The emission of air pollutants has decreased significantly over the past decades and is expected to continue to decline in the coming years. This greatly increases the chance that European emission targets for air pollutants will be achieved by 2030. However, despite a significant reduction in ammonia emissions due to the lifting of the derogation, legal national targets for nitrogen deposition on nature are far out of reach. This conclusion is drawn by the Netherlands Environmental Assessment Agency (PBL) in its Emission Projections for Air Pollutants (ERL) 2025. The projections have been made by PBL and RIVM, with contributions from TNO and WUR.
Air pollution is harmful to human health and nature. Every two years, PBL maps estimated emissions of nitrogen oxides (NOx), ammonia, fine particulate matter (PM2.5), sulfur dioxide, and non-methane volatile organic compounds (NMVOCs). This is required under the European NEC directive, which aims for a steady reduction of the blanket of air pollution across the EU. The likelihood of meeting the European NEC emission targets for 2030 is very high, especially due to European emission requirements for mobility and industry, and climate and manure policy.
Estimated NOx Emissions Decline Faster than Ammonia Emissions
Three-quarters of the nitrogen deposition in nitrogen-sensitive Natura 2000 areas from Dutch sources comes from agriculture, mainly due to ammonia emissions. The rest comes mainly from NOx from traffic and industry. In the period leading up to 2030, the estimated NOx emissions will decline one and a half times faster than ammonia emissions. Between 2030 and 2035, NOx emissions will continue to decline at the same rate, while the decline in ammonia emissions flattens. You can see that until 2030 and thereafter, NOx emissions will continue to decline significantly due to climate and source policy, while the decline in ammonia emissions lags behind, says PBL director Marko Hekkert.
Ammonia Emissions Decline More Than in Previous Projection
Due to a derogation, Dutch farmers are allowed to apply more manure than prescribed by the Nitrate Directive. As of January 1, 2026, this derogation will be lifted. As a result, and due to termination schemes and low-emission stables, national ammonia emissions from agriculture are expected to decrease from 110 kton in 2022 to 90 kton in 2030. Roughly half of this is due to the lifting of the derogation. The new projection is 15 percent lower than the projection for agriculture in 2030 from ERL 2023.
Nitrogen Deposition Target in Environmental Act Far Out of Reach
According to the Environmental Act, by 2035, nitrogen deposition in 74 percent of nitrogen-sensitive Natura 2000 areas must be below the critical deposition value (CDV), with an interim target of 50 percent by 2030. According to a recent calculation by RIVM, ammonia emissions from agriculture must be 70 to 80 percent lower by 2035 than the projection from ERL 2023 to meet the target from the Environmental Act, assuming that there is no additional emission reduction in other sectors beyond the projection. To achieve the interim target for 2030, a reduction of about 55 to 65 percent is needed compared to the ERL 2023 projection. There is thus a large gap with the currently projected additional reduction of 15 percent compared to the ERL 2023 projection for both 2030 and 2035. This gap has largely arisen because new scientific insights have led to the establishment of new CDVs, which are significantly lower for many areas. Based on the old CDVs, a reduction of 33 percent compared to ERL 2023 was sufficient to meet the 2035 target.
Inland Shipping Requires Attention in Clean Air Agreement
The Clean Air Agreement (SLA) is an agreement between the central government, provinces, and municipalities. The main goal is to achieve at least 50 percent health gains by 2030 compared to 2016 through better air quality. Based on ERL 2023, 46 percent health gains were achieved. The extent to which the current projection will provide improvement will still be calculated by RIVM. A sub-target in the agreement of declining emission trends for NOx and fine particulate matter (PM2.5) in various sectors is very likely to be achieved. In particular, a sub-target for inland shipping still requires attention. This has a specific target of 35 percent emission reduction for nitrogen oxides (NOx) by 2035 compared to 2015. It is unlikely that this target will be met.
Climate and Manure Policy Contribute to Cleaner Air
European and national emission standards have led to a significant decrease in emissions across all sectors and will contribute to further reductions in the coming years. Particularly in mobility, this will be decisive for further declines in the coming years. The main goal of this successful source policy is to make the air cleaner. However, policies with other objectives, such as climate and manure policy, have also led to a significant additional reduction in air pollutants in the coming years. NOx is primarily generated during combustion processes. Because climate policy reduces the use of fossil fuels, it directly leads to a reduction in NOx emissions in industry and the energy sector. The phase-out of coal in power plants and a projected decrease in production at oil refineries will lead to lower emissions of sulfur dioxide, which has already decreased dramatically over the past decades. Manure policy, aimed at improving water and soil quality, leads to lower ammonia emissions.