The human population is continuing to grow. They consume more and more food. Vegetables, fruit and other foods are transported long distances between countries by ship and truck and contribute to a growing impact on the climate.

 At the same time yields are stagnating, and in some areas the arable quality of the soil is drastically impoverished due to inappropriate agricultural practices; consequently marginal production areas and nature conservation areas are subsumed into agricultural production at the expense of biodiversity. This is tipping the balance of sustainability in the wrong direction.

When the talk turns to securing food for all in a sustainable manner, thus minimising the impact on the planet, then it is a complex issue that scientists have to deal with.

One of those researching the issues of sustainable food production is John E. Hermansen, section manager at the Department of Agroecology at Aarhus University. The combination of population growth and increased per capita consumption of animal products does in his opinion put a lot of pressure on the environment:

- We see that on a global level meat consumption is rising fast. Over the past 40 years, pig production has tripled and chicken production has increased sevenfold, and total meat consumption is estimated to increase by another 40 percent over the next 20 years. The increased consumption will primarily take place in the countries outside Europe and North America due to their increased purchasing power. Meat requires feed for the animals and feed production requires large areas under agricultural cultivation. It piles on the pressure on terrestrial resources. So there is good reason to innovate, both in terms of meat consumption and in the way production is carried out. In the western world there is also evidence that reducing meat consumption is good from a nutritional point of view.

Beef and chicken in climate battle

Several scientists have argued that beef should be dropped in favour of poultry because the climate impact of beef production is relatively high due to the large emissions of harmful greenhouse gases such as methane and CO₂ from cattle.

But the equation is not that straightforward.

 - The choice between beef and chicken is a very complex problem, because part of the beef production is based on grassland in no direct competition with crops for human consumption, while chickens to a far greater extent receive grain and soy products that could be used in food production.

John E. Hermansen adds as an aside that there are low-hanging fruits to be picked by concentrating efforts in countries with very large beef productions such as Brazil, where the production form can be optimised.

- The beef cattle today in Brazil grow very slowly and are quite old when they reach slaughter weight. This is damaging the climate, because cattle emit large amounts of harmful methane. There is a large potential in intensifying the production via management improvements. This will have a positive impact on the climate, he observes.

Three threats to sustainable food production

In his research John E. Hermansen is particularly concerned with the carbon footprint of food production, but he draws a picture of three threats that compel a discussion of a more sustainable food production in the future.

- There are three main challenges: Our increasing food production contributes to a huge loss of biodiversity which is far beyond what is acceptable. There is talk about an extinction of species that is 1,000 times higher than normal as a result of our current forms of production. Moreover, we see a large input of mineral fertilizers, which also threatens the balance of the ecosystem, and finally there is global warming, providing humanity with a major challenge that we have already felt the consequences of, warns John E. Hermansen.

He points out that food production is responsible for between a third and a half of the damage that nature is currently suffering. Therefore, it is vital to keep thinking sustainably at all stages of the production chain and to optimise the parts that are currently less efficient.

He maintains a hope that the future will also be able to provide humanity with sufficient sustainable food. Small technological breakthroughs continue to take place that improve the basis for sustainable food production. Cultured meat may here be one of the solutions.

- Cultured meat is definitely an interesting area that can diminish the challenges. This area will be interesting to follow in the future, according to John E. Hermansen.

But he is particularly concerned with helping to address the current problem of demand for arable land, for growing food in the fields best suited for this purpose, and to then incorporate and utilise less productive areas for livestock fodder production.

- Up to a quarter of the available land in the world is grassland or other extensive systems for which yields can be very low. There is a need to develop production methods that significantly raise the yields on these areas. At the same time it would be appropriate to optimise the use of grassland, for example for the production of proteins for production animals. To this end we are starting a huge research effort into biomass, which I see as the big eye-opener in the future. There is a huge potential to grow much more biomass – for energy, food and fodder. It will have a major impact on sustainability because it eases the pressure on soil resources, and that means that we will not need to incorporate as many of the existing natural areas in the production. It is also relevant to look at new methods for the production of feed proteins such as microalgae that in commercial productions only require a very small area. All these initiatives mean that the cultivated land can be better used to make food for humans rather than being mostly used to feed the animals, says John E. Hermansen.

Organic or conventional farming

Sustainability is most often linked to the organic way of farming rather than the conventional one, but according to John E. Hermansen there is no clear winner in terms of carbon footprint. While conventional operations produce high yields but require pesticides, use monocultures and give less biodiversity, the reverse is true for organic farming.

- We have conducted studies that show that for organic and conventional production methods, the carbon footprint is roughly the same, is his conclusion.

In addition to technological advances that continually improve yields and reduce the overall carbon footprint, he also identifies agroforestry as a form of production that is worth focusing on in relation to sustainability.

- Agroforestry is a production method where the combination of trees with other crops and/or livestock means a better utilisation of the solar radiation for the production of biomass on an annual basis while reducing the environmental impact. Although it initially sounds difficult to implement, it will be one of the areas where new intelligent technology can make a difference, is his assessment.

Climate-friendly Christmas lunch

At our latitudes the focus has in recent years turned to food waste. Initiatives John E. Hermansen strongly welcomes because they reduce food consumption generally. An increased focus on high-quality foods will have the same effect, he believes.

John E. Hermansen also has some advice for those who would like to do their bit for the climate at the forthcoming Christmas parties and Christmas dinners:

- We can help our natural environment by doing without the rice pudding since the cultivation of rice actually produces large emissions of methane, which is a very harmful greenhouse gas, he says with a twinkle in his eye.

Further information: Section manager John E. Hermansen, Department of Agroecology, telephone: +45 87158017 e-mail: john.hermansen@agrsci.dk