Technical rationale: Nearly all Parties indicated in their fourth national reports that pollution was posing a threat to biodiversity. Nutrient loading, primarily of nitrogen and phosphorus, is a major and increasing cause of biodiversity loss and ecosystem dysfunction, particularly in wetland, coastal and dryland areas, including through eutrophication and the creation of hypoxic “dead zones” associated with severe losses of valuable ecosystem services.²⁶,²⁷,²⁸,²⁹ Humans have already more than doubled the amount of “reactive nitrogen” in the biosphere, and business-as-usual trends would suggest a further increase of the same magnitude by 2050. This target is consistent with, and complementary to, work under the Rotterdam and Stockholm Conventions and the target established in the Johannesburg Plan of Implementation (para. 23) to achieve, by 2020, a situation where chemicals are used and produced in ways that lead to the minimization of significant adverse effects on human health and the environment.

Implementation: The better control of sources of pollution, including efficiency in fertilizer use and the better management of animal wastes, coupled with the use of wetlands as natural filtration plants where appropriate, can be used to bring nutrient levels below those that are critical for ecosystem functioning, while also allowing for increased fertilizer use in areas where it is necessary to meet soil fertility and food security needs. The EU has successfully promoted regulations to this end, and the evidence suggests that similar approaches are feasible in other developed and emerging economies.³⁰,³¹ Similarly, the development of national water quality guidelines could help to limit pollution and excess nutrients from entering freshwater and marine ecosystems. This target is relevant to several programmes of work but, in particular, to those dealing with inland water biodiversity and marine and coastal biodiversity and the Convention’s work on impact assessment.

Indicators and baseline information: Relevant indicators include nitrogen deposition and water quality in freshwater ecosystems. Other possible indicators could be the Ecological Footprint and related concepts, total nutrient use, nutrient loading in freshwater and marine environments, and the incidence of hypoxic zones and algal blooms. Data which could provide baseline information already exists for several of these indicators, including the incidence of marine dead zones (an example of human-induced ecosystem failure) and the global aerial deposition of reactive nitrogen.


²⁶Diaz, R J, & Rosenberg, R (2008). Spreading Dead Zones and Consequences for Marine Ecosystems. Science, 321(5891), 926-929. doi: 10.1126/science.1156401.
²⁷Phoenix, G K, et al. (2006). Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts. Global Change Biology, 12(3), 470-476.
²⁸Hicks, K, et al. (2009). Global Assessment of Nitrogen Deposition Effects on Terrestrial Plant Diversity: a synthesis.
²⁹Galloway, J N, et al. (2008). Transformation of the Nitrogen Cycle: Recent Trends, Questions, and Potential Solutions. Science, 320(5878), 889-892.
³⁰Bobbink, R, (in press) Global Assessment of Nitrogen Deposition Effects on Terrestrial Plant Diversity: a synthesis. Ecological Applications.
³¹Ju, X, et al. (2009). Reducing environmental risk by improving N management in intensive Chinese agricultural systems. Proceedings of the National Academy of Sciences of the United States of America, 106(9), 3041-3046.