When we talk about the big drivers of climate change, we often go to our energy, transportation, and manufacturing systems. Yes, these are all big areas we need to tackle. But there’s another that tends to fly under our radar. Food.
Every year, Canadians create an estimated 35.5 million tonnes of food waste. Food waste not only wastes resources and money, but when disposed of improperly (i.e. in a landfill), it also creates methane emissions. Methane is a much more harmful greenhouse gas than carbon dioxide (about 25% worse!). And while some of Canada’s food waste gets composted, a lot of it doesn’t. In fact, wasted food makes up about 23% of all the waste we send to landfills, contributing 56.5 million tonnes of greenhouse gas (GHG) emissions (mostly methane) into our atmosphere.
But there’s another type of waste in the food value chain that happens long before the cheeseburger hits your plate. And that’s at the farm level. Animal waste (e.g., cow and pig manure), for example, also produces methane. In fact, methane from manure makes up about 10% of Canadian agricultural GHG emissions overall. To put that in perspective, cow poop contributes about one-fifth of the GHG emissions embedded in a glass of milk (spilling it might be worth our tears after all).
It’s clear that achieving Canada’s climate goals means addressing food and farm waste. This is critical, not only to address environmental concerns, but economic ones as well. According to 2019 research by Second Harvest and Value Chain Management International, the value of food – from farm to fork – lost or wasted every year is worth $49 billion.
Tackling this challenge looks like reducing waste at its source and also finding innovative ways to repurpose waste so that it helps, rather than harms, people, our economies, and the climate.
This is where “circular economy” solutions can play an important role. In short, circularity is about moving from a “take-make-waste” model to one in which we literally “close the loops” on the life cycles of everything we use.
Can that work with food and farm waste? Yes! In fact, there are a number of circular strategies that the agri-food system can use, and is already using, to help reduce waste and pollution, reuse resources, and regenerate nature. These include regenerative agriculture and sustainable aquaculture practices, shortening food supply chains, and food rescue and recovery programs (see this Circular Food Solutions in Canada report for lots of great case studies).
But one opportunity we could do a much better job scaling in Canada is with agricultural biodigesters.
So, what’s a biodigester? You can think of them as big, artificial “stomachs” (i.e., containers) that can hold and digest food waste, animal manure, and other organic materials. These containers provide an anaerobic environment where microorganisms break down the organic materials (e.g., food waste and manure). The microorganisms produce two useful by-products in the process: 1) biogas (which can be upgraded to renewable natural gas (RNG)); and 2) a nutrient-dense fertilizer.
Biogas can be used on-farm to reduce on-farm energy costs, as well as a substitute for other energy forms that may produce more GHG emissions. Alternatively (or additionally), biogas can be sold back to a community’s electricity grid and/or upgraded to RNG and inserted into the natural gas pipeline to displace fossil fuel-derived natural gas, creating additional revenues for farmers.
Meanwhile, the nutrient-dense digestate can be used as a fertilizer and spread on agricultural lands or sold to other farmers. This reduces the cost for farmers in buying fertilizers while also increasing soil health – in turn, enabling stronger crops.
In this example, not only are traditional waste streams from agriculture being reduced, but they are also being transformed into valuable products that generate economic and environmental benefits. And rather than taking natural resources endlessly until the soil health on a field is depleted, these products give back to the earth and continue a system of nutritious food and healthy landscapes.
While agricultural biodigesters are a great opportunity for farmers and the environment alike, farmers are having to overcome a number of obstacles to implement these solutions on-farm. In the first season of The Ag Podcast, George Dick, the owner of Dicklands Biogas in British Columbia, spoke about the challenges he’s currently facing. From regulatory challenges, to troubles obtaining enough organic feedstock inputs for his biodigester, to having to stay on top of evolving information on biodigesters, George will be the first to tell you that it isn’t easy. In fact, of the ~75,000 farms with animals in Canada, only 45 farms have agricultural biodigesters – highlighting just how hard it is for farmers to access this solution.
We need government supports to help address these challenges and create a stronger case for farmers to implement biodigester solutions, especially given the essential role biodigesters play in tackling hard-to-abate methane emissions. In our E-book, ‘Taking Action on Methane Emissions - Untapping Canada’s agricultural biogas opportunity,’ we identify the three ‘must-have’ capital and revenue supports that federal and provincial governments can implement to catalyze biodigesters. Once these supports are in place, capacity building, technology innovation, and feedstock security policies can follow.
With these supports, we can build out a Team Canada approach to agricultural biodigesters, ensuring that the potential of biodigesters is turned into real economic and environmental impact for farmers, their communities, and Canada as a whole.