In 2022, United Nations member countries agreed to reduce the pesticide risk to biodiversity by at least half by the end of the decade. However, a new study shows that the increasing toxicity of pesticides could undermine this commitment.
A group of researchers from the Kaiserslautern-Landau University in Germany analyzed data on pesticide use worldwide and related the amount of each active ingredient used to its toxicity. By calculating the toxicity of pesticides used annually in the countries’ agriculture, the team developed a method to estimate the potential global impact of agricultural pesticides on biodiversity.
“This gives us a completely new perspective on the potential risks to the environment and biodiversity represented by the use of pesticides,” explains Ralf Schulz, the study’s principal co-author, published in the journal Science.
The researchers analyzed the use of 625 pesticides between 2013 and 2019 worldwide and concluded that, during the period studied, these products became “significantly” more toxic.
“This is due, in part, to the increase in the amount of pesticides applied, as arable land is expanding or existing land is being cultivated more intensively, but also due to the rising toxicity of the substances applied, especially insecticides,” explains Schulz.
The increases in toxicity, the researchers say, affect especially terrestrial insects, soil organisms and fish. However, higher risks were also recorded for aquatic invertebrates, pollinating insects, and terrestrial plants. Only for aquatic plants and terrestrial vertebrates was a reduction in toxicity found.
All groups of pesticides – herbicides, insecticides and fungicides – contributed to the overall increase in toxicity of these products, the scientists report, who identified about 20 active ingredients in pesticides that have a significant impact on different groups of animals and plants.
Therefore, they suggest that these ingredients be replaced with less toxic ones to enable better protection of biodiversity.
Brazil, China, the United States of America and India were the countries that contributed most to the global trend of increasing pesticide toxicity between 2013 and 2019. Even for the countries that contributed least to this increase, the researchers say that the expansion and intensification of agriculture worldwide could further exacerbate the impacts of pesticides on biodiversity and jeopardize the Kunming-Montreal Global Biodiversity Framework.
Around 80% of globally used pesticides in that period were applied to fruit and vegetable crops, maize, soy, cereals, and rice.
The authors of this study say that, although the study’s data stop in 2019, all indications are that pesticide pollution has continued to rise and continues to increase today.
Without immediate action, Chile will be the only country in the world to achieve the 2030 target to which the signatory states of the Kunming-Montreal Agreement committed. Although it seems increasingly distant, it may still be possible to reach that target, but for that to happen, in addition to replacing active ingredients with less toxic ones, more conventional agricultural areas must be converted to organic production, “which would have even more positive effects on the protection of global biodiversity,” says Jakob Wolfram, the first author of the article.
