New study shows plastic waste a greenhouse gas hazard

Otautahi - Plastic pollution threatens marine life in many ways, from entangling fish and seabirds to wreaking havoc on their digestive tracts when they mistake it for food.

Now, a new study has revealed another danger  plastics pose to coastal animals: It can actually heat the beaches they call home.

When plastic waste piles up, it creates an insulation layer, rapidly raising the temperature to a point where it is likely unsuitable for most animals, the University of Tasmania's Institute for Marine and Antarctic Studies says.

If plastic production stays on its current trajectory, by 2030, greenhouse gas emissions from plastic could reach 1.34 billion tonnes a year, equivalent to the emissions produced by 300 new 500MW coal-fired power plants.

The research, published in the Journal of Hazardous Materials, looked at the extent and impact of plastic pollution on the beaches of two remote islands in the Indian Ocean.

Researchers found a lot of plastic on the islands — up to three kilograms per square metre — even on beaches that were uninhabited.  The discovered the plastic was having a measurable impact.

They took daily temperature readings of beach sediment in six locations on the islands and found that the plastic had increased daily maximum temperatures by 2.45Cdeg .

The increase in temperature could have serious impacts on marine life, such as crabs and sea turtles.

The hotter beaches could also harm small animals that live in beach sediment and are an important part of coastal ecosystems, as well as an important food source for migratory birds. Researchers say the problem is only likely to get worse unless something is done to stem the plastic tide.

Global plastic production currently doubling almost every decade and much of the plastic debris that accumulates in our oceans eventually making its way onto beaches around the world.

Researchers are concerned that the scale of plastic production and waste means they could still contribute to climate-changing greenhouse gas emissions over time.

Polyethylene, which is used in plastic bags is the most used and discarded plastic in the world, emitted the largest amounts of the greenhouse gasses.