Ecosystems are impacted by air pollution, particularly sulphur and nitrogen emissions, and ground-level ozone as it affects their ability to function and grow. Emissions of both sulphur dioxide and nitrogen oxides deposit in water, on vegetation and on soils as “acid rain”, thereby increasing their acidity with adverse effects on flora and fauna. Ultimately, acidification affects the ability of ecosystems to provide “ecosystem services”, such as for example nutrient cycling and carbon cycling, but also water provision, on which the planet and human life is dependent.
Increased ground-level ozone also causes damage to cell membranes on plants inhibiting key processes required for their growth and development. The loss of plant cover affects us all. Trees and other vegetation absorb pollutants such as excessive nitrogen dioxide, ozone and particulate matter, through their leaves and needles and thereby help to improve air quality. Less plant cover thus means less filtering capacity to clean our air.
Eutrophication, the process of accumulation of nutrients, including nitrogen, in water bodies, often results from air pollution. Nutrient overloads in aquatic ecosystems can cause algae blooms and ultimately a loss of oxygen, and of life. As ecosystems are impacted, so is the biological diversity.
Even worse, ultimately human populations are also affected. Harmful concentrations of pollutants may directly enter our drinking water, notably through ground water seepage. Equally, water quality may be deteriorated as air pollution negatively affects vegetation which helps to naturally filter our water systems. Affected vegetation also has negative consequences on another important ecosystem service: that of capturing carbon and thereby reducing the impacts of climate change.
What we do
The Convention sets targets for various air pollutants, and thus assists countries in mitigating effects on ecosystems and biodiversity. A number of bodies under the Convention monitor and investigate the effects of key air pollutants on different parts of ecosystems. Overall, this work will help countries in achieving a number of targets under various Sustainable Development Goals, such as those on life on land (SDG 15), life below water (SDG 14), and responsible consumption and production (SDG 12).
More concretely, the International Cooperative Programme on Assessment and Monitoring of the Effects of Air Pollution on Rivers and Lakes assesses the degree and geographical extent of acidification of surface waters. The objective of the International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems is to monitor the state of ecosystems, their changes and effects of air pollutants and climate change from a long-term perspective, and to develop and validate models for the simulation of ecosystem responses.
The International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests provides a periodic overview on the condition of forest ecosystems in terms of health, productivity, diversity and nutrition. The International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops is assessing the impacts of air pollutants, particularly ground-level ozone, on semi-natural vegetation and crops. In addition, the Task Force on Reactive Nitrogen develops technical and scientific information and encourages coordination of air pollution policies on nitrogen in the context of the nitrogen cycle.