Plastic straws

plastic straws don't often end up in the ocean

"Currently, more than 460 million metric tons of new plastic are produced globally each year, and that number is increasing year after year," says Jackie Nuñez, founder of The Last Plastic Straw and Plastic Pollution Coalition's advocacy and engagement manager. "The conversation about single-use plastic and the pollution it causes is now mainstream and global."

The anti-plastic straw movement helped rally public support that eventually turned into large-scale, high-level action. In 2022, the UN Environment Assembly began negotiating a Global Plastics Treaty with 170 countries to address plastic pollution globally and aims to have it in place by the end of 2024.

Despite their relatively small environmental impact when compared to other forms of plastic, plastic straws have become a case study for the impact a piece of single-use plastic can have throughout its life cycle.

Surprisingly, despite being made of fossil fuels, one study from researchers in Thailand suggests that traditional plastic straws made from polypropylene have a smaller carbon footprint than bioplastic (polylactic acid) straws, which are supposed to be biodegradable.

After assessing the greenhouse gas emissions attributable to the raw materials, manufacturing and disposal of the straws, the researchers found polylactic acid straws produced more emissions due to amount of land needed to grow and harvest the natural materials used to make them.

Polylactic acid straws have also recently been found to not be as biodegradable as was first believed.

The amount of greenhouse gases released during the lifecycle of paper straws has been estimated to be anywhere from the same as plastic straws to a quarter of the emissions. One set of life cycle assessments performed by researchers in Brazil in 2020 produced similar results, finding paper straws had a higher relative environmental impact than plastic ones.

Again the land use needed for the raw materials – trees – was the main reason. The study didn't, however, account for their impact on marine life, where researchers admitted plastic straws would likely have the higher impact there since paper straws degrade quickly in water.

It's worth noting that much like plastic straws, paper straws typically can't be recycled (they break down too much when they hit liquid) and an assessment by the UK government also concluded that paper straws emit more greenhouse gases when they rot in landfill compared with plastic.

I initially embraced the anti-plastic straw movement because it felt like a concrete action that protects marine life. While that's true in part, according to Shelie Miller, professor of sustainable systems at the University of Michigan, most straws end up being incinerated or tossed in a landfill.

Once in landfills, plastics degrade slowly, breaking down to become microplastics that can leach out into the wider environment or even produce potentially harmful chemical contamination. But the amount of greenhouse gases produced by plastic straws is relatively low.

"[Avoiding] one car trip totalling 72.4 km (36 km each way) is the [emissions] equivalent of giving up plastic water bottles for four years," says Miller, who did these calculations using the US EPA Waste Reduction Model.

"Most of us would be very concerned if we were throwing away six pounds of plastic every day, but burning one gallon of gas is something we do without thinking about it."

If you want to keep using straws – or need to due to a disability – Nuñez suggests opting for reusable, non-plastic straws. Metal and glass straws are much safer and hold up to wear and tear longer than plastic, but even these have their problems. According to one assessment, a glass straw is responsible for 44 times as many greenhouse gas emissions compared to a plastic one, while stainless steel straws emit 148 times as much.

Bamboo straws are better, but still produce 27 times as much carbon dioxide than plastic. Another study in South Africa found you would need to use a glass straw 23-39 times and a stainless steel straw 37-63 times to neutralise the environmental impact they create when they're made and sold. Fortunately, a well-made reusable straw will work perfectly well for hundreds of reuses.

Another major plus the researchers noted, however, was that reusable straws don't often end up in the ocean.

So, it's far from a simple choice. The scientific evidence is mixed, depending where you look for the harm on the environment. Every expert I spoke with said it's instead better to refuse straws altogether if you are able to. Then you can sit back and enjoy your drink.