Emissions to air; greenhouse gases and air pollutants
What does the research entail
Purpose
Determining Dutch emissions to the air, both greenhouse gases and air pollutants, broken down into stationary and mobile sources, and in accordance with international regulations.
Target population
Stationary sources are fires (such as furnaces, stoves and boilers), industrial process installations and other non-mobile activities with emissions to the air.
Mobile sources are means of transport (such as passenger cars, trucks, ships, trains and aircraft) and mobile equipment with a combustion engine (such as agricultural tractors, forklift trucks and (road) construction machines).
Statistical unit
Companies (according to the Dutch Standard Industrial Classification, SIC) and households.
Start of research
1990
Frequency
Annually (greenhouse gases and air pollutants)
Quarters (as of 2019; for greenhouse gases only)
Publishing Strategy
For the annual estimates, the provisional figures are published approximately nine months after the reporting year. About five months later, these figures will be given a definitive status.
When the figures for the most recent reporting year are given a definitive status, the figures for previous reporting years are also revised. The annual (re)calculation of the complete time series from 1990 onwards is internationally prescribed, so that the latest insights, especially with regard to emission factors, can be included in the calculations.
The quarterly estimates of greenhouse gas emissions are published approximately two and a half months after the end of a reporting quarter. The quarterly figures of the current year have a provisional status, just like the four quarterly estimates of the previous year (by provisional status of the corresponding annual estimate). With each adjustment of an annual estimate, such as with the annual (re)calculation of the complete time series, the underlying quarterly estimates are adjusted in such a way that the sum of the four quarters remains equal to the annual figure.
How is it performed
Type of research
The research takes place within the partnership of the Dutch Pollutant Release and Transfer Register (PRTR), in which approximately ten organizations participate. The PRTR is managed by the National Institute for Public Health and the Environment (RIVM).
Observation method
In the PRTR, Statistics Netherlands (CBS) is responsible for supplying activity data from, among other things, energy, traffic, agriculture and manure statistics. Activity data concerns, for example, the amount of fuel consumption, the number of vehicle kilometres, the number of animals in livestock farming, and the amount of manure. The emissions are calculated for each emission source by multiplying the source activity by an emission factor.
The fuel-related CO2 emission factors come from the annually established national fuel list, see NIE website (NIE = National Inventory Entity). The other emission factors are generally not supplied by CBS, but by other organizations in the PRTR, based on (literature) research and measurements. The emission calculations also use verified company-specific emission data from the Dutch electronic Environmental Annual Report (e-MJV).
After the PRTR has officially established the calculated and verified emissions, they are published by CBS in the following StatLine tables:
- Emissions of greenhouse gases according to IPCC guide-lines
- Emissions of air polluting substances according to NEC guide-lines
- Emissions to air on Dutch territory; totals
- Emissions to air on Dutch territory; stationary sources
- Emissions to air on Dutch territory; mobile sources
The figures in the first two tables correspond to the Dutch deliveries to the United Nations (UN) and the European Union (EU), see the IPCC figures (Intergovernmental Panel on Climate Change) associated with global emissions of greenhouse gases and the NEC figures (National Emission Ceilings) for global emissions of air pollutants. These websites also contain extensive methodological reports, which are provided annually together with the figures.
The last three tables contain emissions of both greenhouse gases and air pollutants. These emission figures differ slightly from the international figures (IPCC and NEC), because they are made for national purposes. They are important for (regional) modeling of concentrations in the air above Dutch territory.
In 2020, CBS developed an estimation method for IPCC quarterly figures. These quarterly figures are consistent with the annual figures estimated by the PRTR. See StatLine table: Emissions of greenhouse gases according to IPCC guide-lines, quarter.
What is the quality of the results
Accuracy
In accordance with international regulations, the Emissions Registration performs an annual Monte Carlo analysis to determine the uncertainty in emission figures (see IPCC and NEC reports). For greenhouse gases, the uncertainty is equal to 3 percent for carbon dioxide (CO2), 9 percent for methane (CH4), 28 percent for nitrous oxide (N2O) and 26 percent for fluorine-containing gases. For air pollutants, this is 17 percent for nitrogen oxides (NOx), 20 percent for sulfur oxides (SOx), 28 percent for ammonia (NH3) and 50 percent for volatile organic compounds, excluding methane (NMVOC). For particulate matter, it depends on the particle size: the uncertainty is 27 percent for particles with a diameter smaller than 10 micrometers (PM10) and 39 percent for particles smaller than 2.5 micrometers (PM2.5). This concerns the 95% confidence interval around the national emission total for the reporting year 2019. Other reporting years present slightly different uncertainties. The order of magnitude remains the same.
Sequential comparability
The time series from 1990 onwards are always sequentially comparable, because international regulations require that the complete time series be revised annually. Progressive insight (better activity data, emission factors and calculation method) is not only processed in recent reporting years, but also in the years before (up to the starting year 1990).
Description quality strategy
Legally speaking, the responsibility for estimating emission figures of sufficient statistical quality does not lie primarily with Statistics Netherlands (CBS), but with the Dutch Pollutant Release and Transfer Register (PRTR). However, just like the other organizations participating in the PRTR, CBS does give formal approval for the annual determination of the provisional and final emission figures. With this, CBS conforms to the same emission figures as those of the PRTR.
An exception to this are the air emission figures published by CBS from the Dutch Environmental Accounts. From a legal point of view, CBS is primarily responsible for the statistical quality of the Environmental Accounts figures. The conceptual calculation framework of the Environmental Accounts differs from the calculation frameworks that the PRTR uses and the figures are therefore not exactly the same. A relevant StatLine table in line with the Environmental Accounts is: Emissions to air by the Dutch economy; national accounts.