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Week Four - Get Organics Out of My Bins

Save 171 kilograms CO2e per person per year

· Weekly experiments

My preschooler

- Mummy! Toad's doing another poo in the car! Toad always does poos in the car.



- I wonder where it all ends up?

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If you've spent much time with a small child, you'll know that poo fascinates them. We adults have largely lost this interest, which makes for cleaner office conversation but a dirtier waste stream.

This week's experiment was to get all of the organic waste out of my bins. Where I live, organic waste in bins goes to landfill, where it generates carbon dioxide and equivalent emissions (CO2e) - primarily methane. This accounts for around 35% of our household waste and recycling stream by weight, but it generates a whopping 60% of our CO2e from household waste landfill emissions.

How do I get organics out of my bins?

At the moment, I have two options to reduce my organic waste. I can avoid generating it in the first place, or I can process it at home instead of putting it in my bins.

My weekly bin audits showed we were doing pretty well on food waste. We only generate around 200g per week and most of that is the kind of waste I can't put in my compost or feed to my chickens. We didn't make any changes here.

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Avoid food waste

For most Australians, avoiding food waste is a worthwhile thing to do. The average ACT household generates around 3.5 kilograms of food waste each week, which leads to over 350 kilograms of CO2e from landfill each year. Much of this is edible food that should never have been thrown out in the first place.

I went out to Canberra's Recycling Discovery Hub to chat to Robbie Ladbrook, who works for ACT Government's ACT NOWaste. Robbie agreed that food and garden organic waste were the next big challenge. "The ACT Government is introducing a third bin for garden waste at the moment," she said. "But that won't deal with our food waste. We've announced a Roadmap that will include a kerbside collection system for food and garden organics, but it takes time. We have to select the right processing facility and the right site. Some councils have rushed this and ended up with a contaminated end product that has no market, so it ends up in landfill."

I'm not surprised to hear that this is complicated. My carbon analysis on waste in landfill overlooks a huge amount of complexity. For instance, I've omitted the emissions from the garbage trucks that transport our waste and recycling to the facilities. I've also omitted the benefits of making and using compost at home, which will result in higher carbon storage in the soil and a reduced need to produce and transport compost from elsewhere.

On the flip side, I've overlooked the fact that the ACT landfill is capped and captures most CO2e to use as energy (up to 87% capture according to one source, but that strikes me as an optimistic figure). On the other hand, a home composting system generates less greenhouse gas, but then releases all of it straight into the atmosphere. And that's before you compare different home systems - aerobic, anaerobic and vermicomposting - and then factor in other variables like different feedstocks, temperature and moisture.

I found some data on CO2e generation rates from home composting, but not enough to run a useful comparison. I asked Robbie what the ACT Government says? "We'll examine this as part of the Roadmap," Robbie said. "At the moment, we recommend home composting."

The ACT hasn't officially adopted the Love Food Hate Waste program that's popular elsewhere, but the waste educators are using a similar message. "It's beginning to work," Robbie said. "There's a conscious societal change. Celebrity chefs like Jamie Oliver are showing people how to use all their food in everyday cooking, rather than rushing to the shops to buy one special ingredient and then throwing half of it out."

I asked Robbie what she thought of our current environmental problems. "We have to change the way we do things," she said. "We're not going to recycle our way out of this."

Cut 98% in Two Easy Steps?

I'm nervous about my bold plan to cut my carbon footprint by 75%, but these waste weeks have given me hope. I slashed my CO2e by 98% on the ACT average. I've gone from generating around 300 kilograms to 5 kilograms CO2e per person per year, and I've done it in two easy steps.

1. Better paper recovery. I made sure all my recyclable paper went into the recycling bin. I used better home sorting and I didn't use tissues or paper towel at all.

2. Better organics recovery. I avoided creating food waste by using our food wisely. I composted the scraps or fed these to my chickens. I used our garden waste in the garden.

While the waste weeks have only made a small dent in my overall 22.5 tonne budget, it's a step in the right direction.


Spreadsheet calculations, data sources and references in 'Notes' section, Week Four.