Two major environmental crises have garnered increasing attention in recent years: climate change and the spread of plastic pollution. However, these growing problems are often treated as separate and even competing concerns. 

Now, a first-of-its-kind study published in Science of the Total Environment argues the two problems are intimately connected, and that they should be treated as such by researchers and policymakers. 

“[W]e should be striving to tackle both issues simultaneously because they are fundamentally linked,” study lead author Helen Ford, who is conducting a Ph.D. at Bangor University, tells Treehugger in an email.

Interconnected Crises 

The new study brought together an interdisciplinary team of researchers from eight institutions in the U.S. and the United Kingdom, including the Zoological Society of London (ZSL) and The University of Rhode Island. The study was the first to review the existing literature and determine that plastic pollution and the climate crisis interact to make each other worse, according to ZSL.

The study authors concluded that the two problems are related in three key ways.

  • Plastics Contribute to the Climate Crisis: Plastics are predominately made from fossil fuels, and they also release greenhouse gas emissions throughout their lifecycle, from production to transportation to disposal. The expansion of plastic production alone is expected to emit 56 billion metric tons of carbon dioxide between 2015 and 2050 or 10% to 13% of the remaining carbon budget. Switching to bio-based plastics isn’t necessarily an emission-free solution, since they will require land to grow the plant matter to make the new plastics.
  • The Climate Crisis Spreads Plastic Pollution: Research has shown plastics are already cycling through the water table and the atmosphere just like natural elements such as carbon or nitrogen. The impacts of climate change can further speed that cycling. Polar sea ice, for example, is a major sink for microplastics that will enter marine ecosystems when the ice melts. Extreme weather events linked to climate change can also increase the amount of plastics in the marine environment. After one typhoon in Sanggou Bay, China, for example, the number of microplastics found in both sediment and seawater rose by 40%.
  • Climate Change and Plastic Pollution Harm the Marine Environment: The paper especially focused on how both crises harm vulnerable marine animals and ecosystems. One example are sea turtles. Warmer temperatures are causing their eggs to skew more female than male, and microplastics may further increase the temperatures in nests. Further, turtles may get tangled in larger plastics or eat them by mistake.

“Our paper looks at the interaction of plastic pollution and climate change within marine ecosystems,” Ford says. “These two pressures are both already causing real change to our marine ecosystems globally.”

Vulnerable Ecosystems 

The paper examined many ways in which warming waters and increased plastic pollution threaten both the ocean as a whole and individual ecosystems within it. On a larger scale, new combinations of bacteria form on floating plastic trash, while climate change is altering the abundance and range of a variety of underwater animals. 

“Changing bacterial assemblages could have implications for the planet’s nitrogen and carbon cycles and changes in the abundance and distributions of marine organisms have already had an impact on fisheries,” Ford says.

Both plastic pollution and the climate crisis also put pressure on particular environments. Ford, according to ZSL, focuses her research on the world’s coral reefs. 

“There are no marine ecosystems that are unaffected by these issues,” Ford says, “but one of the most vulnerable ecosystems are coral reefs.”

Right now, the major threat to these ecosystems is coral bleaching, which occurs when marine heat waves force coral to expel the algae that give them color and nutrients. These events are already causing mass coral die-offs and the extinction of local species, and they are expected to happen yearly on many reefs this century. 

Plastic pollution may add to these pressures.

“The extent to which climate change threats to corals might be exacerbated by plastic pollution is currently unknown, yet some studies have found plastic to be detrimental to coral health,” the study authors wrote. 

For example, lab studies have shown that plastic may make it harder for coral eggs to fertilize, while field research indicates that plastic pollution may make corals more susceptible to disease. 

An Integrated Approach 

The relative lack of information about how plastic pollution and the climate crisis might together impact coral reefs is just one example of a research gap highlighted by the paper. 

“Our study found that there are very few scientific studies that test the interaction of climate change and plastic pollution directly,” Ford says.”Those that did have had mixed responses. So, it is important that more research is done in this area to really understand the effects that both issues will have on our marine life.”

Overall, the researchers found a total of 6,327 papers published in the last 10 years that focused on ocean plastics, 45,752 that focused on climate change in the marine environment, but only 208 that looked at the two together. 

Ford thought this disconnect might influence the way the two issues are understood by society at large. Scientists tend to specialize in either plastics or climate change and may be less likely to study both at once. 

“There seems to be a separation in people’s beliefs and values between the two issues and this may be largely down to how the issues are portrayed in the media, but then this may come back to how the science community communicates these issues too,” she said.

Ford and her co-authors called instead for an “integrated approach” to these issues that would portray them and their solutions as connected. 

“While we acknowledge that plastic production is not the major contributor to GHG [greenhouse gas] emissions and impacts are largely different between the two crises, when simplified, the root cause is the same, overconsumption of finite resources,” the study authors wrote. 

They put forward two major solutions to both crises.

  • Creating a circular economy, which means that a product does not end up as waste, but instead is either reused or repurposed. Protecting “blue carbon” habitats like mangroves or seagrass, that can sequester both carbon dioxide and plastics.

“We need to keep going to tackle both” plastic pollution and climate change, Ford tells Treehugger, “as both are ultimately jeopardizing the health of our planet.”