How can humanity feed the growing world population while protecting the climate and respecting planetary boundaries? Advocates of the “degrowth” theory believe that this will only work if the world says goodbye to the model of the ever-growing economy and people in richer countries build a good life with less consumption, production and money overall.

According to degrowth advocates, such a revolution would help reduce climate-damaging emissions and use the remaining farmland on earth to provide humanity with a sustainable supply.

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A team led by scientists Benjamin Bodirsky and David Chen from the Potsdam Institute for Climate Impact Research tested these assumptions for the first time in a study for the global food system. The results in the specialist magazine “Nature Food” show that less money for people in rich countries and more money for people in poor countries would hardly lead to more climate protection in the current food system. The reason for this is that higher incomes in poor countries promote climate-damaging diets such as more meat and cheese consumption.

In one of the six scenarios examined, however, the climate-damaging greenhouse gas emissions fell significantly: if humanity wasted less food and consumed less animal products such as meat and cheese by 2030 in order not to exceed planetary boundaries. In another scenario, the CO₂ emissions in the global food system fell, even if their emissions cost something in accordance with the 1.5-degree climate target.

Such a CO₂ price would mean that flour, tomatoes or sausage, for example, would become more expensive or remain cheap – depending on how much climate-damaging CO₂ their production causes. Such a measure would factor in the cost of climate pollution and encourage people to eat or produce their food in a more climate-friendly way.

As expected, a combination of several measures brought the best results in climate protection: less meat and milk, less food waste, a CO₂ price and that poorer countries are supported by richer countries with international transfer payments.

In this way, in the scenario, emissions from agriculture would shrink from 14.4 gigatons of CO₂ emissions in 2020 to 1.18 gigatons of CO₂ emissions in 2050. According to the researchers, in the remaining 50 years there would then be enough land to reforest and allow forests to grow or other ecosystems to thrive.

The natural climate protectors would then bind CO₂ from the atmosphere and offset unavoidable greenhouse gases such as nitrous oxide from fertilizers and methane from livestock elsewhere. By 2100, the global food system would then be climate-neutral, meaning there would be zero emissions that are harmful to the climate.

Of the climate protection measures mentioned, the CO₂ price is well known in Germany: a national CO₂ price already makes fossil fuels such as petrol and diesel in the transport sector and heating oil and natural gas in the building sector more expensive. The European CO₂ price takes effect in the energy sector and makes climate-damaging coal-fired power plants in particular unprofitable, making wind and solar systems increasingly competitive. However, agriculture in Germany has so far been exempt from CO₂ pricing.

The research work is one of the rather rare analyzes that use calculations to sound out “degrowth” hypotheses on climate protection and planetary boundaries – in this case the global food system. In recent years, economic debates about the need for “degrowth” have gained momentum – i.e. the question of whether the economy in richer countries in particular has to shrink and prosperity has to be achieved in a different way than through more consumption and production, so that mankind does not lose the basis of its existence destroyed.