Ocean Warming: The Forgotten Impact of Climate Change

By Amy Denton, Assistant Editor of GLOBUS

When we think of climate change, we often just think about greenhouse gases in the atmosphere causing the average global temperature to rise, which of course does happen. However, we rarely consider where most of this heat energy goes. The answer to this would be the ocean. A staggering 93% of excess heat from global warming is stored in oceans, meaning our oceans are valuable in the fight against climate change. However, due to the high heat capacity of water in comparison to air, changes in temperature are not as noticeable and often not talked about. Therefore, we must ask ourselves the following questions: why is ocean warming an issue, what governance is already in place to tackle it, and what can we do to help?

Why is Ocean Warming an Issue?

Despite ocean warming being less noticeable than other forms of climate change, it is still a major environmental issue. Increased ocean temperatures lead to thermal expansion and sea-level rise, which can have detrimental effects on coastal communities and ecosystems. They have also been shown to influence extreme weather events, declining populations of aquatic species, and the destruction of coral reefs. A study conducted in areas of the Pacific Ocean such as Australia found that kelp populations, specifically the Macrocystis pyrifera and E. radiata varieties, have been declining in areas where ocean temperatures are increasing as the environment becomes inhospitable. This is extremely worrying as a decline in species’ populations and biodiversity has detrimental effects on food chains and ecosystems. 

What governance is already in place?

Various international accords and conventions have been made and agreed upon over time. The Paris Agreement was implemented in 2015 to tackle climate change by keeping the global temperature increase to below 2°C compared to pre-industrial levels. The agreement also deals with combating and adapting to various impacts of climate change, such as ocean warming, in a more sustainable way. It does this through a pledge and review system in which each country sets their own targets to reach certain goals. 

In terms of the nationally determined contributions (NDCs) which countries have pledged to achieve, there is in fact quite a strong focus on oceans in the Paris Agreement as opposed to past agreements like the Kyoto Protocol. These pledges include a combination of mitigation and adaptation strategies, such as replanting mangroves, seagrass beds, and other species which absorb carbon dioxide from the atmosphere and implementing coastal buffering.

Despite its focus on the oceans, the Paris Agreement may not necessarily be as successful as one would expect. It is inherently flawed in that countries can take as little or as much action as they would like to, leading to a lack of effort from many. The cost of implementing measures to combat climate change can also put countries off participating fully. Therefore, studies are now showing that keeping temperature rises below an increase of 2°C is unlikely.

What can we do to help?

So, our current methods of international governance for climate change and specifically ocean warming may not be as effective as we once thought. But hope is not lost. There are actions we can all take to help protect our oceans and combat ocean warming, including:

• Reducing our contribution to greenhouse gas emissions. In reducing your greenhouse gas emissions, you will reduce the amount of heat energy produced and absorbed by oceans. This is because the greenhouse gas effect will not be as strong. Instead of driving, try walking, cycling, or taking public transport. When you must use a car, try driving vehicles with less harmful engines, that produce less emissions, or try car sharing if you are going with others. Switching to renewable energy is another way in which we can reduce our greenhouse gas emissions.
• Campaign for the protection of coastal ecosystems. Species such as mangroves, sea-grass beds, and coral can absorb and store carbon, reducing the amount of greenhouse gas emissions in the atmosphere. Therefore, we must ensure coastal ecosystems and marine species are protected.
• Teach others about ocean warming. Ocean warming is often a forgotten impact of climate change, as we often just talk about temperature rises in general. Therefore, by educating others on the issue and making it more widely known, they may be encouraged to act too.

Header image by Jakob Owens at Unsplash