Science has provided more than sufficient evidence to inform a collective and global approach to tackle the continued spread of plastic pollution, according to a new report.

Writing in the journal Science, an international group of experts say the need for worldwide action to tackle all forms of plastic and microplastic debris has never been more pressing.

It is clear that existing national legislation alone is insufficient to address the challenge, they say, and the United Nations’ Plastic Pollution Treaty—which will undergo its fifth round of deliberations in November 2024—presents a “tangible opportunity” for joined-up international action.

However, for such a treaty to be truly effective it needs to commit to an overall reduction in plastic production alongside measures to reduce the emission and release of microplastic particles along the entire plastics life cycle. Failing to do so, the researchers add, could bring “a high risk of irreversible environmental damage”.

The article was written to mark the 20th anniversary of the first ever study, also published in the journal Science, to coin the term microplastics to describe the microscopic fragments of plastics in our ocean.

Both studies were led by Professor Richard Thompson OBE FRS, Head of the International Marine Litter Research Unit at the University of Plymouth, and a co-coordinator of the Scientists Coalition for an Effective Plastics Treaty.

It was co-authored by experts in marine biology, sustainability, environmental psychology, global plastics policy, and risk assessment, from: University of Plymouth, University of Bangor (UK); EA—Earth Action (Switzerland); University of Vienna (Austria); University of Wollongong (Australia); and Wageningen University (Netherlands).

“After 20 years of research, there is clear evidence of harmful effects from microplastic pollution on a global scale.

“That includes physical harm to wildlife, harm to societies and cultures, and a growing evidence base of harm to humans. Added to that is the fact that microplastics are persistent contaminants, and once in the environment they are virtually impossible to remove. There are still unknowns, but during the 20 years since our first study the amount of plastic in our oceans has increased by around 50%, only further emphasizing the pressing need for action,” said Richard Thompson OBE FRS Director of the Marine Institute.

Since the publication of the first study in 2004, an estimated 7,000 research studies have been conducted on microplastics, providing considerable evidence in their sources and impacts as well as potential solutions.

Microplastics have been found on every corner of the planet, in more than 1,300 aquatic and terrestrial species, in the food and drink we consume, and in multiple tissues and organs of the human body.

With emissions of microplastics to the environment estimated to be up to 40 megatonnes per year, a number that could double by 2040, predictions indicate the potential for widescale environmental harm moving into the next century.

“Plastic pollution is completely caused by human actions. That’s why we need research on perceptions of risks and benefits of plastic as well as other drivers of policy support and change, integrating a social science perspective,” said Sabine Pahl, Honorary Professor of Applied Social Psychology.