A bread and its ecological footprint

Researchers calculate the environmental balance of baked goods

Which ecological balance does this wholegrain bread have? And what does it matter? Researchers have determined just that. © Anna Liebiedieva / thinkstock
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LCA calculated: Even the production of a single loaf of wholegrain bread leaves a clear mark on our planet. This is the result of researchers who have determined the ecological footprint of baked goods - from grain cultivation to baking. Above all, the cultivation of the grain beats negatively. A big problem here: the massive use of nitrate-containing fertilizers.

Be it air travel, buying clothes or enjoyable food: Almost everything we do leaves an ecological footprint. Food production plays an important role here. After all, around one third of all greenhouse gas emissions worldwide go back to the production of food.

Basically, that's nothing new. For this reason, experts have been pleading for a longer time to think about the environment while eating. For example, those who shop regionally or seasonally, or who eat vegetarian food, do nature a favor. However, harmful effects on the production of food can not be completely avoided. In addition, many consumers often do not even know which traces a particular product has left on its way to the supermarket shelves in the environment.

From grain cultivation to baking

"Knowing which steps in the production and how much impact on the environment, but is necessary. Only then can farmers, food industry and consumers act responsibly and try to reduce these influences in the future, "write scientists around Liam Goucher from the University of Sheffield.

The researchers have set a good example and have taken the time to look in detail at the environmental footprint of a product that lands on our plates every day. They wanted to know: Which life cycle assessment actually has the production of a single loaf of bread - from grain cultivation to the baking process? display

Wheat cultivation accounts for a large part of the cological footprint of a bread. Sandra H / pixabay

Emissions for 800 grams of full grain

For their analysis, Goucher and his colleagues considered a 800 gram whole grain bread made in the UK. They collected environmental data for each aspect of the manufacturing process and applied this information to six categories - including global warming potential, drinking water pollution, and production of harmful toxins.

For example, they found out that the global warming potential of the entire production chain corresponds to 0.589 kilograms of CO2 equivalents. By comparison, according to the environmental organization WWF, a dairy cow produces just under 2.35 tonnes of CO2 equivalent per year through its methane emissions. However, considering that the researchers' calculations only refer to a single small piece of bread, and that most of us consume far more bread than beef, the emissions are by no means insignificant.

Problem fertilizer

The lion's share of the ecological footprint goes back to the cultivation of the cereal used. According to the analysis, this step is responsible for more than half of the harmful environmental impacts - all categories considered together. Above all, the massive use of ammonium and nitrate-containing fertilizers has a negative impact here. These substances pollute the groundwater and, through natural processes, enter the atmosphere as climate-friendly nitrous oxide, for example.

The fertilization of fields with ammonium- and nitrate-containing fertilizers accounts for more than half of the negative environmental consequences. pixwel1 / pixabay

At this point, according to the researchers, it would be necessary to start in order to improve the environmental balance of the bread. The problem, however, is that many farmers can only produce rich crops and produce economically if they work hard. The use of cheap, often subsidized fertilizers is therefore on the agenda.

A change in thinking is not in sight: "The focus of the system is just to earn money - and not to produce as sustainable as possible, " write Goucher and his colleagues. The dependence on fertilizer remains one of the biggest, most unresolved challenges of the 21st century.

Everyone has to join in

However, the researchers emphasize that even if some participants bear more responsibility for the cological footprint of bread than others, only a holistic approach is effective in the long term. Therefore, in order to achieve sustainable improvements, all actors would have to participate - from the fertilizer producer, through the farmer, the miller, the bakery, to the retailer and the consumer. (Nature Plants, 2017; doi: 10.1038 / nplants.2017.12)

(Nature, 28.02.2017 - DAL)