Science·What on Earth?

Hate raking leaves? You might be an environmentalist

In this week's issue of our environment newsletter, we look at the history of plastic bottling, a new weapon in the fight against ocean plastic and why not raking your leaves is actually a responsible act.

Also: Collecting ocean plastic just got a little easier

(Sködt McNalty/CBC)

Hello, people! This is our weekly newsletter on all things environmental, where we highlight trends and solutions that are moving us to a more sustainable world. (Sign up here to get it in your inbox every Thursday.)

This week:

Plastic bottles: How we got here

(Joel Saget/AFP/Getty Images)

Last week, Coca-Cola was named the most polluting brand in the world in an audit conducted by Break Free From Plastic, a global movement made up of roughly 1,500 organizations calling for the reduction of single-use plastics. Close followers were Nestle and PepsiCo.

It may not be a total surprise, since Coca-Cola itself disclosed in a recent report that it produced three million tonnes of plastic annually.

Plastic is found in all kinds of things, but one of the most prevalent applications is packaging for drinks, including water.

Not that long ago, all soft drinks were kept in glass bottles. (Milk was, too.) You can still find glass bottles of pop, but they're nowhere near as ubiquitous as plastic ones. How did we end up here?

According to Bart Elmore, associate professor at Ohio State University's department of history, it all started with throwaway beer containers in the early 1900s. After Prohibition in the U.S. was lifted, the market opened up, allowing brewers to ship to more distant locations using disposable steel cans instead of glass bottles.

The single-use container was "a way of breaking into those markets with a different kind of container," Elmore said, and "having this kind of throwaway system" meant saving money on reclaiming bottles and cleaning them in-house.

Eventually, Elmore said, the soft drink industry took notice. Aluminum pop cans took off around the 1960s, but Nathaniel Wyeth, an engineer at the chemical company DuPont, wondered why the soft drink industry wasn't using plastic. He was told carbonated beverages would cause plastic to explode, but he eventually created a new, stronger type of plastic: polyethylene terephthalate (PET), which was patented in 1973.

The soft drink industry loved it because it was much cheaper to ship than glass and didn't run the risk of breaking.

Ironically, Coca-Cola realized the environmental cost of this system. In 1969, the company commissioned a life-cycle analysis comparing the use of glass to plastic in areas such as energy expenditure, water pollution, carbon emissions and more. The original report is no longer available, but the scientists behind it reproduced it for the U.S. Environmental Protection Agency in 1974. Their conclusion: A throwaway plastic bottle would not improve on the environmental impact of a glass bottle that was returned 10 times. 

This seems obvious to us now. Coca-Cola went ahead with the plastic bottles anyway. But studies show only nine per cent of all plastic waste is ever recycled, a disturbing statistic when you consider the amount that Coca-Cola alone produces.  

The good news is Coca-Cola and other soft drink makers have signed on to a partnership with the Ellen MacArthur Foundation, which advocates for a "circular economy," where nothing is wasted.

Working with 400 companies in total, the foundation is looking at a variety of solutions for plastic use. For example, Coca-Cola invested $425 million US in a returnable PET bottle system in Latin America in which consumers pay an indirect deposit (i.e. a fee built into the price) when buying the drink, and upon returning the bottle, get a discount on their next purchase. (The bottle is cleaned and reused.) The program has seen a return rate above 90 per cent

Sarah Wingstrand, New Plastics Economy project manager at the Ellen MacArthur Foundation, said the fight against plastic bottle waste is winnable. 

"We're seeing so many organizations that are working within the plastics space actually aligning behind one common vision, which means that everyone is pulling in the same direction — whereas before, it seemed more scattered."

Nicole Mortillaro

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Old issues of What on Earth? are right here.

The Big Picture: Cleaning up our plastic-ridden waters

Dutch inventor Boyan Slat has been preoccupied with cleaning up the Great Pacific Garbage Patch — the roiling, reportedly Texas-sized mass of discarded plastic in the ocean — for years. Now 25, Slat first conceived the idea of a giant system of plastic removal when he was 18, and he managed to roll out his system earlier this year. This past weekend, Slat introduced an additional measure: the Interceptor, a solar-powered vessel that pulls plastic out of rivers using a sophisticated conveyor belt. (See how it works here.)

(Robin Utrecht/ANP/AFP via Getty Images)

Hot and bothered: Provocative ideas from around the web

Fallen leaves: Just leave them be

(Kieran Doherty/Reuters)

The leaves in the fall can be so pretty — that is until they detach from the branches and land on the ground. Then they're pretty unsightly.

Raking leaves can be drudgery, and if you ask Dan Kraus, senior conservation biologist at the Nature Conservancy of Canada, it's unnecessary. That's because keeping leaves on the ground is quite beneficial to your yard and all the denizens of the animal kingdom that come to visit.

Although some native species, like monarch butterflies, migrate when the weather gets chillier, many stay and hibernate, "and if they don't have those places to hide in the winter, they're not going to do as well," Kraus said in a recent interview with CBC Radio's Ontario Morning.

Fallen leaves provide that habitat.

Piles of leaves offer cover and sustenance for all kinds of insects, Kraus said. At the same time, they benefit birds looking for insects to eat. Leaves also provide nutrients for plants.

That said, leaves may not be welcome just anywhere on your property. They should be removed from eavestroughs and storm drains, lest they contribute to flooding. Kraus said that the density of a pile in your yard can also be a concern, as a "thick mulch of leaves" can affect the growth of grass.

People who live in denser, more urbanized areas may find themselves with trees but little to no grass. In that case, the Nature Conservancy suggests contacting your municipality to see if there are programs to donate your collected leaves for use in compost or communal flowerbeds.

Kraus acknowledged that there is often peer pressure from neighbours to keep a tidy, leaf-free yard for pure esthetic reasons. "If you're worried about that, you don't have to go all-in at once – you can leave a small area of leaves in your garden or just under your trees and see what happens."

But he also said that there is a growing awareness that your yard serves a larger purpose.

"People are seeing their backyard as a bit of an ecosystem and a place where they can welcome some of the native plants and animals that we have."

— Andre Mayer

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Editor: Andre Mayer | Logo design: Sködt McNalty


  • A previous version of this story said the Ellen MacArthur Foundation was working with 43 companies on measures to reduce plastic pollution. It is, in fact, working with 400 companies.
    Nov 01, 2019 11:11 AM ET


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