Acidifying emissions

  • Acidifying emissions reduced by 54% between 2000 and 2019

    Between 2000 and 2019, potentially acidifying emissions emissions decreased from 12,741 million to 5,808 million acid equivalents. This corresponds to a decrease of 54%. This figure is the sum of the emissions of 3 acidifying substances: sulphur dioxide (SO2), nitrogen oxides (NOx) and ammonia (NH3). This sum is expressed in acid equivalents, taking into account the acid-forming capacity of each substance.

    The decrease in potentially acidifying emissions between 2000 and 2019 is largely due to a significant decline in SO2 emissions (-82%). NH3 and NOx emissions dropped by respectively 31% and 49% in this period.

    In 2019, NOX (45%) and NH3 (42%) contributed the most to the acidifying emissions. The share of SO2 was much more limited (13%).

  • Agriculture main source of acidifying emissions

    Agriculture was in 2019 by far the most important source of potentially acidifying emissions (44%), followed by transport (29%), industry (15%) and energy (8%).

    The largest decrease between 2000 and 2019 occurred in the energy sector (-82%) and there was also a significant decrease in industry (-57%). Both sectors mainly emit NOX and SO2, and the decrease was mainly the result of emission-reducing measures.

    There was also a significant decrease in the transport sector (-52%). This mainly concerns the reduction in NOX emissions due to stricter emission standards.

    Agriculture, producing especially NH3 emissions, recorded a 34% decrease between 2000 and 2019. Agricultural emissions decreased mainly between 2000 and 2008 (due to fertilization standards, the reduction of livestock, the lower nitrogen content of animal feed, the use of low-emission animal manure and the construction of low-emission barns), remained more or less stable thereafter and decreased again slightly from 2017 onwards.

Sources

Flemish Environment Agency (VMM): acidifying emissions 

Definitions

Potentially acidifying emissionssum of the emissions of sulphur dioxide (SO2), nitrogen oxides (NOx (NO2)) and ammonia (NH3). This sum is expressed in acid equivalents (Aeq), taking into account the acid-forming capacity of each substance. The term ‘potentially’ acidifying emissions is used because the actual acidification also depends to a large extent on the processes involved between emission and deposition and on the various processes in the soil and (surface) water.

Publication date

28 September 2021

Next update

September 2022

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