New Zealand could be sending nearly 9000 tonnes of plastic into the environment each year by 2030 – and that doesn't include the containers of waste we're shipping overseas.
That's according to a new analysis that's found enough plastic to fill two Westpac Trust Stadiums could be flowing into the world's oceans, rivers and lakes every day by the end of the decade, if countries fail to seriously rein in plastic pollution.
A new study, led by New Zealand researcher Dr Stephanie Borrelle and published in prestigious journal Science, has called for a "fundamental transformation" of the global plastic economy where products would be re-used rather than wasted.
Borrelle – a Smith postdoctoral fellow at the University of Toronto in Canada – and colleagues developed a model that generated country-level emissions of plastic from 2016 to 2030 under different scenarios.
It outlined the level of effort that all countries, including New Zealand, would have to implement to pull emissions down to a goal of eight million metric tonnes (Mt).
Already, the researchers estimated New Zealand was sending the equivalent of 800 shipping containers full of plastic entering the environment.
"While the Government here is doing a lot in terms of addressing the issue, we estimated that this year New Zealand will emit as much as 4500 tonnes of plastic into the environment, not including the plastic materials that are shipped overseas for processing that end up dumped and being burned," she said.
"The results emphasise that this is a global problem and that more needs to be done to reduce the impacts on freshwater and marine ecosystems."
Borrelle and an expert working group modelled future scenarios to hit the 2030 8 Mt target using existing mitigation strategies: reducing plastic waste, including bans; improving waste management; and recovery from the environment through activities like clean-ups.
But even with parallel efforts in all three solutions, the level of effort needed was enormous.
It meant a reduction of between 25 and 40 per cent in plastic waste across all economies, as well as boosting the level of waste management from 6 per cent to 60 per cent in low income economies.
More dauntingly, it would require the clean-up of about 40 per cent of annual plastic emissions.
Such an effort would require a sixth of the planet's population taking part in Ocean Conservancy's International Coastal Cleanup, or a 90,000 per cent increase on the numbers in last year's programme.
"Even if governments around the world meet their ambitious global commitments, and other countries join those efforts to curb plastic pollution, worldwide annual emissions to rivers, lakes and oceans could be as much as 53 million metric tonnes by the year 2030," added study senior author Chelsea Rochman, an assistant professor at the University of Toronto.
"That's far beyond the 8 million metric tonnes amount that was declared unacceptable in 2015."
Borrelle said the future upshot for New Zealand was just as stark.
"In terms of what it means for Aotearoa, imagine a Westpac Trust Stadium full of plastic entering oceans, rivers, and lakes every day by 2030 - and that's an optimistic scenario. It could be two stadiums if we carry on with piecemeal actions that the world is taking now," she said.
"Globally, we predict plastic accumulation in rivers, lakes and the oceans could be as high as 780 million metric tonnes between 2016 and 2030."
Our supposedly clean and green country has a high per-capita use of plastics.
According to Plastics NZ, each of us consumes approximately 31kg of plastic packaging every single year - yet only recycles 5.58kg.
It's also estimated Kiwi households churn through 1.76 billion plastic containers each year – and too much of it is going to our landfills instead of recycling centres.
A recent survey by the Waste Management Institute of New Zealand found households put nearly 100 million plastic drink and milk bottles in their rubbish bins instead of recycling them – with poor labelling and confusing rules across regions largely to blame.
When measured by weight, nearly 40 per cent of household plastic bottles and containers that could be recycled were going to landfill.
Despite increasing awareness about our plastic woes, households still use more plastic containers than they do metal and glass containers combined.
New Zealand might have signed up to stronger provisions in the international Basel Convention – aimed at reducing the flow of hazardous waste between countries – but our track record has hardly been green.
Thousands of tonnes of plastic are shipped offshore each year. Between January and September last year alone, more than 8000 tonnes went to Indonesia and around 7800 tonnes went to Malaysia.
Much of our plastic waste once went to China, but exporters were forced to search for other markets when the country banned such imports to tackle its own pollution.
New Zealand was embarrassed last year when Indonesia sent back three shipping containers of used, contaminated plastic waste.
According to trade data, plastic export tonnages have fluctuated between 2009 and 2018, with an overall increase from roughly 60,000 to 75,000 tonnes - and an associated increase in value of $79 million.
Over the same time, plastic imports have risen from around 400,000 to 575,000 tonnes in the past 10 years, with an associated increase in value of $845m.
While it's been hard to quantify the precise impact that plastic pollution has had on New Zealand's marine life, studies have offered a glimpse at the impact.
More than 700 species of marine life are known to ingest plastic – and one 2015 study found the plastics we throw away have been mistakenly eaten by around 90 per cent of all sea birds alive today.
Plastics have been found to have the greatest impact on wildlife where they gathered in the Southern Ocean, in a band around the southern edges of Australia, South Africa and South America.
Surprisingly, one of the most threatened areas was the Tasman Sea - its surrounding seas had previously been considered to be relatively free of plastic pollution.
About 10 per cent of all seabirds on the planet breed in this part of the world - and many fed on small prey with gelatinous surfaces which look similar to small pieces of floating plastic.
The result could be agonising, causing gut impaction, weight loss and sometimes death.