It is axiomatic that we live in the Anthropocene, which in my view is a post-Holocene epoch exemplified by mankind’s unchallenged dominion over the earth. Our capacity to change the chemical, physical and biological attributes of our planet has been likened to the aftermath of a volcano or earthquake or glacier.
At the heart of the dysfunction of our relationship with our home, planet earth is the structure of the modern economy and our dietary choices, especially high consumption of animal products in developed countries, and now increasingly in developing countries.
Our addiction to fossil fuels, as well as a surge the in demand for food, fodder, biofuels, and meat products has precipitated unprecedented emissions of carbon dioxide, methane and nitrous oxide. These gases are referred to as greenhouse gases because when they are released into the atmosphere they trap solar radiation, raising regional and global temperatures and alter entire climate systems. The effects of a changing climate system are manifested in extreme weather – droughts, floods and heat waves – rising oceans, hunger and conflict over scarce resources, as well as emerging and re-emerging infectious diseases.
Globally, efforts aimed at slowing down global warming have been limited to regulatory mechanisms and financial incentives necessary to reduce emissions from industry, energy and transportation. Moreover, we have been pre-occupied with the effects of global warming on agriculture. Until recently the contribution of the global food system to greenhouse gas emissions and global climate change has receive d tepid attention.
It is estimated that agriculture contributes between 19 and 30 percent of global greenhouse gas emissions. Land use change, especially conversion of forests to pasture and cropland in the tropics releases more carbon dioxide annually than does every bus, car, train and truck in the world. According to the UN Food and Agriculture Organization (FAO) methane accounts for nearly half of total agricultural emissions. The largest source of methane is the digestion of organic materials by livestock. Agriculture generates 65 percent of anthropogenic nitrous oxide and 35 percent of methane, which have 289 times and 25 times the Global Warming Potential (amount of heat trapped per unit mass of gas) of carbon dioxide respectively.
FAO has projected that cropland and pasture-based food production will increase by 60 percent by 2050 to meet rising global food demand owing to population growth and affluent diet preferences. This implies that cropland must expand by circa 42 percent, fertilizer application will increase by 45 percent and tropical forest cover will decline by a further 10 percent to create land for agriculture.
A new study, “Importance of food-demand management for climate mitigation”, led by University of Cambridge scholars and published in the journal Nature Climate Change warns that an increase in global food demand would result in a whopping 77 percent increase in greenhouse gas emissions from agriculture. Clearly, to push for more food production by adding more land, more technology, more inputs and more livestock could erode critical planetary boundaries and push vital earth systems beyond critical thresholds into alternative but sub-optimal states.
Meeting global food supply needs must not only happen though increased agricultural production. Options that address the demand side of global food must be on the table. In this regard, healthier diets through consuming less meat products, reducing food waste and cutting food losses (both pre-and-post-harvest) must be part of a combination of solutions to ensure food security while avoiding dangerous climate change.
For example, reduction of global meat consumption could halt deforestation and achieve significant cuts in greenhouse gas emissions. More importantly, the 1 billion tonnes of barley, wheat, oats, rye, maize and sorghum that go into livestock feeding troughs to produce meat could nourish half of the world’s 7.2 billion population. Moreover, it is estimated that the amount of food wasted in the developed world, 2.3 billion tonnes, is equivalent to the entire food production in Africa. FAO estimates that eliminating post harvest losses could bring an additional 14 million tonnes annually to Africa’s cereal ledger.
Climate change mitigation policies must not focus solely on energy and transportation sectors. By consuming less meat, eliminating waste and reducing post harvest losses, our food system can be part of the solution to the climate crisis, complementing efforts to de-carbonize our economies. Moreover, adopting agroforestry practices offers significant carbon sequestration benefits, enhancing our capacity to achieve food security without increasing greenhouse gas emissions.