The climate costs of our food system
The two major drivers of anthropogenic climate change are fossil fuels and food systems.
Of the total global fossil fuel usage per year, about 15% is linked to food production. Globally, food systems contribute to 30% of the total greenhouse gas emissions (GHG). Of these emissions, about 57% are associated with red meat and dairy (red meat refers to any mammalian meat for human consumption). In the UK, the agriculture sector was responsible for 11% of the total greenhouse gas emissions in 2020, of which red meat and dairy accounted for more than 70% of food consumption and production-related emissions. To comply with the Paris Agreement target of limiting global heating to 1.5°C it is critical to cut down emissions from the agricultural sector along with transitioning away from fossil fuels to cleaner sources of energy.
The scale of food waste
Despite producing enough food to feed 1.5 times the world population, around 1.3 billion tonnes of food is wasted every year, from harvest stages to consumer levels. Food waste accounts for 50% of the total food-related GHG emissions. The UN’s Sustainable Development Goal is to reduce global food waste and losses in production and supply by 50% by 2030 which would remove 25% of total food-related greenhouse gas emissions. Fruits and vegetables account for only 2.4% of supply-related food waste emissions while meat and dairy products account for 73.4%. In the UK, about 33% of the food waste is at the farm level and of the remaining about 70% of food waste is at the household level.
Climate-related extreme weather events such as flooding, wildfires, droughts, and storms increase the risk of food insecurity due to food crops being destroyed leading to reduced supply and higher costs. This would aggravate the burden on the lower socioeconomic groups who are already struggling with the cost of living crises and widen preexisting health inequalities.
Why methane from agriculture is a critical lever
There is a significant opportunity in the agriculture sector to swiftly reduce non-CO2 GHG emissions (such as methane and nitrous oxide) which would provide a buffer period for the world to equitably transition away from fossil fuels towards renewable energy. This is because methane and nitrous oxide decompose relatively rapidly as they have half-lives of 9-12 and 115 years respectively (while carbon released into the atmosphere can stay virtually forever). The digestive process in ruminant animals like cattle, sheep and goats and their manure is responsible for 32% of all agriculture-related methane emissions. The decomposition of food waste in landfills also produces significant methane. Methane is responsible for 30% of the total temperature rise we are facing now and with a 42% contribution, the agriculture sector is the largest source of man-made methane. In addition to being a potent trapper of heat, methane is responsible for the formation of ground-level ozone (a toxic air pollutant that causes over a million premature deaths annually, reduces crop productivity and harms ecosystems).
If both meat consumption and food waste are decreased by 50%, global food waste-related emissions can be reduced by 43%.