3.1. Benchmarking the Environmental Impacts of the Average Swedish Diet Relative to Global Boundaries
The environmental impacts of the average Swedish diet benchmarked relative to the EAT-Lancet
boundaries are illustrated in Figure 2
and presented in absolute numbers in Table 2
, together with per capita boundaries.
It was found that the average Swedish diet exceeded the allowed boundary for overall emissions of GHGs by more than three-fold. The boundary was transgressed with regard to emissions of CO2, CH4 and N2O. Of the 2.2 ton CO2e emitted per capita and year, emissions of CO2 accounted for 0.92 ton (~41%), but should be zero. Emissions of CH4 and N2O together accounted for 1.3 ton CO2e (~58% of total emissions), but should be below 0.68 ton CO2e. Emissions of HCFC-22 (0.01 ton CO2e) made up a minor fraction (<1%). Hence, even if emissions of CO2 were reduced to zero, the boundary would still be exceeded by almost two-fold.
With regard to cropland use, the average diet required use of almost twice the cropland area per capita compared to the EAT-Lancet
boundary. The results on GHG emissions and land use were similar to those reported by Röös et al. [14
], who found that the average Swedish diet far exceeds the sustainable level of climate impact (2.5-fold the limit) and also transgresses the identified sustainable level for land use (by ~1.1-fold the limit).
Concerning application of nutrients, the Swedish diet transgressed the boundary for both nitrogen and phosphorus by more than four-fold. For consumptive water use on the other hand, the Swedish diet performed well below the boundary. For rate of extinctions, the Swedish diet caused six-fold more extinctions than the boundary. It should be emphasised that the results for extinction rate heavily depend on the choice of amortisation period for the extinctions, see discussion in Section 3.4
. For all categories where the boundaries were transgressed, the impact was well above the zones of uncertainty (Table 2
Comparison of our Swedish results against the corresponding results given for the global food consumption as assessed by the EAT-Lancet Commission revealed similar trends, with current (2010) global consumption exceeding the safe operating spaces for climate, phosphorus cycling and biodiversity loss while current freshwater use lay below the boundary. With regard to nitrogen cycling, the 2010 impact was above the boundary but within the range of uncertainty for the boundary. For cropland use, the global food system was still, in 2010, within the boundary but with increasing population up until 2050, the boundary was projected to be transgressed on the global level if measures to reduce waste, improve production or change diets are not imposed. However, as was seen in the results from the present study, the boundary is already exceeded for the Swedish diet.
3.2. Relative Contribution of Foods to Environmental Impacts of the Average Swedish Diet
provides an illustration of the environmental impacts broken down per kg of food on the Swedish market and Figure 4
presents the environmental impacts per capita from the overall diet and the relative contribution from different food groups to each impact category. For more detailed results, see Supplementary Material (Tables S2 and S3)
Looking at larger food categories, animal products contributed the largest share of GHG emissions (about 67%), 18% were caused by the consumption of sweets, snacks and drinks (excluding milk) and the remaining 15% were caused by the consumption of other plant-based foods (Figure 4
). A similar trend was seen for cropland use per capita and use of nitrogen, with animal products causing the largest impact (60% and 77% respectively). With respect to phosphorus application, animal products contributed 38% of the overall impact. The consumption of sweets, snacks and drinks contributed between 12% and 42% of the overall impacts for the mentioned categories, with the lowest contribution for nitrogen application and the highest for phosphorus. Other plant-based products contributed between 10% and 19% of the overall impact for these categories (lowest for application of nitrogen and highest for phosphorus). Sweets, snacks and drinks as a group, thus made the highest contribution to phosphorus application. This group also made the highest contribution to species extinction rates with 45% of the overall impact whereas other plant-based products and animal products contributed 26% and 27% of the overall impact respectively. Finally, for consumptive water use, the contribution was highest from plant-based products with 48% of the overall impact. Animal products and sweets, snacks and drinks caused similar impacts with 28% and 24% of the overall impact respectively.
The low contribution from many plant-based foods to the environmental impacts of GHG emissions and cropland use (Figure 4
) is mainly explained by the relatively low impact per kg for products such as fruits, leafy vegetables, root vegetables and cereals (Figure 3
), which is in line with earlier findings [7
]. Important exceptions with regard to GHG emissions and cropland use per kg were found, e.g., for coffee, cocoa and vegetable oils (especially olive oil), for which cropland use made an important relative contribution to the overall impact (Figure 4
Sweets, snacks and drinks and the category of other plant-based foods contributed relatively more than animal products to the categories of extinction rate, consumptive water use and phosphorus application (Figure 4
). For biodiversity, this was explained by the high impact per kg of food caused by plant-based products such as vegetable oils (especially olive oil), fruits, nuts, coffee, cocoa and rice (Figure 3
). Together with high consumption of these foods, this led to important overall impacts (Figure 4
). The high biodiversity impact per kg of olive oil, coffee and cocoa was mainly explained by the high cropland use, while for products such as bananas, which are imported from South and Central America, the occupation of land for production in these areas caused high impacts due to high biodiversity loss per occupied m2
. In general, animal products such as beef caused low biodiversity impacts per kg despite high land use (Figure 3
), due to that most livestock production for the Swedish market take place on relatively biodiversity-poor land (Sweden and Northern Europe). However, the impacts on biodiversity loss would change considerably if production were to take place in countries where the occupation of land causes higher biodiversity loss per occupied m2
in comparison to countries that currently represent the largest shares on the Swedish market, such as Sweden, Ireland, Poland and Germany. An important exception was seen for lamb, which was found to have the highest biodiversity impacts per kg (Figure 3
) and also gave a high contribution to the overall impact (Figure 4
), despite low consumption rates. This was explained by its high land use (especially pasture), together with the high biodiversity loss from occupation of land for sheep production in New Zealand, a country which represents about 20% of the Swedish market (Supplementary Material
Freshwater consumption per kg was especially high for nuts (almonds in particular), rice and vegetable oils (Figure 3
), as also seen in its relative contribution (Figure 4
). High freshwater consumption per kg was also seen for coffee and fruits in comparison with other plant-based products (Figure 3
). An important share of the relative contribution was made by fruits and leafy vegetables (Figure 4
), because, e.g., a large proportion of fruits are imported from areas where high irrigation levels are often required (see Supplementary Material
). With regard to Swedish products, irrigation is generally carried out on a small proportion of Swedish agricultural land, with crops that often require irrigation including root crops, vegetables and fruits [79
]. Grains and ley for animal feed and pasture are seldom irrigated, either in Sweden or in other production countries [69
]. Due to freshwater use for rearing animals [68
], animal-based products still had higher consumptive freshwater use per kg than many plant-based products (Figure 3
With regard to phosphorus application, fertiliser application was generally low per kg for plant-based products except for cocoa, coffee and olive oil (Figure 3
), for which the application rates were found to be particularly high. This was also reflected in their relative contribution (Figure 4
The highest impact on the climate and several other environmental categories per kg of food was found for ruminant meat, i.e., beef and lamb (Figure 3
), which is in line with earlier findings [7
]. This led to important contributions to the impacts of the average diet for all variables, but were especially pronounced for GHG emissions, cropland use and nitrogen application (Figure 4
). Pork, chicken, processed meat products and dairy products such as cheese also had high environmental impacts per kg (Figure 3
) and made a high contribution to all impacts (Figure 4
). The impacts of fish and seafood varied depending on fish species (Supplementary Material
), but the relative contribution to the overall impacts was generally low compared with that of other animal products (Figure 4
3.4. Study Limitations
The global boundaries, indicators and corresponding inventory data used to assess the environmental impacts of Swedish food consumption in this study are all associated with uncertainties and limitations and thus, there is potential for increasing the accuracy of the results in future research.
As for setting absolute global boundaries for the food system, as highlighted by the EAT-Lancet
authors, this is highly challenging since the drivers of Earth system processes are complex and interconnected. In addition, some of the EAT-Lancet
boundaries have been criticised for not relating to the original absolute threshold levels of the Planetary Boundaries, i.e., based on absolute biophysical limits for Earth systems within which humanity should operate. The boundaries for GHG emissions and nitrogen application are, instead, based on the unavoidable share of emissions and resources needed to feed the global population. Einarsson, McCrory and Persson [94
] pointed out that in order for the boundaries to be scientifically consistent, they should rely upon scientific evidence on the limits of the Earth systems, although this causes trade-offs between reaching environmental targets and maintaining current levels of prosperity.
As for calculating the environmental impacts from the Swedish diet for different indicators, these assessments are also associated with model and data uncertainties. For calculating cropland use, there is, in general, good data availability on yield levels through statistics databases (e.g., [3
]). Further, as the indicator focuses solely on one variable, i.e., crop productivity levels, calculations are straight-forward. For GHG emissions, on the other hand, important emissions arise in several process steps in the life cycle of various food products. In many of these steps, emissions are variable due to, e.g., climate conditions and soil characteristics. Furthermore, different methodological choices can be made to account for the emissions, which can substantially affect the results, e.g., when accounting for emissions from land use and land use change. Other limitations to assessment of GHG emissions include lack of detailed inventory data for countries outside Europe and lack of data on food groups such as fish and seafood [26
]. For example, the GHG emissions for meat on the Swedish market have been found to vary from approximately −40% to +100% [95
]. Uncertainties are always important to consider, and even more so when benchmarking against absolute boundaries. Establishing uncertainty ranges for the environmental impacts of the Swedish diet is, hence, an important topic for coming studies, but is associated with major difficulties due to data limitations, e.g., on variations in input data, that become increasingly important as impacts are reduced to fit within the boundaries.
With respect to nitrogen and phosphorus application, site-specific data from statistical databases or advisory services are primarily available for Sweden and other European countries (e.g., [30
]), while data for production countries outside Europe mainly are available through databases (e.g., the World Food LCA Database [33
]), peer-reviewed studies or LCA reports.
Regarding consumptive freshwater use, inventory data for the present study were primarily obtained from the WaterStat database [68
]. A limitation in the inventory data is that consumptive water use for crops does not necessarily represent the actual water consumed. Rather, it is based on modelling crop water requirements using inventory data on crop parameters and climate parameters such as temperature and precipitation [69
Concerning estimation of potential extinctions due to land occupation, there are several uncertainties, deriving from both general modelling and variables, and from data gaps and uncertainties in inventory data, in the methodology developed by Chaudhary and Brooks [70
]. There is potential to extend the modelling to include additional land use classes (e.g., by distinguishing between annual and permanent crops) and taxa (e.g., by including invertebrates) [70
]. For these indicators, data on uncertainties are largely missing; a gap that needs to be filled in future research. Furthermore, the choice of time horizon for allocation of overall potential species loss had to be chosen arbitrarily, which had large impacts on the results for biodiversity loss. For example, allocating all of the impacts to the same year would, naturally, lead to a 100 times larger impact, which would be 600-fold the EAT-Lancet
boundary. Using 20 years would show impacts 30 times the boundary while allocating the species loss over 500 years would cause impacts 1.2-fold the boundary.
Another limitation in the present study relates to the food supply data, which were obtained from the statistical database of the Swedish Board of Agriculture [18
]. For some of the product groups, e.g., vegetable fats, sauces, fish and seafood, detailed statistics are lacking and assumptions have to be made based on, e.g., food surveys and reports [87