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Oceans and Climate Change

The relationship between oceans and climate change often forms key talking points when discussing environmental sustainability. For example, phrases such as ‘the sea levels are rising’, ‘oceans are getting hotter’ or ‘glaciers are melting’ are constantly perpetuated. It is important to understand how much our oceans mean, and how we can ensure their survival into the future.

How can oceans help tackle climate change?

Oceans cover more than 70% of the Earth’s surface. With this amount of coverage, they play a major role in tackling climate change.

Firstly, oceans are considered an influential heat and carbon sink. This means they can hold more heat or carbon than they emit. When carbon dioxide is stored in the ocean, it doesn’t reach the atmosphere, ultimately lessening the greenhouse effect and reducing global warming. However, for oceans to fulfil their purpose as a carbon sink, it is essential to restore and strengthen habitats. For example, the dense shrubbery and sprawling trees of mangrove forests can be found in shallow oceans, especially along the coastline. However, human activity, such as urbanisation, has endangered their survival.

Mangroves on the ocean's coastline
A mangrove habitat along the coastline. Source: Pexels

Secondly, oceans can also produce renewable energy across the world. Primarily, this is achieved through tidal currents. Because currents move without human assistance, they are a perfect source of energy production. Each country is able to access tidal energy because oceans cover such a large amount of the Earth. In comparison, coal and oil are transported excessively long distances because they’re not as widely available. Oceans also have uninterrupted strong winds, which enables the use of wind energy. Harnessing these sustainable mechanisms makes limiting climate change possible.

Habitat restoration is therefore especially important in tackling climate change. Not only does it to improve the ocean’s ability to store carbon, but ensures that it can be used for renewable energy production.

How can oceans accelerate climate change?

On the other hand, the ocean can accelerate climate change if it is not properly managed. This primarily occurs through the effects of ocean warming. Caused by the greenhouse effect, this process can diminish the prevalence of marine species, lower sea levels and prompt glacier melting.

To put it simply, a glacier melting is comparable to the way ice cube melts in a glass of water. It warms up because everything around it is warm, thus causing it to turn into a liquid. This has a number of global warming consequences, which are further explored in ‘6 Ways to Reduce Our Carbon Footprint’, ‘Global warming: What is it and how do we stop it’, and ‘Is the Paris Agreement working?

Ocean warming also places influence on marine species. These animals have adapted to a particular set of conditions over thousands of years, including how much light they receive, how close to the shoreline they settle and their preferred ocean temperature. Since climate change causes a rapid rises in ocean temperatures, cold water marine species cannot survive in warmer conditions. This is especially damaging to coral reefs and slow-moving marine life, which cannot relocate quickly. The shrinking of The Great Barrier Reef is a perfect example of how marine life is under constant danger.

We see the cyclical nature of ocean degradation and the consequences of climate change within carbon sinks. Without key habitats, such as coral reefs, the ocean cannot store as much carbon. Carbon is therefore released into the atmosphere, thus repeating the greenhouse effect.

What can we do?

It can be hard to change our actions with a problem which looms so large. With that being said, we can be more conscious of the issue at hand by making small lifestyle changes. This can include picking up litter at the beach so it doesn’t harm ocean habitats, volunteering to plant trees that grow our carbon sinks and using renewable transport whenever possible. Taking small steps like this will gradually lead to a planet which is globally sustainable.


  • Jeremy is currently working on completing his Masters in Geographical Information System mapping. He tries to live according to two key values: being a respectful and inclusive person, and attempting to be positive and bring happiness no matter the circumstances.