- To reduce the amount of waste going to landfill. Estimates suggest that as much as 40 per cent of household waste going to landfill is organic material from the food system. If this can be managed in other ways, such as by composting, the considerable expense of siting new landfills can be postponed.
- To reduce emissions of an important greenhouse gas from landfills. In a landfill much of the organic material will decompose to produce methane, a gas that is at least 28 times more powerful in its greenhouse effect than carbon dioxide. Most national and regional climate change mitigation strategies include efforts to reduce methane emissions.
- To provide a mechanism to improve the organic content of soils. As far back as 1984 the Senate of Canada Committee on Agriculture, Fisheries and Forestry reported that as much as 40 to 60 per cent of the organic matter present in virgin prairie soils has been “used up” by farm production. Similar numbers almost certainly apply to other parts of Canada. Loss of soil organic matter reduces the ability of the soil to hold moisture and lowers the its productivity. The incorporation of compost into soil helps to replenish the soil organic content, improves soil productivity and acts as a form of carbon sequestration to help reduce the carbon dioxide content of the atmosphere and hence the effects of climate change.
- To help replenish the plant nutrient content of soils. Growing of plants and regular removal of the produced biomass reduces the plant nutrient content of the soil and hence the productivity of the land. While the nutrient content can be replenished with mineral fertilizers the availability of some of these fertilizers is beginning to be challenged. The addition of compost to the soil helps to replenish the nutrient content and reduce the need for mineral and synthetic fertilizers.
With less than half of the food and organic waste produced in Canada going to composting, much of the rest goes to landfill and incineration. The reasons are primarily economic even though there is evidence that composting and land application of composted food waste is cheaper in the long run than landfilling of food waste.
Plastic packaging problems
Compostable plastic packaging systems are available but are having some difficulty winning market access for a number of reasons. Composters claim that their systems were not designed to handle compostable plastics and it will be expensive to upgrade them. Some composters in Canada and many in Europe utilize composting technologies that can effectively handle compostable plastics.
Other composters claim that end users and composting systems cannot effectively differentiate between compostable plastics and conventional plastics that are not compostable. Technologies exist to reject non-compostable plastics from the composting stream; colour coding and clear labelling of plastic food packaging is being used in some North American jurisdictions to differentiate compostable from non-compostable packaging.
There is also concern among composters that some non-compostable plastic packaging that may mess up their composting system is being labelled as compostable or biodegradable to give it a marketing edge. There are three certification systems in North America and a handful of others around the world for compostable packaging and almost everyone, except the scammers, seems to agree that it should be made illegal to label a package as compostable or biodegradable unless it has been certified by one of these agencies. However governments seem reluctant to move on this action to prevent misleading labelling.
Finally, some composters also seem to be concerned that their composting plants will be overwhelmed by compostable plastic packaging materials if these become more common. Certification agencies agree that compostable plastic packaging should be used only for food waste collection, such as kitchen catchers, where it clearly provides a superior product and eliminates the “yuck” factor, and packaging of those food products with which the packaging material ends up contaminated by food waste and therefore effectively and economically unfit for recycling.
Next steps and solutions
Future bans on some types of plastic packaging seem likely to lead to increased spoilage and food waste. Several European countries are showing the way in which compostable plastic packaging systems can keep food spoilage and waste to a minimum while reducing, and eventually eliminating, the release of plastic waste into the environment. With its vast expanse of agricultural land, including some poor quality agricultural land that provides an excellent opportunity for production of non-food biomass that can be used to manufacture certified compostable bio-based packaging and other compostable plastic materials, Canada would seem to be well-placed to become a leader in development and manufacture of compostable plastic materials.
To achieve real solutions our governments need to commit to organics collection and composting being a service to industry and consumers rather than a barrier to introduction of materials that hold considerable promise of environmental benefits in reducing climate change and landfilling.
Colin Isaacs is a chemist with practical experience in administration, a municipal council, the Ontario Legislature, a major environmental group, and, for the past three decades, as an adviser to business and government. He is one of the pioneers in promoting the concept of sustainable development for business in Canada and has written extensively on the topic in the popular press and for environment and business platforms.
Featured image credit: Gary Butterfield/Unsplash.