Clean Your Plate
Food waste contributes to greenhouse gas emissions
A startling new report from the UK has demonstrated the impact food waste can have upon a country’s carbon emissions and water footprint.
The report, published by WWF-UK and the UK government’s Waste and Resources Action Programme (WRAP), says that potentially avoidable food waste represents up to 64 gallons of water per person per day and 727.5 pounds of CO2 per person per year.
Photo by Gunnar Grimnes
This means that around 6 percent of the UK’s water footprint and 3 percent of its carbon emissions come from food waste. That’s roughly equal to adding 25 percent more cars on the road!
The amount of food we waste is shameful. It’s among the most unsustainable aspects of our high-consumption lifestyle. Curbing it will have a significant impact in improving our overall environmental impact.
How do these figures stack up against the rest of the world? To answer that question I’ve looked at the US and China.
There are no directly comparable figures, mainly because the UK study is the first of its kind in the world. However we can extrapolate some figures using published food and waste figures and water footprint and carbon emissions datasets.
A commonly quoted figure is that 40 percent of US food is wasted. That, by anyone’s measure, is a staggering amount.
The EPA has published a comprehensive set of figures for 2009 showing the CO2 emissions of each sector, including embedded energy use. These show that 206 million tons of CO2 come directly from agriculture, plus an additional 53 million tons from food waste in landfill (which is 20 percent of the total). Food waste in the US therefore produces a total of 260 million tonnes of CO2 emissions ‑ 4.4 percent of the country’s overall carbon footprint. This is equivalent 2,044 pounds of CO2 per person per year, or a 41 percent increase in the number of cars on the road.
Only 58 percent of the US’ 696 billion cubic meters/year water footprint comes from agriculture, a relatively low proportion compared to other countries. However because the rate of food waste is so high, 163 billion cubic meters of water, or 23 percent of the country’s total usage, is consumed unnecessarily every year. In terms of per person use, that amounts to a whopping 420 gallons per person per day.
According to figures published by the Laboratory of Organic Geochemistry (PDF), in 2009 around 62 million tons of food waste went to landfill in China. Further figures from the National Bureau of Statistics (PDF) indicate total food consumption in 2004 was 905 million tons. Which means China wastes about 7 percent of the total food it produces.
A report prepared for the US Congress (PDF) in 2008 estimates that 14 percent of China’s overall carbon emissions come from agriculture. Combining these figures means that only 66 million tonnes CO2, or 1 percent of its overall emissions is generated each year from China’s food waste. However, this does not include energy emissions from agriculture or from food waste in landfill, which is a comparatively lower 115 pounds of CO2 emissions per person per year. Agriculture accounts for over 85 percent of China’s 883 billion cubic meters/year water use, but because the rate of food waste is much lower than the US the amount of water wasted is also low: only 54 billion cubic meters of water, or 6 percent of the total. In human usage terms, that’s about 30 gallons per person per day.
I must emphasise these calculations are my own and don’t have any of the subtleties a proper scientific study will contain. In addition, the UK report differentiates between avoidable and unavoidable food waste but only total food waste figures are available for the US and China.
That said, it’s obvious that food waste has a significant impact upon a country’s carbon emissions and water footprint. By taking greater care with the food we produce and consume, our environmental impact would be lessened much more than many of the industrial and energy solutions currently being proposed.