18 Jan 2018

Enviro-myths: When clean and green backfires

9:48 am on 18 January 2018

New Zealanders are more environment conscious than ever as reflected in choices like reuse of plastic bags, composting, and donating old clothes.

However, New Zealand experts say the fight to become a more environmentally sustainable nation is a complex issue and isn't always black and white.

close-up of hands in soil

Photo: 123rf

Composting: Better to buy less

Auckland City Council figures show half of the average Auckland household rubbish bin contains compostable material, 40 percent of which is from food waste.

Composting is one alternative to throwing the waste into landfill, but Professor Hugh Campbell from University of Otago's Centre for Sustainability said it would be much better to buy less food in the first place.

"In New Zealand we have this very comforting habit of composting as much as we can and using it on our veggie garden. In reality it's a very expensive way of fertilizing our veggie patch," he said.

Professor Campbell said there was a huge amount of embodied energy in the whole life cycle of a food product.

He said New Zealanders could take note from countries like the Netherlands, where people often biked home from work and bought ingredients for the evening meal on their way home.

"They tend to buy a lot less surplus food and so they don't end up with a refrigerator quite so clogged at the end of the week and then having to dispose of that," he said.

A market

Photo: 123RF

Farmer's markets: Stay local, save on fuel

Professor Hugh Campbell said research from the United Kingdom had shown people often went out of their way to shop at farmers markets.

"People were tending to drive there in their big four-wheel drives and often in locations that were placed in cute little markets that were in the middle of very congested traffic systems."

He said in those cases it was an energy expense to visit the farmers markets and less fuel efficient than just going to the supermarket.

He said experts were constantly having debates about trading off one area of environmental performance against another.

"For the average consumer who would just love to walk into the shop and see a label demonstrating all those qualities averaged out, that just can't happen and it does make it really challenging."

Savemart in New Lynn where second hand clothes in the blue child cancer clothing bins go to be sorted and sold

A second-hand clothing bin in New Lynn. Photo: RNZ / Brad White

Donating Clothes: Buy long-lasting

While cleaning out the wardrobe and donating to the less fortunate can feel good, Otago University associate professor Lisa McNeill said many of the clothes still went to landfill.

"Many donated clothes come from the fast fashion industry, meaning that they're not designed to be long lasting," she said.

"So even if you're thinking someone else might able to use them, they may be at the end of their usable life after three or four washes or wears," she said.

Dr McNeill said another issue was people also tended to use clothes donation as an excuse to buy more, which was again often at the lower end of the fast fashion industry.

She said the average female consumer who has a moderate interest in fashion acquires up to 29kgs of textile and new clothing purchases per year, meaning they're also disposing of a lot too.

She said waste textiles was currently the second biggest pollutant in the world, and recycling often was not possible.

"Many of the fabrics that are used in using the cheaper polyester-based clothes just can not be recycled.

"Some of these fibres would require the type of treatment that would effectively negate the benefit of recycling the clothing in the first place," she said.

She said unless consumer demand decreased, the world would effectively be overflowing with waste textiles.

Mayors from Auckland, Wellington and Dunedin are pushing for a levy on single use plastic bags.

Plastic bags can be recycled in soft plastics recycling bins available in many supermarkets and stores around the country. Photo: 123RF

Recycling: Keep it clean, check your restrictions

WasteMINZ chief executive Paul Evan said up to 10 percent of the goods in an average recycling bin could not be recycled because of what is known in the industry as contamination.

"The most common example, people will make the assumption that all plastics can be recycled and they'll pop those in," he said.

"A classic example would be plastic bags and most parts of the country you can't put them in curbside recycling, as well as any soft plastic you can scrunch in your hand" he said.

Mr Evans said reducing contamination was incredibly important because the cleaner the material, the more likely to be turned into new product.

"We all recycle because we want to environmentally do the right thing and we want to make sure those materials get to the right place."

He said different councils had different recycling systems, so it was important to check what could be recycled locally.

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Photo: wavebreakmediamicro/123RF

Reusable bags: Only worth it in the very long term

Reusable bags are often considered a more environmentally friendly option than single use plastic bags.

However, a study from the Environment Agency in the United Kingdom shows cotton carrier bags should have a life expectancy of 173 uses to negate the environmental impact it would have.

Even then they scored poorly in terms of the energy used to produce the cotton yarn and the fertilisers used compared to single-use plastic bags.

The woven PP bags often sold in supermarkets would have to be used 14 times to have a lower global warming potential than a plastic bag, however it should have a life expectancy of 104 uses, highlighting the need not to forget them at home.

Despite these options not being as ideal as widely thought, University of Auckland's Associate Dean in Sustainability and Associate Professor in Psychology Dr Nikki Harre said it's much better to take some action than none at all.

She said people are trying to do their best in a system they may not understand and while environmental acts like composting and buying reusable bags may not be the optimal option, it's important people keep doing them.

"What they're doing is creating a mindset, a mindset where people are starting to care about these issues, so when it comes to the really big changes we need like policy changes, people are prepared for them."

She said every step people do with good faith is a step they should take and then naturally people will become more mindful and a conscious consumer.

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