In his book Drawdown, Paul Hawken lists food waste as the third-largest combatable cause of climate change. His research indicates that with a 50% reduction in food waste by 2050, we could reduce emissions equal to 26.2 gigatons of carbon dioxide, or 8% of greenhouse gases.
One-third of food produced doesn’t make it from farm to fork. In the USA, willful food waste occurs when foods are rejected because they are unattractive or when we buy too much. Over 40% of our food is thrown out. I’ve never left a party where there weren’t tons of leftovers, and yet ….
One night in Santa Rosa last November, my friend Harmony and I were returning from an event at the junior college with leftover food for the folks living under the 9th Street overpass. There were 25 encampments there that night. I asked who was hungry and folks pushed this one woman forward with the cry, “Feed her first. She hasn’t eaten in three days.” Hungry as they were, they made sure she was fed first.
According to the film Wasted, 90% of food waste goes into the landfill where, deprived of an oxygen flow, it takes years (even decades) to rots, releasing greenhouse gases as it does so.
The first thing you should do when you have too much food is feed other people. In the United States, 1 in 6 Americans are food-insecure, meaning they don’t know where their next meal is coming from. This leads to serious health issues: 1 in 5 American children don’t get enough nutrition during their developing years, endangering the future of America.
Before you go shopping, make a menu to use as the basis of your grocery list. Never shop for food when you’re hungry. Market expiration dates, except sell by, are about peak quality, not safety. Too much food gets thrown away over confusion about these labels. There is no need to throw away as much food as we do: There are parts of animals and plants that we don’t usually eat that, with some culinary creativity, we could, and we can eat leftovers, freeze food, and feed others.
When extra food is no longer useable for humans, feed it to animals. Sort animal food separately. Farmers will boil it at 100°C to kill bacteria before serving it to their livestock. If food waste is too decayed for humans or other animals, the next step is to capture the carbon dioxide in a waste-to-energy system and then compost the leftover mash. There are about 800 waste-to-energy systems, which are cheaper than fossil fuel or nuclear power plants, in more than three dozen countries around the world. These closed systems use anaerobic digesters to convert organic waste into biomass fuels, which are carbon-neutral. Plants absorbed carbon dioxide when they were alive, which offsets emissions when they’re used as fuel. We can also use the mash for carbon farming.
With carbon farming, a single application of a half-inch of compost on grazed rangeland will increase soil water capacity to 26,000 liters per hectare and soil carbon sequestration by at least one ton per hectare per year for thirty years. Compost decomposition provides a slow release to the soil, which, with improved soil moisture conditions, leads to increased plant growth. More plants leads to an increase in transfer of carbon dioxide through the plant to the soil, yielding additional soil carbon and water holding capacity.
In short, addressing food waste is one of the ways we can and must reduce greenhouse gas emissions today.