Decomposing organic waste, like food and green waste are key contributors to greenhouse gas emissions emanating from landfills.
(Listen to the full interview below:)
Locally in Whāingaroa we have a huge opportunity to contribute to reducing emissions simply by supporting the food waste collection service and keeping organic waste out of landfill.
Waikato District Council Senior Advisor on Climate Action, Rachael Goddard says that we have over 900 ‘legal landfills’ in Aotearoa which is “high for a small country,” with an estimated 10,000 contaminated illegal sites on top of the legal landfills.
“Landfills are created by digging a very large hole in the ground and in the past, these holes were never lined, or controlled, you just chucked everything in there.”
Even modern landfills that are lined with plastic and clay can be breached by leachate, a toxic cocktail of chemicals that are produced as the contents break down (think of nappies, electronic good, whiteware, paint, chemicals, rubber, wood, food, pretty much everything we consume and throw away). Leachate can end up in streams, estuaries and rivers, and the heavy metals can be consumed by us.
A study in Auckland years ago showed leachate in an estuary causing lesions on fish and peoples wounds being infected from the water.
Rachael explains that when organic waste like food, cardboard, paper and green waste are placed in landfills, these are the first items to start decomposing. The decomposition process is carried out by anaerobic bacteria (without oxygen) which produce both methane and carbon dioxide which are greenhouse gasses that contribute hugely to climate change.
“Methane has much more warming potential than carbon dioxide. It’s about 86 times stronger over a period of 20 years, and about 25 times stronger over 100 years."
“It’s really essential that we get food waste out of the blue bags,” says Rachael. "Why would you pay to throw that away?"
Aotearoa is currently in the top 10 waste producers in the world which is "embarrassing."
Over the past four years that the food waste collection service has been running in Whāingaroa, Xtreme Zero Waste have diverted 614 tonnes of food waste from landfill which is about 153 tonnes a year.
By diverting 153 tonnes of food waste away from landfill you can reduce landfill greenhouse emissions by roughly 50% per year, which is about 76 tonnes of greenhouse gas emissions.
In terms of volume, an average NZ car emits about 2 tonnes of Co2e every year. So the annual impact of the food waste collection service could be the equivalent of taking about 38 cars off the road.
Looking at the waste audits conducted in Raglan, Xtreme Zero waste found that over 35% of blue bags comprise food waste. In some other parts of the country, food waste can account for up to 50% of the contents of a rubbish bags.
Rachael says that we have a huge opportunity to make strides in ensuring that we keep organic waste away from our landfills because things like food and green waste emit the largest amount of greenhouse gasses when decomposing.
Looking at how much impact food waste can have on our environment and climate, it's really important that we keep the food waste collection service going - even if you don’t use the service - so that we can continue to lower our emissions to mitigate the effects of climate change.
Climate Change Action
In the past 50 years, the world has experienced a five fold increase in natural disasters like flooding, wildfires and storms. Only last week we saw parts of the country impacted by severe flooding with some in Tairāwhiti describing the weather event as the worst since Cyclone Bola in 1988.
“We are experiencing the effects of climate change now, with extreme weather, flooding and drought so it’s more tangible.”
Rachael has spent around 30 years working in the sustainability sector as an environmental scientist with special interests around landfills and the social behaviours we have in relation to waste.
Prior to her new role at Waikato District Council, which she landed earlier this year, Rachael was the Sustainability and Environmental Manager at the University of Waikato for over 9 years.
“Changes are happening faster than anticipated,” says Rachael referring to climate change modelling which scientists use to anticipate changes in the environment. The IPCC, A UN body of 63,000 reviewers and writers state that the latest findings on climate change announce code red for humanity and the planet. It is imperative that we act now, the small window of opportunity is rapidly closing.
She is impressed at the commitment Waikato District Council have shown towards taking action against climate change through their various district plans and strategies.
At a global scale, greenhouse gasses that are emitted into the atmosphere trap heat from the sun, creating a greenhouse effect and warming the temperature of the earth. This warming in turn has a flow-on effect on the delicate balance of ecosystems that inhabit this planet.
Governments and organisations around the world are now focusing on climate change mitigation and adaptation to slow the human causes of climate change. Climate change mitigation strategies are aimed at tackling the causes and minimising the impacts of climate change, like reducing emissions, whereas adaptation looks at how we can change our behaviours to reduce the negative impacts of climate change like diversifying crops for different climates.
Don’t forget to make your submission for the Raglan Food Waste Consultation which closes at 5pm, Friday 1 April. Visit the Waikato District Council website for more information: https://shape.waikatodistrict.govt.nz/raglan-food-waste-2022