and protection.

The ability to store heat is a very crucial function of oceans, but they are being pushed to their limits and the impact is being felt around the globe as evidenced by rising atmospheric temperatures, melting glaciers and ice sheets, as well as rising sea levels.

Save our oceans

Now that we know more about the critical ways in which oceans protect and maintain the planet, it’s clear how important it is for us to do whatever we can to protect them.

We must lead with sustainability in our everyday lives. This can be done through actions such as decreasing our energy use, pollution output, reducing or eliminating plastic, using renewable resources rather than fossil fuels, and pushing for sustainable practices in industries that affect the ocean, such as fishing and tourism. We must respect and maintain habitats both on land and in the water, and assist in ocean sustainability initiatives such as beach clean-ups and supporting sustainable programs and organizations. It's imperative to use our voices and urge our leaders, businesses, and communities to put sustainability first.

Education, awareness and action are of the utmost importance, and we must do everything we can to save our beautiful blue lifelines.