How does plastic in the ocean affect climate change? 

By: David Moon

Plastics are everywhere. Plastic pollution has increased to where we can find it everywhere, from Mt. Everest to the Mariana Trench and even in our food. The environmental effects of this widespread pollution are becoming more evident every day.

As plastic envelops the Earth, researchers are finding potential hazards it has on our climate. 

How does plastic pollution affect our climate?

The amount of plastic pollution, both in mass and coverage, impacts Earth’s climate in various ways. Microplastics affect our climate because of their different reflectivity and how they interact with the ocean’s biology and chemistry. These climate impacts will only become more extreme as plastic pollution increases.

Reflectivity of Microplastics 

Due to their color variation, microplastics—especially those found in ocean plastic—can alter surfaces’ albedo, which is its reflectivity. For example, darker microplastics absorb more energy, while lighter ones reflect it, leading to localized climate impacts such as heating and cooling. 

This change in albedo is concerning for microplastics in the ocean, atmosphere, and glaciers because it can lead to localized heating or cooling in the ocean and air. Additionally, darker microplastics in glaciers can cause them to absorb more light and melt faster, increasing the sea level. 

Microplastics chemical interaction with ocean water 

Plastic can be found in many forms, from the apparent types like plastic bags and water bottles to the discrete forms of plastic in sunscreen, chewing gum, and clothes. This diversity of use means that many different chemical formulas make plastic. According to a report by PlastChem-Project, there are more than 16,000 plastic chemicals, 25% of which are toxic. 

Additionally, certain microplastics in ocean plastic are very good at absorbing heavy metals, such as lead, cobalt, and copper, and eventually transporting them into the ocean. As these microplastics degrade from sunlight, they leach many chemicals and heavy metals into the ocean, contributing to significant environmental effects. This concoction of toxins leads to ocean acidification, another form of climate change, which disturbs the ocean’s biology and is why reefs are dying. 

Microplastics effect on biological carbon pump    

The marine biological carbon pump is the process by which CO2 moves from the atmosphere to the bottom of the ocean. It is Earth’s strongest natural defense against climate change, sequestering more CO2 than all terrestrial plant life, but it is at risk due to plastic pollution.

The biological carbon pump process starts with phytoplankton (plant plankton) as they absorb CO2 from the atmosphere for photosynthesis. When these phytoplankton die, they sink to the ocean floor, where the carbon is trapped. More frequently, however, the phytoplankton is eaten by other animals, such as zooplankton (animal plankton) and whales, whose feces and eventual carcasses carry the stored carbon to the bottom of the ocean where it is trapped.

Microplastics disturb the biological carbon pump at every step, weakening Earth’s defense against climate change. For example, when exposed to microplastics, photosynthesis in phytoplankton is altered, while zooplankton feeding rates decrease. Additionally, zooplankton will mistake microplastic for food, changing the buoyancy of their feces and making it less likely to be trapped on the ocean floor. 

This change in the biological carbon pump poses multiple risks, disrupting the climate and the aquatic food web. Ocean plastic has severe environmental effects, as microplastics worsen the climate impact by reducing the amount of carbon absorbed, transported, and trapped at the bottom of the ocean while also moving up the food web.

How does plastic affect climate change?

Plastic pollution in the ocean is not the only way plastic affects climate change, as the production and disposition of the material contributes to 3.4% of all greenhouse emissions. Although this may not seem like a lot, it equates to about 1.8 billion metric tonnes of greenhouse gasses, which would look like 5,436 Empire State buildings. This amount of plastic negatively affects both ends of our climate. It adds more greenhouse gasses into the atmosphere while inhibiting the ocean’s natural ability to absorb and trap carbon. In doing so, it also enters the food chain, further disrupting the environment and its ecosystems.  

How does plastic in the ocean affect the environment?

Plastic destroys both the environment and the ecosystems living in them in a variety of ways, such as;  

• Ingestion by wildlife: Full-sized plastic can cause starvation when ingested, while microplastics have already infiltrated most, if not all, of the food chain. Because microplastics become concentrated when moving up the food web, they can affect feeding behaviors and reproductive organs, even in larger animals like humans.
• Habitat destruction: Microplastics contribute to climate change, which causes a higher rate of climate-related disasters. Additionally, they excrete many plastic chemicals, bleaching coral reefs and contaminating soil. 
• Transporting disease and invasives: Microplastics can act as a vector for malicious microorganisms in the air and water, such as fungi, bacteria, viruses, and parasites. Full-sized plastic can carry organisms to an area they are not native to, introducing an invasive species.
• Entanglement: Full-sized plastic can become entangled with marine life and birds, which can cause death due to entrapment or physical injury, mobility issues, and infection when the plastic cuts into flesh.

How is ocean pollution affecting climate change?

Plastic pollution in the ocean can create climate feedback loops that worsen climate change. More specifically, when plastic destroys ecosystems and environments, directly through pollution or indirectly through climate change, it leads to fewer organisms that can participate in carbon sequestration, such as plants, phytoplankton, and the animals that eat them. 

A lower rate of carbon sequestration causes a higher percentage of greenhouse gasses in the atmosphere, allowing for worsening climate change. This cycle repeats itself as climate change furthers its toll on animals and as we increase the amount of plastic that is dumped each year.

Will people have to move because of climate change?

More and more people will have to move away from climate change as rising sea levels, water scarcity, agricultural disruption, and extreme weather events endanger their livelihood. Climate-related disasters have tripled in the last 30 years, displacing 20 million people from their homes a year.  As the dangers of climate change approach previously safe communities, institutions are sharing toolkits on managed retreats that give people the resources to consider if moving away from climate change is the right decision. 

What communities are displaced by climate change?

The dangers of climate change no longer await our future, as entire communities have already been displaced. These vulnerable towns will either have moved away completely or will have to constantly pay for reparations through higher taxes and/or insurance. In both cases, the people within these communities lose close to everything due to climate change. 

Some examples of such communities are:

• Baden-Württemberg and Bavaria, Germany 2024, Flooding
• Maui, Hawaii 2023, Wildfires
• Isle De Jean Charles, Louisiana 2023, Rising sea levels
• El Bosque, Mexico 2024, Storms and Rising Sea Levels
• Somalia, 2020-present, Drought
• Australia, 2019-2020, Wildfires

Take Action

The consequences of dumping plastic into our oceans are starting to reveal themselves, and if we do not act immediately, they will only worsen. Luckily, organizations like Ocean Blue Project are dedicated to cleaning our oceans and protecting marine life. 

You can make a difference by avoiding single-use plastics, volunteering with Ocean Blue Project, hosting your volunteer group, and spreading awareness about the impact of plastic pollution on the climate. Additionally, Ocean Blue Project pledges to clean 5 pounds of plastic pollution for every $1 donated. Together, we can protect our ocean and the magnificent creatures that call it home.

Author Bio: David Moon is a California State University Long Beach graduate with a degree in Marketing. He learned about the beauty of SoCal’s kelp forests when he started spearfishing. He hopes to conserve these majestic ecosystems for future generations to experience.