Ireland's transboundary pollutants

• 03 Jan 2016
air quality

EU Member States must limit their national annual mass emissions of four so-called transboundary pollutants, in accordance with article 4.1 of the national emissions ceiling directive (2001/81/EC). Ceiling limits for sulphur dioxide (SO₂), oxides of nitrogen (NO_X), ammonia and volatile organic compounds (VOCs) have applied since 2010.

This article summarises the mass emission limits that Ireland was required to adhere to by 2010 and compares them with the actual emissions for 1990, 2005, 2010 and 2013 (provisional), as published by the Environmental Protection Agency (EPA). Ireland is currently meeting two of the national ceiling limits (SO₂ and ammonia) and is exceeding two others (NO_X and VOCs).

Sulphur dioxide (SO₂)

Emissions of SO₂ largely result from the combustion of fossil fuels. In the past, SO₂ was a major contributor to damage from acid rain. The table below shows that Ireland comfortably met its emissions ceiling limit for SO₂ in 2010 and is also expected to have done so for 2013 (provisional data).

The ~80% reduction achieved since the 1990 is due inter alia to:

• The installation of flue gas desulphurisation technology at the Moneypoint coal-fired power station in 2008/2009.
  
  
• The declining use of coal and other high-sulphur solid fuels by households.
  
  
• The increasingly stringent EU limits on the sulphur content of liquid hydrocarbon transport fuels.

Ammonia

Emissions from animal manures account for 87% of Ireland's ammonia emissions, with smaller amounts arising from chemical fertiliser use and road transport. The table below shows how emissions have been more or less constant since 1990, and how the 2010 emissions complied with the ceiling by a modest margin. The projected emissions value for 2013 is also below the ceiling.

Oxides of nitrogen (NO_X)

NO_X emissions have reduced by 33% since 1990, although the ceiling was exceeded in 2010 and the provisional data for 2013 also exceeded the ceiling (by 18%).

NO_X emissions from Moneypoint were reduced by the installation of selective catalytic reduction (SCR) technology in 2008, but this has been somewhat offset by the dramatic increase in transport fuel combustion.

Volatile organic compounds (VOCs)

A recently-introduced methodology added new categories of VOCs, including from agriculture, to the inventory computation. As a result, Ireland has exceeded the VOC ceiling, which was set before the new methodology was introduced. We understand that Ireland will seek to renegotiate a new ceiling for VOCs.

2020 and 2030

The national emission ceilings directive is being reviewed as part of the clean air policy package. The revised proposals will see the 2010 emissions ceilings continuing to apply up to 2020. New national emission reduction commitments will apply from 2020 and 2030 for the four pollutants discussed above, and new targets will be introduced for fine particulate matter (PM_2.5) and methane.

The new reduction commitments will take the form of target percentage reductions from a 2005 baseline and are expected to be ratified in 2016. Ireland’s reduction commitments will likely be set at 65% for SO₂, 1% for ammonia, 49% for NO_X and 25% for VOCs (all from a 2005 baseline - see table below). The relatively low reduction target for ammonia reflects the fact that agriculture is the dominant emitter and the plans for increased agricultural output to 2020 and beyond mean that greater reductions are not deemed feasible.