Composting plays a huge role in the fight against climate change, but how do we inspire people to actually do it?

Dr Niki Harre doesn’t talk about behaviour change when it comes to sustainability. Instead, she talks about cultural transformation, the likes of which we’re seeing play out before our eyes.

This transformation is what earns us looks of approval for getting our takeaway flattie in a KeepCup, and has us juggling stacks of groceries out of the supermarket after forgetting a reusable bag.

This, according to Harre, is us developing cultural habits. A professor of psychology at Auckland University, she has spent her career studying the psychology of sustainability. “People want to do what those around them are doing,” Harre says. “We tend to do things out of sheer mimicry, or because it feels socially appropriate, or it feels like a part of our identity.”

Whether you want to call it a revolution or simply great green marketing, we know that we are capable of change. With that in mind, there’s one unsung habit that desperately needs to join the ranks: composting.

It’s not a new concept, but for where we find ourselves today, it is absolutely critical. In fact, composting, and what we do with our compost, has the potential to reverse climate change. It just needs a better marketing campaign.

According to composting innovator Richard Wallis, there are a couple of key reasons we need to compost. Firstly, to divert ‘waste’ from the landfill. Right now, about half of what Auckland households chuck in the bin is food or garden scraps, and could be composted.

What many people don’t understand is that their broccoli stalks and orange peels don’t magically return to the earth when they’re taken to the landfill. Instead, starved of oxygen, they break down anaerobically to produce methane.

This, as many New Zealanders will be painfully aware of, is a greenhouse gas 25 times more potent than carbon dioxide. In other words, we’re putting carbon into the atmosphere that would otherwise be going back into the ground.

So that’s reason one. The second reason is both complex and astonishingly simple, and is all about what we can be doing with compost. “To put it simply,” Wallis says, “laying compost on the earth allows nature’s natural carbon recycling mechanism to take place.”

After all, he explains, it’s been a closed-loop system for billions of years, before humans evolved, named this organic resource as ‘waste’ and invented trucks to cart it away.

“This gets to the real guts of fighting climate change,” says Wallis, who designs and works with communities to implement sustainable solutions. “When plants photosynthesise, they act as a carbon pump, cycling it out of the atmosphere and into the ground. This is called carbon sequestering, and compost enriches the whole process.”

It doesn’t stop with climate change, though. Wallis explains that the food grown in this carbon-rich soil is nutrient-dense and provides food security, something we need to prioritise.

OK, so we’re starting to grasp how important this is. But what are the solutions and how do we weave them into our society? According to Harre, it’s a matter of working with human psychology to inspire people to participate in a compost culture.

She says this begins by starting conversations around food waste, making it uppermost in people’s minds. “Each individual can do this, starting at their workplace,” Harre says, “From there, it really doesn’t take long for people to get on board.”

Once we begin to see our food scraps as a valuable commodity, the next challenge becomes what to do with them. How do we join the dots to restore nature’s circular economy?  

For those keen to get their hands dirty, The Compost Collective is a great resource and runs composting workshops for beginners. If home composting isn’t an option, initiatives such as Share Waste are popping up, connecting people who have food scraps with their composting neighbours.

Meanwhile, We Compost, an Auckland compost collection company, picks up around 40 tonnes of organic food scraps a week. This is mainly from restaurants and corporates, and gets taken to a large-scale composting facility in Tuakau.

However, Wallis says the most effective solution is in a community setting. “Food scraps, leaves, garden ‘waste’, coffee grinds and compostable packaging is best composted either in community gardens or urban agriculture,” he says.

The inevitable question springs to mind – what about the government? Shouldn’t there be council-led compost collection? Under the current Waste Plan, which prioritises home and community composting, this is the last resort. And according to Wallis, this is for good reason.

A kerbside collection would collect food scraps, anaerobically break them down, and burn the (aforementioned) methane that’s produced. Instead, Wallis says the government needs to deliver on their promised support for community solutions.  As is often the case, there is much more to this story than meets the eye. You can learn more about the current Waste Plan here.

So, back to the community. Wallis is the designer behind New Zealand Box, a rat-proof composting box system that digests community volumes (about 100 households worth) of organic matter.

As the vision of urban agriculture starts to take hold, his boxes are cropping up throughout the country. One example is in the OMG (Organic Market Garden) urban agriculture project on Auckland’s Symonds Street.

At OMG, they grow organic food in the middle of the city, sell it to restaurants, and simply could not do it without food scraps. Among many things, it’s a teaching hub, where anyone can come to learn composting and food growing skills to put towards their own community systems.

With projects like this, Wallis says there is rarely a shortage of volunteers, given how intensely satisfying the work is. “Composting this local resource and using it to grow food is a primal instinct with deep roots,” he says.

“It builds community – people have more contact with each other in a common enterprise, they forge strong bonds, and become more trusting of each other.”

This is what Harre’s latest work (and her book, The Infinite Game) is all about. She says that to participate in the common good, people need to trust that others share our values. These community farms and gardens are a chance for us to get stuck in, side by side, with a common goal (saving our earth) in mind.

One enterprise, For The Better Good, is tackling single-use plastic to drive change for this model of circular economy. They sell water in plant-based, compostable water bottles. More importantly though, they actually collect the bottles using collection bins, and compost them in boxes like Wallis’.  

Founder Jayden Klinac says the answer to climate change lies in decentralised, community composting all over the world. “In Wellington, we’ve got a garden getting built where we’re composting, ” says Klinac. “The compost goes on the garden and the food is donated to a local charity (Wellfed) who teach families how to prepare healthy, affordable meals.”

As Harre says, culture change is a combination of so many things. We need some excellent marketing (read: Instagrammable compost piles), community engagement, and governments providing the funding to entrench the habits as we build them.

Right now, it’s about starting the conversations. By starting where we are, we can help compost make the comeback of the millennium.