Enlarge image
Fried insects at a market in Thailand
Photo: Leisa Tyler/LightRocket via Getty Images
Conventional agriculture takes up large areas, sometimes uses scarce water, but above all the production of food is responsible for about a third of greenhouse gas emissions worldwide.
In short: the still widespread way of producing food has dramatic consequences for the environment.
The high consumption of meat in particular contributes to the poor eco-balance.
Finnish researchers show in the journal »Nature Food« that there is another way.
If, argues the team led by Rachel Mazac from the University of Helsinki, the conventional animal-based diet in Europe were replaced by an ecologically optimized diet, both land and water consumption as well as greenhouse gas emissions could be reduced by more than 80 percent – at least in theory based on models.
The team compared the environmental impacts of three ecologically optimized diets with the current European diet:
an optimized diet containing animal products (“omnivore nutrition”),
an optimized vegan diet
a diet based on so-called novel foods (NFF, Novel/Future Food).
In doing so, they used official data from the European Food Safety Authority EFSA, for example, and made sure that the nutrient requirements were met for each variant.
The third category seemed particularly interesting to them.
This is where foods fall that are produced using new production techniques – such as meat, eggs and milk from the laboratory or foods based on microalgae, fungi, bacteria or insects such as mealworms, grasshoppers and crickets.
This diet not only protects the climate and environment, but is also nutritionally sensible, writes the team around Mazac.
"Compared to currently available plant-based protein-rich options like legumes and grains, NFFs can contain a more complete spectrum of essential nutrients like protein, calcium, vitamin B12 and omega-3 polyunsaturated fatty acids."
Each diet was in turn put together in three scenarios in such a way that the consequences either for
the land use,
water consumption or
the greenhouse gas balance
have been minimized.
For example, in the omnivorous diet in the water-conserving variant, eggs, animal fats and sugar were excluded, but not in the other scenarios optimized for land use and climate.
Meat consumption crucial
Compared to conventional diets, an ecologically optimized omnivore or purely vegan diet tended to reduce the impact on land, water and climate in a very similar way – by 81 to 84 percent each.
According to the team, the reduction or even the elimination of meat consumption alone accounts for about 60 percent of the positive balance of ecologically optimized forms of nutrition.
However, an NFF diet reduced consumption even more significantly, namely by 83 to 87 percent.
The team explains these high values compared to previous studies, among other things, by considering a large number of new products.
»Greenhouse gas emissions from novel foods depend significantly on the availability of low-carbon energy sources«
Florian Humpenöder, Potsdam Institute for Climate Impact Research
"Especially for novel foods that are still in development - such as milk from cell cultures - there are greater uncertainties with regard to their environmental impact," comments researcher Florian Humpenöder from the Potsdam Institute for Climate Impact Research, who was not involved in the study.
A key factor is energy consumption.
»Instead of feeding animals, which then provide milk and meat, more energy is required in the production process in cellular agriculture, for example to heat bioreactors.
The greenhouse gas emissions of novel foods therefore depend to a large extent on the availability of low-carbon energy sources,” says Humpenöder.
(The SPIEGEL climate report - the latest developments, research results and background information on the climate crisis as a newsletter: every week directly in your e-mail inbox.
Register now
.)
However, there is another crucial point: Are consumers even willing to change their diet so radically?
It remains to be seen whether all people in Europe will really get a large part of their nutrients from insect meal, algae or in vitro cultures in the future, says Matin Qaim, Director at the Center for Development Research (ZEF) at the University of Bonn, who also did not take part in the study was involved.
»The results show what could theoretically be possible and not what can realistically be expected in the near future.
That is why the calculated savings in environmental impacts are also greater here than in previous studies.«
In view of the cross-cultural importance of animal-based foods, it may be difficult to change the diet on a broad basis, admits the team led by study leader Mazac.
In Europe in particular, people have reservations about foods that are unfamiliar to them or that appear unnatural.
It is therefore necessary to educate people about the benefits for their own health, the environment and animal welfare.
Ultimately, however, taste and price also played an important role.
In a comment on Nature, Asaf Tzachor from the University of Cambridge praised the study.
It answers the question of whether a switch to sustainable nutrition would be feasible and how much the environment would benefit from it, writes the sustainability expert.
The study thus brings such a transition “a decisive step closer”.
chs/dpa
