Livestock on leftovers

Greenhouse gas and nitrogen emissions from agriculture in the Nordic countries could be reduced by up to 80 per cent with a diet of purely organic produce from an almost self-sufficient food system.

Most of the emissions from agriculture are linked to animal husbandry. There are several possible strategies for reducing these emissions.

The strategy mostly favoured by agricultural unions and the food industry is to make present production more efficient, so-called sustainable intensification. But this path has its limitations. If the consumption of animal products keeps growing, emissions will still increase even if emissions per kilogram of product are reduced. In the other corner, we have those who promote a totally vegan society. “No livestock – no emissions” makes sense. But this overlooks the positive biodiversity aspects of grazing animals and the resource efficiency of letting animals forage on feed that cannot be used for human consumption.

A third strategy, “livestock on leftovers”, is explored in a study by the Swedish University of Agricultural Sciences, commissioned by AirClim, which focuses on four Nordic countries and will be published later this spring. Animal production is limited to feeding on resources that are not in direct competition with human food production. Ruminants are allowed to graze on semi-natural pastures and other animals are given by-products from food production.
Other key principles of the study are that food should be produced in an organic farming system and countries should be self-sufficient in the food products that can be produced locally, but are able to import other food products such as tropical fruits, nuts, coffee and tea. Agriculture should be self-sufficient in energy, but should not provide energy for other parts of society.

These principles have then been interpreted and modelled in three different scenarios:

• The first is a Sufficiency scenario, developed from a strict interpretation of the principles. The number of cattle and sheep was limited to the minimum needed to graze available semi-natural pastures in each country. By-products were used to feed poultry, pigs and aquaculture fish, and provide supplementary feed for cattle and sheep. Only grass and by-products were allowed in the livestock diets and no additional feed was grown, apart from ley.
• The second is an Efficiency scenario, developed to improve the use of the available resources (grass and by-products). Cattle and sheep were allowed to graze on pastures on arable land, and more grass was used as winter feed in order to make use of all ley grown through crop rotation. In order to use a larger fraction of the by-products, up to 40 per cent of grown feed was included in the food rations.
• The third is a Capacity scenario, developed to explore the effects of using all available land. After land for growing plant-based food had been allocated, the remaining land was used to grow feed for animals.

To ensure a healthy diet with high acceptability to the Nordic population, the scenario diets were based on the Swedish nutrient recommendations translated into food items (SNÖ). This is a model diet designed to be similar to the present Swedish diet while also fulfilling the Nordic Nutrient Recommendations.

The scenarios were set in 2030 and applied to the cases of Denmark, Finland, Norway and Sweden using national statistics on available arable land and semi-natural pastures, crop yields and nutrient leaching.

Drained peatlands were deducted from the available arable area since they cause considerable methane emissions when cultivated. In Denmark, there is a shortage of natural land, so 15 per cent of the arable area was deducted to increase the share of wild nature.

In addition to the national cases, a common “Nordic” case was modelled, in which all four countries were treated as an entity. The results presented here focus primarily on that case. The projected total population of all four countries by 2030 is 28.4 million inhabitants.

The results show quite extensive changes in comparison to the current diet (box). Meat consumption is reduced by 89 per cent in the Sufficiency scenario, by 79 per cent in the Efficiency scenario and by 52 per cent in the Capacity scenario, and replaced by legumes. It is worth noting that some of the changes are due to the fact that the new diets follow health recommendations, which means an increase in vegetables and fruits.

The changes in land use differ between the countries; in general land use will be more diversified than today (figure 1). In the first two scenarios there is excess land after providing food for the local population. This land could be used for different purposes, e.g. growing biofuels, food for export, providing a buffer for population growth or turned into wild nature. In the Sufficiency scenario the excess land could potentially support another 13 million people with the Sufficiency diet. For the Efficiency scenario the corresponding figure is 11 million people.

Figure 1. Land-use for the different scennarios in per cent of current utilized agricultural area.

Livestock numbers are significantly reduced. In the Sufficiency scenario the number of cattle and sheep is around 30 per cent of present numbers, while poultry are reduced to 16 per cent and pigs to 6 per cent. The Efficiency scenario allows for slightly higher numbers; cattle and sheep are reduced to 44 per cent, poultry to 54 per cent and pigs to 16 per cent compared to today. The Capacity scenario has the highest numbers of livestock but still only allows half of the number of cattle and sheep, 57 per cent of the poultry and 68 per cent of the pigs.

There is no specialised beef production in any of the scenarios. Instead a multipurpose breed is used for both dairy and beef. This gives lower milk yields than the most common breeds in present dairy farming, but on the other hand it can be sustained on a higher proportion of roughage.

Poultry farming under these scenarios is also quite different from today. Instead of having totally separate production systems for eggs and poultry meat, a dual-purpose breed was used, with cockerels reared for meat. The scenarios limited egg production to 12 kg per capita per year, or 40 per cent more than in the SNÖ diet. However it would be possible to replace some of the pig farming in the scenarios with broiler chicken production, without extensive changes in the rest of the outcome.

Ammonia emissions are reduced by 75 per cent in the Sufficiency scenario, 66 per cent in the Efficiency scenario and by 50 per cent in the Capacity scenario, compared to present emissions. (figure 2) However, in the first two scenarios there is excess agricultural land, and if this was used to produce food for export, emissions would go up, but probably no higher than in the capacity scenario.

Figure 2. Emissions from agriculture for the different scenarios in per cent of current emissions.

The effect is even greater for greenhouse gases. The global warming potential per capita for the scenario diets (including emissions from imported food) are somewhere between 0.3 and 0.4 tonnes CO₂ eq/year. For comparison, the carbon footprint of food consumption in Sweden today is in the order of 2 tonnes CO₂ eq/year.

Nitrous oxide emissions are reduced by 83 per cent in the first two scenarios and by 75 per cent in the Capacity scenario. Methane emissions are reduced by 80 per cent in the Sufficiency scenario, 70 per cent in the Efficiency scenario and 66 per cent in the Capacity scenario.

Not included in these calculations is soil carbon. The reason for this is the huge uncertainties in terms of the data for this parameter so far. It is however possible to discuss the factors that influence it. Since the total area of ley will decrease compared to the present situation and the level of production will also decrease, sequestration will probably be reduced. This will be partially offset by the fact that organic crops have larger root systems than conventional crops. The inclusion of practices such as winter crops and catch crop production could also contribute positively to carbon sequestration.

Kajsa Pira

The report “Future Nordic Diets” will be published later this spring.