My first blog introduced the thorny questions facing food sustainability scholars who want to inform food policy and everyday decision making. The second blog then examined the food system through the lens of COVID-19 to discuss some of the socioeconomic, health, and justice dimensions of food sustainability. This month, I’m going back to basics a little bit to define what exactly is meant when we talk about the food system and to discuss how food systems contribute significantly to local- and global-scale environmental impacts.
Food systems, especially when we consider large-scale global food systems, are too complex to define succinctly in one sentence or diagram, but this simplified map of the food system does a good job of showing the input/output flows and interactions between the different domains that together make up the food system: agricultural, economic, social and environmental domains.
Source: http://www.cfet.org/resources/
Some of these domains immediately spring to mind when we think about food systems, for example the farming stage and food retail settings. The economics of global food markets, the transport and processing of food, global and local food policies, environmental impacts, and the labour of farmers and farm workers are much more invisible or inaccessible to us, but these are all key parts of the food system. Missing from this diagram is the harvesting of wild species for food, most notably the substantial and growing global harvest of marine fish and invertebrates.
Each of these domains contains key drivers which shape food systems, and thus food systems are dynamic, with changes in one domain resulting in changes in other parts of the system and at different scales. Trying to figure out how the food system should be changed to make it sustainable is, therefore, a tricky undertaking, fraught with complexity and uncertainty. Despite these limitations, systematic analyses of food systems have yielded important insights into how the provisioning of our food is contributing to environmental impacts. And the research shows that the impacts are significant.
The food system, in particular agricultural systems and the harvest of wild food species, has been identified as a major driver of biodiversity loss globally. The 2019 IPBES Report on Biodiversity and Ecosystem Services identified land use change and the over-exploitation of marine resources as having the greatest impact on terrestrial and marine biodiversity globally. Land clearing and deforestation and the conversion of wetlands and grasslands to agricultural landscapes are leading to an ever-increasing loss of habitat. Currently, agricultural systems cover a staggering ~43% of ice- and desert-free land and account for an estimated 66% of freshwater withdrawals. Furthermore, terrestrial, marine, and freshwater habitats are being degraded by agricultural production through eutrophication, acidification, toxic pollution, and the introduction of invasive species. Together, agriculture and over-exploitation of wild food resources are estimated to have contributed to 75% or even as high as 80% of the species losses during the past century.
The food system is also a big contributor to climate change. Globally, the food system is estimated to account for approximately 26% of humanity’s total greenhouse gas (GHG) emissions. The farm stage of the food supply chain is the largest emitter of GHGs, contributing an estimated 61% of the food system’s GHG emissions. If GHG emissions associated with deforestation for agricultural expansion are included, farm stage impact jumps to 81% of food system GHGs. The farm stage also dominates the food system’s acidification and eutrophication impacts, contributing 79% and 95%, respectively.
These are heady realities to grapple with. In 2019 the IPBES Report on Biodiversity and Ecosystem Services and the IPCC’s Report on Climate Change painted a bleak picture, showing that human activities are driving biodiversity loss and climate change at unprecedented rates, and indicating that our window of opportunity to act is beginning to close. Unfortunately, as the research discussed here shows, the systems currently in place to keep us all fed are key contributors to global environmental impacts. These same global changes threaten food production and wild food harvest and in turn undermine our ability to feed our growing human family. But, unlike so many of the things humans consume, food and water are non-optional. We need them daily, and access to nutritious food and clean water are fundamental human rights. Too many of our fellow humans already go hungry or suffer from malnutrition.
So what can we do? Obviously a big rethink and a big shift are needed – a shift that transcends sectors and national borders. But for the balance of this series of blogs, I’ll be focused on discussing solutions that are specific to food system changes. How can we change how we produce food? How can we change how we eat? How can we face these challenges while scaling up to feed an estimated ten billion people by 2050? Brilliant and thoughtful people the world over are tackling these questions, and the good news is that, while it won’t be easy and we don’t have everything figured out, there are things we can and should do to make our food systems more sustainable.
Header photo by Johny Goerend on Unsplash
