Relative contribution of key human-made emission sources

  • Image, Relative contribution human-made emission sources.

    2018 air indicators are now available

    Burning wood and coal for home heating, road motor vehicle use, industrial activities, and household outdoor burning are the key human-made sources of air pollutants in New Zealand. These pollutants have a range of health effects. Monitoring the relative contribution of each source helps us understand their pressures on our air quality.

    We classified Relative contribution of key human-made emissions as a case study.

    Key findings

    • Of the four main human-made sources of key pollutants:
      • burning wood and coal for home heating is the main source of particulate matter 10 and 2.5 micrometres or less in diameter (PM10 (58 percent) and PM2.5 (63 percent))

      • industrial activities are the main source of sulphur oxides (SOx) (95 percent)
      • road motor vehicles are the main source of nitrogen oxides (NOx) (72 percent) and carbon monoxide (CO) (48 percent).

    • Household outdoor burning is not the main source of any particular pollutant, but contributes to a range of pollutants, particularly PM10 (7 percent) and PM2.5 (8 percent).
    • PM10 is of particular concern in New Zealand because of the high concentrations in some locations and its potential to contribute to serious health effects. The four key sources contributed these amounts to their combined annual PM10 emissions:
      • burning wood or coal for home heating, 58 percent
      • industrial activities, 27 percent
      • road motor vehicles, 8 percent
      • household outdoor burning, 7 percent.
    • Home-heating emissions are more common in winter. The four key sources contributed different relative amounts of pollutants during these cooler months, in particular PM10, PM2.5, and carbon monoxide.

    Note that reported emissions of SOx do not include emissions from road motor vehicles, which are expected to be low.

    Figure 1

    Note: Industry emissions estimates use data from 2008 to 2013. Estimates of other sources use data from 2013. Sulphur oxides emissions are not estimated for road motor vehicles. These emissions are expected to be low. PM10 – particulate matter 10 micrometres or less in diameter; PM2.5 – particulate matter 2.5 micrometres or less in diameter; NOx – nitrogen oxides; SOx – sulphur oxides; CO – carbon monoxide.

    Figure 2

    Note: Sulphur oxides emission estimates are not made for road motor vehicles. These emissions are expected to be low. Industry emissions estimates use data from 2008 to 2013. Estimates of other sources use data from 2013. PM10 – particulate matter 10 micrometres or less in diameter; PM2.5 – particulate matter 2.5 micrometres or less in diameter; NOx – nitrogen oxides; SOx – sulphur oxides; CO – carbon monoxide.

    Figure 3

    Note:  Sulphur oxides emissions are not estimated for road motor vehicles. These emissions are expected to be low. Industry emissions estimates use data from 2008 to 2013. Estimates of other sources use data from 2013. PM10 – particulate matter 10 micrometres or less in diameter; PM2.5 – particulate matter 2.5 micrometres or less in diameter; NOx – nitrogen oxides; SOx – sulphur oxides; CO – carbon monoxide.

    Figure 4

    Note: Sulphur oxides emission estimates are not made for road motor vehicles. These emissions are expected to be low. Industry emissions estimates use data from 2008 to 2013. Estimates of other sources use data from 2013. PM10 – particulate matter 10 micrometres or less in diameter; PM2.5 – particulate matter 2.5 micrometres or less in diameter; NOx – nitrogen oxides; SOx – sulphur oxides; CO – carbon monoxide.

    Definition and methodology

    Burning wood and coal for home heating, road motor vehicle use, industrial activities, and household outdoor burning are the main human-made sources of key pollutants in New Zealand.

    Measuring their relative contribution allows us to track changes in emissions from different sources and the possible effects on our air quality. For example, from 2006 to 2013, PM10 emissions from road motor vehicles decreased 25 percent. However, this source contributed only 9 percent of the total national PM10 emissions from the four key sources. This decrease in PM10 emissions from road motor vehicles likely had only a minor effect on total PM10 emissions.

    Over 95 percent of PM10 exceedances occur during May to August (the colder months). This can be attributed to greater emissions from burning wood or coal for home heating and more settled weather conditions (reducing the dispersal of pollutants) during these months.

    Data quality

    We classified Relative contribution of key human-made emissions as a case study.

    Relevance

    This case study is a partial measure of four topics: ‘Emissions of key pollutants from residences’, ‘Emissions of air pollutants from industrial activities’, ‘Emissions of air pollutants from primary industries’, and ‘Emissions of air pollutants from transport’.

    Accuracy

     The accuracy of the data source is of medium quality.

    See Data quality information for more detail.

    Supporting information

    Relative contribution of other human-made emissions

     

    Updated 17 December 2015

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