The environmental effects of agriculture and food are constantly hotly debated. But the most widely used method of analysis often tends to overlook vital factors, such as biodiversity, soil quality, the huge impact of pesticides and changes in society. It seems absurd but it is exactly like that: an important research on organic agriculture carried out by three researchers of the scientific journal Nature Sustainability explains it to us .

The common method currently used

The so-called Life Cycle Assessment (LCA) is used to evaluate the environmental impacts of agriculture and food . Studies using this method sometimes claim that organic farming is even worse for the climate because it has lower yields and therefore uses more land to compensate for a lower productivity level. As an example, a recent study published in Nature Communications to have exposed this hypothesis has been reported by many media, including the BBC and other major international newspapers.

The LCA method simplifies the importance of organic products too much

But according to three researchers from France, Denmark and Sweden, who present an analysis of many LCA studies in the journal Nature Sustainability, the LCA parameters are overly simplistic and do not underline some important benefits of organic agriculture .

"We are concerned that the LCA criteria provide too narrow a picture: the real risk is that of making wrong decisions both from a political and social point of view. When comparing organic and intensive agriculture, there are more effects that the current approach totally ignores, "says Hayo van der Werf of the French National Agricultural Research Institute.

Biodiversity , for example, is vital for the health and resilience of ecosystems. But globally, it is decreasing: intensive agriculture has proven to be one of the main drivers of negative trends such as the decline of insects and birds. Agriculture occupies more than a third of the global land surface, so all the links between biodiversity losses and agriculture are extremely important.

"Our analysis shows that current LCA studies rarely take biodiversity into account and, as a result, they are usually totally lacking in enhancing the wider benefit of organic farming, " says Marie Trydeman Knudsen of the University of Aarhus, Denmark.

"Previous studies have already shown that organic fields support about 30% higher biodiversity levels than conventional fields."

Pesticides and land use

The use of pesticides is another factor to consider. Between 1990 and 2015, the use of pesticides worldwide increased by 73%. Pesticide residues in soil, water and food can be harmful to human health, terrestrial and aquatic ecosystems and cause biodiversity losses. Organic agriculture, meanwhile, precludes the use of synthetic pesticides. But few LCA studies explain these effects.

Soil degradation and its low quality, resulting from unsustainable soil management, also represent a problem, once again, something that is rarely measured by the LCA parameters. The benefits of organic farming practices such as varied crop rotation and the use of organic fertilizers are often overlooked in LCA studies.

Very generally the LCA protocol assesses the environmental impacts per kilogram of product. This favors intensive systems that can have a lower impact per kilogram, while having a greater impact per hectare of land .

"The LCA system simply examines the overall yields. Of course, from such a perspective, it is true that intensive cultivation methods are actually more effective. But this is only a very small part of the entire history of the agricultural ecosystem. A diversified landscape with smaller fields, hedges and a variety of crops offer other benefits, such as increased biodiversity, "says Christel Cederberg of Chalmers University of Technology in Sweden.

The LCA results-centric approach also fails to capture the subtleties of smaller, more diverse systems that depend more on ecological processes and adapt to the characteristics of the soil, climate and local ecosystems. The LCA approach needs to be reformed as soon as possible.

"We often observe the effects at the global food chain level, but we have to be much better at considering the environmental effects at the local level," says Marie Trydeman Knudsen. The researchers noted in their study that efforts are being made in this area, but much more progress is needed.

Indirect effects

A further and particular weakness occurs when hypothetical "indirect effects" are included, such as the assumption that the lower yields of organic agriculture lead to an increase in carbon dioxide emissions, since more land is needed. For example, another important study - conducted by a researcher also from Chalmers University of Technology - suggested that organic farming was worse for the climate, because the requirement of more land indirectly leads to a smaller forest area. But it is very difficult to give evidence of these indirect effects.

"Take for example the growing demand for organic meat. Traditional LCA studies could simply assume that overall meat consumption will remain the same, and therefore more land will be needed. But consumers who are motivated to buy organic meat for Environmental and ethical reasons tend to buy even less animal-based products in the first place. But hardly any studies of this type of consumer behavior exist, so today it is very difficult to explain these types of social changes, "says Hayo van der Werf.

"The current LCA methodology and practice is not complete enough to evaluate agroecological systems such as organic agriculture. Therefore, it is very important that it is improved and integrated with other environmental assessment tools in order to obtain a more balanced and corresponding to reality "finally underlines Christel Cederberg.

The quality of what we eat and what we breathe certainly starts from these notions of actuality. Anyone should make them their own and share them with their loved ones, to help our communities grow free of superstitions and fake news.