Chapter 8 summary
Consumption - the missing link towards phosphorus sustainability
Chapter authors: Geneviève S. Metson, Will J. Brownlie, Julia C. Bausch, Malin Jonell, Kazuyo Matsubae, Frank Mnthambala, Caroline Schill, Elizabeth Tilley. • 10min read
Chapter highlights
Supporting low levels of animal product (meat, dairy, and eggs) consumption and food waste can significantly reduce the impacts of unsustainable phosphorus use. In addition, consuming products grown with good on-farm nutrient management practices, including phosphorus recycling can further reduce impacts. These changes can contribute to achieving multiple United Nations’ Sustainable Development Goals related to improving human and environmental health.
Introduction
What is the role of consumers in phosphorus sustainability?
While it is widely recognized that fertiliser companies, farmers, and waste managers all play crucial roles in improving phosphorus fertiliser use and recycling, the role that consumption plays in the phosphorus cycle is often overlooked. Many consumers feel disconnected from how their food is produced and processed, an increasing trend in light of global urbanisation. Although most consumers do not physically control how much phosphorus is used to fertilise food crops or where their waste goes, they still have great influence over the phosphorus cycle through their individual and collective purchases, waste management, and the policies they support.
Individual citizens and families affect phosphorus sustainability in many ways, however, the largest impact stems from what they eat. Around 85% of all mined phosphorus is used in food production, and over the last 60 years, 38% of the increased use of mineral phosphorus fertilisers can be attributed to global diet changes. This increase is predominantly related to increased consumption of animal products (e.g. meat, milk, and eggs), especially in wealthier countries where per-capita consumption is often higher than is recommended. If this trajectory continues, we will not meet most of the United Nations’ Sustainable Development Goals. With more humans on the planet than ever before, and still rapidly increasing in several regions, judicious resource management is essential for food and water security.
Consumers can play a key role in reducing the net amount of phosphorus in the anthropogenic phosphorus cycle by reducing meat consumption and food waste. Consumer preferences can also affect which sources of phosphorus are used to produce their products, and thus can support more recycling. Though individual food habits are shaped by a complex set of drivers, they are not set in stone. A holistic strategy is needed to make consuming low-impact foods easier, cheaper, and more desirable for the public.
Governments and food processors could contribute to achieving this through education, taxes (i.e. taxing negative externalities), altering food labels and food prices, and by optimising subsidies to promote a less animal-intensive food system, build greater capacity to use recycled phosphorus fertilisers, and decrease waste throughout the food chain. Such holistic transformations will contribute to several of the United Nations’ Sustainable Development Goals (SDGs), including poverty alleviation (SDG1), zero hunger (SDG 2), water/sanitation (SDG 6), responsible consumption (SDG 12), climate action (SDG 13), life in water (SDG 14) and life on land (SDG 15).
In the following sections, we summarise the key challenges to increasing phosphorus sustainable consumption behaviours and suggest potential solutions to overcome them.
Key issue 8.1
Animal products have high phosphorus footprints
The challenge
The production of meat, dairy and eggs require disproportionately high amounts of mineral phosphorus fertilisers. Under 2011 global farming practices, it took 16 times more mineral phosphorus fertiliser to produce 1 gram of beef protein than 1 gram of legume/pulse protein.
The solution
Wider adoption of healthy diets with low to moderate amounts of meat and dairy (especially low in red meat) could radically reduce demand for mineral phosphorus fertilisers and thus phosphate rock mining. While some demographics could benefit from increased access to animal products, large gains can be made from reducing meat consumption in countries that already consume more than is recommended. The global adoption of a vegetarian diet would cut both fertiliser needs and eutrophication effects by 50%. Although this may be unrealistic, it indicates the major influence of diet change on the global phosphorus cycle.
Key issue 8.2
Consumption of animal products is increasing
The challenge
The average diet has seen a 38% rise in phosphorus footprint over the last 50 years; this can mostly be attributed to the increased consumption of animal products. A remarkable increase has occurred in China and Brazil; however, their footprints are still below the USA and other industrialised countries (e.g. average per capita protein intake in the EU is about 70% higher than recommended). Economic development correlates with increased consumption of animal products. Some populations still require a more diverse and calorie-rich diet.
The solution
The widespread adoption of healthy, regionally appropriate diets that are rich in plant-based foods and sustainable aquaculture produce is compatible with sustainable phosphorus management, and this must be promoted in a culturally sensitive way. Sustained communication, along with global and regional structural changes to food systems can help consumers adopt diets that are good for them and the environment.
Key issue 8.3
Food loss and waste is high across the globe
The challenge
Globally, 23% of nutrients in fertilisers are used to produce products that are then lost in agricultural and food wastes. The loss at each stage, from farm to fork, differs among regions. Generally, waste is higher on a per-capita basis in industrialised countries, whilst in lower-income countries, losses are driven by insufficient infrastructure.
The solution
We can reduce food loss throughout food production, retail, and consumption sectors. Most food loss in low-income countries occurs before products reach consumers; meanwhile wealthier nations waste more food in retail and at home. Efficient strategies to reduce waste will target the most wasteful, with support underpinned by evidence that quantifies the benefits of change.
Key issue 8.4
Changing consumer food habits is difficult
The challenge
Whilst a shift towards more phosphorus-sustainable diets and waste management practices is required, a complex network of conditions must be met for an individual to change behaviour, which varies by region, country, town, and even family. Raising awareness of negative environmental and/or health impacts (including phosphorus sustainability issues) of certain food choices alone is not enough to change behaviours. People’s resources and capacity to change need to be considered as well.
The solution
We can make being ‘sustainable’ easy and rewarding for consumers. It should be easy and affordable for everyone to make healthy diet choices, decrease food waste, and support the safe use of recycled phosphorus from organic wastes (e.g. food waste and excreta) in food production. Incentive structures (including ‘health nudges’ and ‘choice editing’) embedded in food systems must be transformed to make phosphorus-sustainable food choices the ‘default’ option.
Key issue 8.5
Unsustainable pricing models may slow a transition to sustainable practices
The challenge
There is a disconnect between what a consumer pays for food and the true ‘costs’ of food production. The costs involved in mitigating environmental degradation and biodiversity loss from phosphorus losses, and in developing more phosphorus sustainable agriculture systems, are not covered in the price of food products.
The solution
We can develop policies that encourage and support consumers to lead sustainable phosphorus lifestyles. Developing economic and regulatory policies that encourage and support high recycling rates, low animal product consumption and low waste production will be necessary for sustainable change. This may involve setting high goals for organic waste recycling, direct taxes on animal products, or decreasing subsidies that affect the price of meat.
Conclusion
The public, as food consumers, waste producers, and decision-makers, play a critical role in the sustainability of the phosphorus cycle. However, sustainable products must be readily available for consumers to choose from, which in some cases will require the greater collaborative efforts of policymakers, institutions (e.g., schools, hospitals), and food processing, distribution, and retail services (e.g., restaurants). The challenges identified above must be tackled across different scales because patterns of food consumption and waste production occur in the context of local to global policies, infrastructure, and culture, and stem from the decisions and actions of all stakeholders; from policymakers, institutions, and businesses (e.g., food processors, grocery stores, and restaurants), to households and individuals. Different stakeholders can thus participate collectively in making changes for better phosphorus management. Although different strategies might be required for different regions, the goal is the same: support both environmental quality and human health in the long term through better consumption practices.
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The full chapter contains references to the evidence provided above and acknowledgements of images.
Suggested citation for this chapter: G.S. Metson, W.J. Brownlie, J.C. Bausch, M. Jonell, K. Matsubae, F. Mnthambala, C. Schill, E. Tilley. (2022). Chapter 8. Consumption - the missing link towards phosphorus sustainability, in: W.J. Brownlie, M.A. Sutton, K.V. Heal, D.S. Reay, B.M. Spears (eds.), Our Phosphorus Future. UK Centre for Ecology and Hydrology, Edinburgh. doi: 10.13140/RG.2.2.36498.73925