Global warming and environmental pollution caused by plastic are inextricably entering a “vicious circle”

Global warming and plastic pollution, often seen as unrelated problems, are inextricably caught in a “vicious circle” where one feeds the other, Swedish researchers report. Nature Communication. A mutually reinforcing relationship increases global warming, material degradation, plastic waste, and the leakage of toxic chemicals into the biosphere.

The plastics we use every day will deteriorate faster due to global warming, and one of the consequences of this will be the emergence of demand for more plastic. Meeting this demand will further increase greenhouse gas emissions, which will raise global temperatures, says Xinfeng Wei, a polymer materials researcher at the Royal KTH Institute of Technology in Stockholm.

“By creating a vicious cycle between climate change and plastic pollution, a self-reinforcing cycle is created,” says Wei.

According to the Organization for Economic Co-operation and Development (OECD), plastics accounted for 3.4 percent of global greenhouse gas emissions in 2019, or about 1.8 billion tonnes, mostly from production and processing from fossil fuels. This amount is expected to more than double by 2060.

feedback loop

The researchers describe a feedback loop that links these emissions to heat, moisture, and the weakening of structural bonds that give polymers a wide range of beneficial properties; This is a term for materials such as plastic and rubber that are made of long chains of large molecules.

“The higher the temperature increase, the worse the properties of the materials become,” says Wei. It says the hardness of commonly used plastics such as polyethylene, polypropylene and polyvinyl chloride decreases by more than 20 percent as temperatures rise from 23°C to 40°C.

This disruption means polymer products for everything from clothing to auto parts to home appliances are being replaced more frequently, resulting in increased production volumes and rates. He said side effects range from the unreliability of food packaging to contamination of waterways and fish habitats due to an increase in microplastics.

Impact on the environment

The report also documented the release of volatile organic compounds (VOCs) in a warming climate, as well as other hazardous compounds including lubricants, flame retardants, plasticizers, antioxidants, dyes, and UV/heat stabilizers. The report stated that heat will accelerate the spread, evaporation and leaching of these substances into the air, soil and water.

Researchers point to the combined effects of increased heat and humidity due to global warming. “A warmer atmosphere increases the evaporation of moisture and can also hold more water vapor,” says Wei.

This is bad news for many materials, but when combined with heat it’s particularly damaging to plastics. “The combined effects of increased temperature and humidity create very harsh conditions for these polymers,” says Wei.

To combat plastic pollution and climate change, Wei and co-authors called for attention and mobilization of all sectors involved in the life cycle of plastic.