By Julian Lee & Alex Longley
Considering the growing frenzy to stop using them, and the trillions that have entered into circulation over the past half-century, it’s startling how little is known about the history of the humble plastic bag.
For at least a decade now, the world has been producing hundreds of billions of the things each year, littering coastlines, poisoning fish and prompting policymakers the world over to try to restrict their usage.
The number of countries with some form of curb in place has at least quadrupled over the past 10 years. But as the restrictions gather pace, it’s becoming increasingly clear that nobody has a precise handle on vital data showing if the measures are working. There isn’t even agreement or consistency as to what to constitutes a single-use plastic bag: governments and agencies often use different thicknesses in their definitions.
“No one can tell you on a global level if we are making progress on the amount of plastic that ends up in the ocean,” says Rob Opsomer, Systemic Initiatives Lead at the Ellen MacArthur Foundation, a charity promoting the reuse and recycling of materials.
The plastic bag’s ascent to ubiquity is in stark contrast to its humble beginnings. Made from a material that was invented by accident in the 1930s, it wasn’t until 1962 that the first patent of what we now think of as a plastic bag emerged. Its rise from there was meteoric, with the patent approved for a company called Celloplast in 1965, before being brought into the mass market by chemical businesses like Mobil.
Still, small-scale data sets suggest restrictions do work. For example, curbs in Wales and Northern Ireland appeared to cut usage in those countries by about 80 percent between 2010 and 2014, according to WRAP, a group that monitored usage for the U.K. government over that period. While it appears success then spread across the U.K., Defra, the government department that took over monitoring, counted bag usage differently to WRAP.
Either way, such studies don’t provide a global picture. Retailers in England covered by a government charge supplied 2.1 billion single-use bags in the year to April 2017, according to Defra. That’s 0.6 percent of the 330 billion single-use plastic bags that the The Ellen MacArthur Foundation reckons are used globally annually. The data for Northern Ireland and Wales account for just 0.03 percent of worldwide consumption.
The European Union has a target of using 90 bags per person by the end of 2019, or 46 billion based on its current population. The European Commission, which previously said better data are needed, estimates that approximately 100 billion were used in 2016.
One way to get a handle on the usage of bags is to monitor the consumption of the type of plastic that’s used to make them. That’s a category of high-density polyethylener—HDPE for short—known as film and sheet. IHS Markit Inc., which compiles figures in its annual Polyethylene World Analysis Report, sees the overall category continuing to expand.
“Under our current view we continue to see year over year global demand growth in the film and sheet category globally,” says Joel Morales Jr, Executive Director of Polyolefins Americas at IHS. That’s because the growth of the middle class in high population countries like India and China will continue to be a boon for plastics demand, he said.
Measures to curb the use of single-use bags are also partly offset by people switching to thicker, more plastic-intensive bags, as highlighted in a 2014 review of a ban imposed by Australia’s Capital Territory. While those are usually designed to be reused and recycled, it highlights the importance of clear data and well-defined objectives in improving the way we consume plastic.
And all the while, bags are a tiny subset of the plastics industry. Sacks and bags made of ethylene represented less than 10 percent of plastics imported into the U.S. in 2016, according to the Plastics Industry Association. The Ellen MacArthur Foundation estimates that plastic bags make up just 3 percent of plastic usage globally. And given how little we know about the number of bags out there, producing data for the remaining 97 percent of plastic consumption is going to be a growing problem as governments try and manage their use.
“One of the elements we need going forward is to have a much better body of evidence, understanding and transparency on what plastic usage is,” Opsomer said. “We need to have that evolving year on year, as we can on climate.”
Featured image: Pixabay
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