9.5.1 Effectiveness and plausibility of shifting eating patterns in developed countries
Shifts in eating patterns can make an important difference to global environmental impacts
Tilman and Clark (2014)
Adoption of Mediterranean, pescetarian and vegetarian diets has been modelled to have environmental benefits in terms of both lower GHG emissions and reduced land-use requirements, compared to both a 2009 “average” global diet, and an income-dependent predicted diet based on the 2009 average.
In high income countries, significant reductions in GHG emissions are possible without radical changes in eating patterns, although the role of meat in the diet does decline significantly. But above a certain level of emission reduction, it can be difficult for diets to meet nutritional needs and conform with current norms of acceptability
In high income countries, significant reductions without being too radical are possible
Adapted from Green, et al. (2015).
This study showed that if UK diets met WHO recommendations then associated GHGs would be reduced by 17%.
Further GHG reductions of up to about 40% would be possible via “realistic modifications to diets so that they contain fewer animal products and processed snacks and more fruit, vegetables and cereals”.
However, deeper cuts in emissions (e.g. beyond about 60%) would require acceptance of diets that are culturally very different from what we consume today – and beyond this level of reduction, our nutritional needs would not be met.
This observation illustrates the need for production-side changes (improving agricultural production, distribution and storage – see Chapter 4) and measures to address food waste, as well as for changes in consumption.
In high income countries, shifts towards national dietary guidelines can reduce GHG emissions, but per capita food-related emissions still remain high
Röös, et al. (2015).
The study on Swedish recommended healthy diets (see section 9.3) assumed that we each have a per capita emission space of approximately 1-2 tonnes CO2eq. as defined by IPCC – it also assumed that food consumption would take up 50% of these ‘allowable’ emissions.
All of the diets modelled here (a recommended Swedish diet (dark grey bar), an average Swedish diet (light grey bar), and a ‘paleo’ diet (middle grey bar)) would exceed this allowable GHG emissions per capita.
This again suggests that existing dietary recommendations may not yet be aligned with environmental sustainability, and that more needs to be done to reduce the environmental impacts of production (see Chapter 4).
9.5.2 Addressing nutritional challenges for rich and poor
The nutrition challenge is different for rich and poor people
The nutrition challenge is different for rich and poor countries. Many people in poorer countries need to increase their energy intake and food (and nutrient) diversity; people in richer countries need to decrease their energy intake and realign food diversity:
High consuming / overweight / rich people:
- The main issues are overconsumption.
- – Lower meat diets are likely to do no harm / could yield health benefits
- – Potential win-wins possible for health and the environment
Poor / hungry / malnourished people:
- The main issues are undernutrition, micronutrient deficiency, and livelihoods
- – Animal products are nutrient rich while livestock keeping can contribute to livelihoods and income
- – We need to develop food production systems that maximise nutrition at minimum environmental cost
Rich and poor people alike in developed countries may often consume high quantities of meat and dairy, as do many rich people in developing countries. These groups will need to reduce or moderate their meat and dairy consumption
There is a need to integrate nutrition, climate change and environmental policy, a view which is largely consistent with the contraction and convergence concept introduced in Chapter 4.
9.5.3 Important uncertainties remaining
Important uncertainties remain
Important uncertainties remain in our understanding of SHEPs:
Production-consumption interactions are complex. Production methods influence environmental and/or nutritional profile and affect cost and availability which influences consumption (see Chapter 4).
Rebounds and leakages can influence consumption: changes in production or consumption in Country A can trigger changes in consumption or production in Country B.
Climate change models predict disruptions to food supply, but greater understanding is needed into how these will impact consumption (see Chapter 5).
Currently GHGs are often used as a proxy for environmental impact. We only have a limited understanding of how water issues, different qualities of land use, impacts of food production on biodiversity, and resilience & adaptability – and the interactions among all these concerns – would shape a more complete understanding of SHEPs. We also lack understanding about the cultural and livelihoods dimensions of sustainability.
Most of the research on SHEPs has focused on developed countries, whereas significant consumption changes are occurring in low-middle income countries. It is important to understand these changes and explore how evolving dietary pathways might be reoriented in more sustainable directions.
- How might future changes in production methods influence demand? (see Chapter 4)
- How might different assumptions about the role of grazing livestock in sequestering soil carbon alter our conclusions about the role of ruminant meat in SHEPS?
- How might changes in production or consumption in one country trigger changes in consumption or production in another (via imports and exports)?
- How will climate change itself impact upon food production – not just yields but also nutritional quality? (see Chapter 6)
- What about sustainability metrics that go beyond GHGs, water and land use?
- What sustainable and nutritionally adequate dietary pathways might be appropriate for low income countries?