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Indicators proposed for nutrient and pesticide pollution in the current text of the Convention on Biological Diversity’s post-2020 Global Biodiversity Framework (GBF) are inadequate for tracking progress and informing policy. We highlight a set of more relevant pollution indicators that would strengthen the monitoring framework of the GBF and discuss conditions for their successful implementation.

Pollution is ranked as one of the five main drivers of biodiversity loss by the Intergovernmental Science-Policy Platform On Biodiversity And Ecosystem Services (IPBES) global assessment1. Pollution by pesticides and nutrients, especially nitrogen and phosphorus, are of particular concern. At COP15 in 2022, the Convention on Biological Diversity (CBD)’s Global Biodiversity Framework (GBF) adopted ambitious global targets to at least halve excess nutrients lost to the environment and overall pesticide risk by 2030 (ref. 2). Previous targets set by governments at COP10 of the Convention on Biological Diversity in 2010 sought to “bring pollution down to levels that are not detrimental to ecosystem function and biodiversity”. There was little progress in the ensuing decade, so ensuring that targets are met this time around will require considerably stronger commitments from all actors.

Here, we suggest a set of indicators for nutrient and pesticide pollution that would be better suited for monitoring progress and informing policy than those currently proposed in the monitoring framework of the GBF3,4. We also argue that there cannot be a one-size-fits-all approach to the adoption of quantitative objectives, because global targets to reduce pollution need to be explicitly adapted to national and geographical contexts. Finally, jointly addressing pesticide and nutrient pollution will require a systemic approach, tackling drivers on an agri-food system level as well as non-agricultural sources.

Suitable indicators to define and monitor reduction targets In a science brief provided to the ‘Open-ended Working Group on the Post-2020 Global Biodiversity Framework’ in June 2022, we provided scientific background to support negotiations of the GBF pollution target (target 7)5. In it, we argued that objectives for reducing nutrient pollution should focus on reducing nitrogen and phosphorus lost to the environment from all sources, and not solely from agriculture. This is because anthropogenic losses of nitrogen and phosphorus to the environment are known to degrade biodiversity, regardless of their source. A focus on agricultural nitrogen and phosphorus input use alone would be too narrow to capture this effect fully. We also argued that objectives for reducing pesticide pollution should focus on reducing risk rather than reducing total applied quantities. This is because certain groups of species are at high risk from very toxic pesticides, even when used in low quantities.

The wording of target 7 of the GBF on pollution reflects these recommendations and is solidly founded in science. However, the high-priority indicators in the current version of the monitoring framework for nutrient pollution (the index of coastal eutrophication potential) and pesticide pollution (pesticide environment concentration) are not well matched to capture the overall scope of the targets, track progress and inform policy3,4 (Box 1, Fig. 1).

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