A new report on the effectiveness of international cooperation on cleaner air in the framework of the UNECE Convention on Long-range Transboundary Air Pollution (Air Convention) shows that while emission reductions have been achieved, countries in the Pan-European region and North America are set to suffer long-term damage from air pollution to human health, ecosystems and crop yields, also exacerbating climate change. To avoid this, the report, prepared over the last 3 years by leading scientists and policymakers in the region, calls for further targeted emission reduction measures across sectors including agriculture, energy, transport, and shipping, and wide-ranging societal changes in areas such as diet and heating.
The report analyses the sufficiency and effectiveness of the amended Protocol to Abate Acidification, Eutrophication and Ground-Level Ozone (Gothenburg Protocol), as amended in 2012, which establishes for its 26 Parties legally binding emissions reduction commitments for 2020 and beyond for major air pollutants: sulphur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3), volatile organic compounds (VOCs) and fine particulate matter (PM2.5). The Protocol is the only legally binding instrument in the world to reduce these key air pollutants on a broad regional basis.
Implementation of the Protocol to date, however, gives a mixed picture: collective efforts of Parties resulted in emission reductions between 2005 and 2019 that already exceed the combined targets envisaged for 2020, except for PM2.5. However, for individual Parties, there is a significant difference in the progress made toward meeting the emission reduction commitments, with ammonia, coming mostly from agriculture, being a major challenge for many. In addition, current commitments and legislation will not be sufficient to achieve the long-term objectives of the Protocol, which is to not exceed the target thresholds for ecosystems and health (critical loads and levels), which could cause long-term damage.
Additional action is needed by Parties to make faster progress towards meeting all their individual emission reduction commitments in 2020 and beyond, particularly.
in the agricultural sector (NH3 and the ground-level ozone precursor methane (CH4)), the energy sector (NOx), road transport (NOx, VOCs, black carbon (BC) and non-exhaust PM), (international) shipping (NOx), solvent use (VOCs), domestic wood burning (PM2.5, BC, and VOCs), agricultural residue burning (PM2.5 and BC), gas flaring (BC and CH4) and landfills (CH4). Still, science shows that even if the current legislation is fully implemented, more needs to be done to be able to achieve the long-term objectives of the Protocol.
“Since current legislation in the pan-European region and North America will not be sufficient to achieve long-term objectives to protect health and ecosystems from air pollution, this report clearly shows that additional action is needed across key sectors. Approaches that also address climate change, biodiversity loss, energy, transport, agricultural, and nitrogen management policies, can offer the most substantial, cost-effective emission reductions. UNECE stands ready to support countries to fully harness measures under the Air Convention”, says the Executive Secretary of UNECE, Olga Algayerova.
“Emissions of ammonia, black carbon, and the ground-level ozone precursor methane (CH4) increasingly require integrated environmental policy approaches, not only within, but also outside the region. The Convention needs to lead by example and stimulate emission reductions globally, also through the new Forum for International Cooperation on Air Pollution”, says the outgoing Chair of the Executive Body for the Convention, Anna Engleryd.
Ecosystems still at risk – climate change aggravates vulnerabilities
Monitoring under the Convention confirms that emission abatement actions have led to lower concentrations for most pollutants and to reduced impacts. For example, aquatic and terrestrial ecosystems have shown evidence of recovery from acidification since the 1990s. However, there are still risks of eutrophication as a result of nitrogen deposition for more than 50% of Europe’s ecosystems. Eutrophication describes the process of nitrogen loading of soils or waters, which often leads to a cascade of negative effects, such as algae blooms in waters. Emission reductions of nitrogen, specifically ammonia (NH3) from agriculture, therefore need to be greater to allow ecosystems’ recovery and prevent, among other issues, effects of nutrient imbalances on surface and groundwater quality, biodiversity, trees, and the resilience of forests to stress factors such as drought, wildfires or insect outbreaks. Higher temperatures due to climate change exacerbate these effects, increasing the likelihood of these stress factors, as has been shown by the many summer forest fires across the Northern Hemisphere in the last couple of years.
Health risks from air pollution persist
There are also still large exceedances of the WHO Air Quality Guidelines for PM2.5. In 2015, the report finds that more than 90% of the population in the region was still exposed to levels that exceed the Guidelines, with dire consequences for health, i.e. respiratory and cardiovascular diseases, cancer, and premature deaths. In 2021, 96% of the urban population in the EU was exposed to PM2.5 above the WHO Guideline level.
Air pollution causes food losses – dietary change can reduce emissions
While peaks of ground-level ozone, formed in the atmosphere by precursor emissions regulated under the protocol, such as VOCs, NOx, have declined systematically, annual mean background concentrations of ozone have increased over the 2000-2018 period. This not only has had consequences for health, but also for crops. For example, in 2015, estimated total wheat production losses for Europe due to ozone were 23.8M tonnes, greater than the annual production of Ukraine (21.8 M tonnes).
Production of meat and the widespread use of manure and fertilizers in agriculture are responsible for continued high ammonia emissions, with only modest reductions. The report finds that additional ammonia measures are required, which need – in some cases – to include non-technical measures, such as dietary changes, including reduction of meat consumption.
Even the most ambitious future emission reduction scenario is not enough to achieve long-term health and ecosystem goals
While current legislation will further deliver significant emission reductions in the short and longer term, scenarios show that it will not be sufficient to achieve the long-term objectives of the Protocol. For example, under a current legislation scenario, by 2050, only one-third of the population will meet the 2021 WHO air quality guideline for PM2.5 in the region; in 65 per cent of the ecosystem area in the European Union the nitrogen threshold will still be exceeded; and ground-level ozone will still lead to crop losses, for example, an average loss of 8 per cent of wheat yields in the northern hemisphere. This is mainly the result of the projected increases in global methane (CH4) emissions, which are expected to offset the decreases in ground-level ozone due to controls of precursors (NOx and VOC) within Europe and North America.
The long-term objectives of the amended Protocol will also remain a challenge in a scenario that assumes maximum technically feasible reductions. While this scenario assumes full penetration of the Best Available Techniques (BATs), technical measures alone will not be sufficient to protect ecosystems and health.
Even the most optimistic scenario for 2050, which assumes significant reductions as a result of global climate mitigation policy (including the Global Methane Pledge), and a significant transformation in the agricultural sector, associated with changes in the human diet, will still not achieve the long-term objectives of the Protocol. This scenario shows that 30 per cent of the population in the region will still be exposed to PM2.5 concentrations above the 2021 WHO guideline level and that, in 25 per cent of the ecosystem area, the nitrogen threshold will be exceeded. For wheat, total losses for Europe are predicted to fall by 7 million tonnes by 2050 (from 2015 production: 23.8 million), equivalent to the current wheat production of Poland. However, overall, results show that significant production losses of wheat due to ground-level ozone will still occur even under this most optimistic scenario, with an estimated 16.8 million tonnes lost for Europe.
More efforts needed: integrated policy approaches pay off
The report finds that since current legislation will not be sufficient to achieve the long-term objectives of the Protocol, as shown in the scenarios, additional action is needed, particularly in the agricultural sector (NH3 and CH4), the energy sector (NOx), road transport (NOx, VOCs, black carbon (BC) and non-exhaust PM), (international) shipping (NOx), solvent use (VOCs), domestic wood burning (PM2.5, BC, and VOCs), agricultural residue burning (PM2.5 and BC), gas flaring (BC and CH4) and landfills (CH4).
While technical measures will remain part of the solution to reduce emissions, the Best Available Techniques alone will not be sufficient to achieve them. Non-technical and structural measures, synergies with other policy fields, as well as additional efforts outside the region (e.g. methane and international shipping), will also be needed.
The report finds that the multi-pollutant, multi-effect approach is critical for cost-effective emission reductions. Scenario calculations show that if other pollutants and environmental concerns such as climate change, biodiversity loss, energy, transport, agricultural, and nitrogen management policies are further integrated, these policies could offer substantial, cost-effective emission reductions of air pollutants covered by the Protocol.
Special attention for future action needs to be given to CH4 as an ozone precursor, black carbon, and ammonia. To support climate action, more focus is needed on reducing emissions of air pollutants that have a warming effect, such as BC and ozone precursors (CH4). Methane reduction plays a key role in reaching synergetic effects, as it is both a greenhouse gas and an increasing determinant of ozone formation. Cost-effective technical solutions are available to reduce CH4 from fossil fuel production and waste treatment. To reduce CH4 from the biggest emitting sector in the region -agriculture -policy measures or behavioral change to reduce consumption of meat and dairy could offer synergetic benefits on health, climate, ozone formation, and nitrogen pollution.
Climate, air, and health synergies can also be reaped by reducing emissions of BC, which, when deposited onto ice and snow, accelerates melting – a significant issue regarding the Arctic and mountain glaciers.
A wider agricultural and integrated nutrient management approach could play an important role in meeting nitrogen deposition targets and halting biodiversity loss, while at the same time tackling water pollution and greenhouse gas emissions from agriculture (nitrous oxide (N2O) and CH4).