Plastic food packaging decaying in parks, on beaches and in the sea have been linked to climate change in eye-opening new research.

Scientists have claimed that plastic food packaging emit the greenhouse gases methane and ethylene when they break down.

The issue has never been factored in to climate change analysis in the past, meaning its potentially dangerous effects could arrive sooner than predicted.

Plastic pollution littering the beach at Kamilo Point on Hawaii’s Big Island (Picture: SWNS)

Polyethylene – the substance used in shopping bags – was found to be the most prolific emitter of both gases.


And production of plastics is set to double over the next 20 years.

Hazmat suited officials detain BA cabin crew after positive test but pilots free to go

Study senior author Professor David Karl, of the University of Hawaii at Manoa School of Ocean and Earth Science and Technology, said: ‘Plastic represents a source of climate-relevant trace gases that is expected to increase as more plastic is produced and accumulated in the environment.



‘This source is not yet budgeted for when assessing global methane and ethylene cycles – and may be significant.’

The team behind the discovery described what they found as ‘unexpected’.

Dr. Sarah-Jeanne Royer said plastic could accelerate the effects of global warming (Picture: SWNS)

They found that plastic bags produced the greenhouse gases when exposed to sunlight – but once initiated, the emissions continued, even in the dark.

Lead author Dr Sarah-Jeanne Royer, of the Centre for Microbial Oceanography at Hawaii University, said: ‘We attribute the increased emission of greenhouse gases with time from the virgin pellets to photo-degradation of the plastic, as well as the formation of a surface layer marked with fractures, micro-cracks and pits.

Hero rat gets gold medal for 'livesaving bravery' clearing landmines

‘With time, these defects increase the surface area available for further photo-chemical degradation and therefore contribute to an acceleration of the rate of gas production.’

Greenhouse gases directly influence climate change, affecting sea level and global temperatures along with ecosystem health on land and in the ocean.

They also trigger storms which increase flooding, drought and erosion.

Got a story for Metro.co.uk? If you have a story for our news team, email us at webnews@metro.co.uk. You can also follow us on Facebook and Twitter.