aq_summary_t = aq.from(transpose(aq_summary))
aq_sources = aq_summary_t
.dedupe("sector_name")
.array("sector_name")
.sort()
aq_vars = new Map([
["Nitrogen Oxides", "NOx"],
["Carbon Monoxide", "CO"],
["Sulphur Dioxide", "SO2"],
["Ammonia", "NH3"],
["Particulate Matter (PM₁₀)", "PM10"],
["Fine Particulate Matter (PM₂.₅)", "PM2.5"],
["Volatile Organic Compounds", "VOC"],
["Lead", "Pb"]
])
aq_years = aq_summary_t.dedupe("emission_year").array("emission_year")
aq_summary_filtered = aq_summary_t.filter(aq.escape((d) => d.short_poll_name === aqVarChoice && aqSectorChoice.includes(d.sector_name)))
aq_summary_filtered_year = aq_summary_t.filter(aq.escape((d) => d.short_poll_name === aqVarChoice && d.emission_year == aqFocusYear))The charts below show information related to air quality emissions from Wales. Eight key pollutants are visualised, including gaseous species, particulate matter, volatile organic compounds, and metals. The data on this page can be downloaded from the National Atmospheric Emissions Inventory.
newPlot.plot({
marginLeft: 60,
marginTop: 40,
marginBottom: 40,
style: {
fontSize: 15,
},
width,
color: {
legend: true,
domain: aq_sources,
label: "Sector"
},
x: {
tickFormat: "",
interval: 1,
label: "Emission Year"
},
y: {
label: aqPercentAxis ? "% Contribution" : "Emissions (kilotonne)",
grid: true,
percent: aqPercentAxis
},
marks: [
newPlot.barY(
aq_summary_filtered.filter(aq.escape((d) => d.emission_year === aqFocusYear)),
newPlot.groupX(
{
y1: (D) => d3.sum(D, (d) => d > 0 ? d : 0),
y2: (D) => d3.sum(D, (d) => d < 0 ? d : 0)
},
{x: "emission_year", y: aqPercentAxis ? "p" : "emission", stroke: "black", strokeWidth: 5})
),
newPlot.barY(
aq_summary_filtered, {
x: "emission_year",
y: aqPercentAxis ? "p" : "emission",
fill: "sector_name",
tip: { format: { color: "d", x: "d" } }
}
)
]
})newPlot.plot({
width,
height: 200,
marginLeft: 60,
marginTop: 30,
marginBottom: 40,
style: {
fontSize: 15
},
y: {
label: "Contribution to total (%) in " + aqFocusYear
},
fx: {
label: "NFR Code"
},
color: {
type: "categorical",
domain: aq_summary_filtered_year.dedupe("sector_code").array("sector_code").sort(),
scheme: "Observable10",
legend: false
},
marks: [
newPlot.waffleY(
{ length: 1 },
{ y: 100, fillOpacity: 0.5, multiple: 10, fill: "#e2e2e2" }
),
newPlot.waffleY(
aq_summary_filtered_year,
{
fx: "sector_code",
y: (d) => d.p * 100,
fill: "sector_code",
tip: {
format: {
fill: false
}
},
round: false,
multiple: 10
}
)
]
})The bar chart shows emissions of eight different pollutants, which can be selected at the top of this page. Sources can be selected and deselected using the checkboxes. By default, the y-axis shows the total emissions in kilotonnes, but selecting “percentage axis” shows the relative sector proportions instead.
viewof aqSectorChoice = Inputs.checkbox(
aq_sources,
{label: "Sources", value: aq_sources}
)
viewof aqPercentAxis = Inputs.toggle({label: "Percentage Axis", value: false})
// "Focus year" for lower plots
viewof aqFocusYear = Inputs.range([Math.min(...aq_years), Math.max(...aq_years)], {label: "Breakdown year", step: 1, value: Math.max(...aq_years)})
Sectors & NFR Codes
Each of the air quality sources encompasses a number of sectors. These sources generally align with the NFR Codes used in the National Atmospheric Emissions Inventory. Select a sector name below to learn which sectors are included in each source.
aqDescription =
aqVarChoice == "NOx" ?
md`Emissions of nitrogen oxides in Wales were estimated to be 41kt in 2022, representing 6% of the UK total for nitrogen oxides. Emissions have declined by 61% since 2005, mainly due to changes in transport sources, particularly in road transport. Emissions from road transport have declined by 61% since 2005, which contributes 27% to the overall NOx trend. This is driven by the successive introduction of tighter Euro emission standards, and the continued penetration of vehicles which comply with these standards. In addition, improvements in catalyst repair rates resulting from regulations controlling the sale and installation of replacement catalytic converters and particle filters for light-duty vehicles contributes to the decline since 2008. However, the recent preferred uptake of diesel cars over petrol cars partly offsets these emissions reductions, because diesel cars emit higher NOX relative to their petrol counterparts. The reduction in emissions from energy industries more recently corresponds to the reduction in coal use at Aberthaw power station since 2013, but in particular between 2017 and 2019. As of 2022, NOx emissions from power stations have decreased by 87% since 2005, and are 91% lower than in 2013. **Between 2021 and 2022, emissions from NOx decreased by 2%, although emissions from transport (1A3) have increased by 3%. The overall decrease in NOx emissions is driven by a 12% decrease in iron and steel combustion emissions between 2021 and 2022.**` :
aqVarChoice == "CO" ?
md`Emissions of carbon monoxide in Wales were estimated to be 130kt in 2022 and have declined by 49% since 2005. Emissions in Wales accounted for 10% of the CO UK total in 2022. This decline in emissions stems from changes in the contribution of transport sources, particularly in the road transport sector where emissions have declined by 86% since 2005. This decline is primarily due to the penetration of vehicles compliant with more recent Euro standards, which required the fitting of emission controls (e.g. three-way catalytic converters) in new petrol vehicles. Improved catalyst repair rates resulting from regulations controlling the sale and installation of replacement catalytic converters and particle filters for light-duty vehicles in 2008 also contribute to the trend. More recently, the switch from petrol cars to diesel cars, which have lower associated CO emissions rates, has also contributed to the observed trend. In more recent years, the industrial combustion sector has been growing in importance. Emissions from industrial combustion have declined by 57% since 2005, and contribute 39% to the overall CO trend. In addition, levels of activity within the iron and steel industry subsector are increasingly important. Iron and steel process sources such as sinter plants, basic oxygen furnaces and blast furnaces, and combustion sources were the largest source in 2022, representing 49% of CO emissions. **From 2021 to 2022, emissions of CO decreased by 24%. This has been driven by a 67% decrease in emissions from stationary combustion in the iron and steel sector (1A2a), which contributes to 84% of the trend. This is assumed to be driven by the decline in steel production in Port Talbot.**` :
aqVarChoice == "SO2" ?
md`Emissions of sulphur dioxide in Wales were estimated to be 14kt in 2022, representing 11% of the UK total for sulphur dioxide. Emissions have declined by 78% since 2005, which has been driven mainly by reductions in energy industries emissions. Power stations alone have seen a 99% drop in emissions in 2022 compared to 2005, which coincides with the continued UK-wide shift in power generation fuel mix away from coal and towards natural gas, nuclear, and renewable sources. Trends in recent years are influenced by emissions from a range of energy industries (power generation, oil refining) as well as the use of solid fuels in the residential sector and production trends (and related coal use) in the iron and steel industry. **In 2022, emissions from sulphur dioxide increased by 4%. This has in part been driven by a 17% increase in residential emissions since 2021.**` :
aqVarChoice == "NH3" ?
md`Emissions of ammonia in Wales were estimated to be 23kt in 2022. These emissions are at a similar level in 2022 to 2005, increasing by 2%, and account for 9% of the UK total ammonia emissions. Agriculture sources have dominated the time series, with cattle manure management alone accounting for at least 32% of emissions throughout. Emissions increases since 2008 have been driven largely by emissions from manure management practices, particularly for dairy cattle, and from the application of urea-based fertilisers and digestate to soils. A decline in emissions from transport sources is observed since 2005: although initially implemented to target NOX emissions from road transport, increased prevalence in improved catalytic systems has contributed to the decline in emissions of NH3 from road transport. **In 2022, emissions from ammonia decreased by 3% since 2021, driven by decreases in emissions from inorganic nitrogen fertiliser applications.**` :
aqVarChoice == "PM10" ?
md`Emissions of PM10 in Wales were estimated to be 9kt in 2022 and have declined by 33% since 2005. These emissions account for 7% of the PM10 UK total in 2022. Unlike most other pollutants, the emission profile of PM10 is diverse. In order of % contribution to emissions in 2022, these sources include: industrial processes (40%), residential combustion (21%), transport sources (14%), agriculture (11%), and industrial combustion (5%). Iron and steel process sources such as sinter plants, basic oxygen furnaces and blast furnaces, and combustion sources, account for 17% of PM10 emissions in 2022. Recent trends have been influenced by each of these sectors, although there is no strong variation in overall emissions since 2011. In recent years, emissions from residential, commercial and public sector combustion have increased somewhat, and this is primarily due to increasing wood fuel use in the residential sector. **In 2022, PM10 emissions have decreased by 5% since 2021. This is primarily driven by a 17% decrease in emissions from iron and steel occurred between 2021 and 2022 which has a 68% contribution to the overall PM10 trend. In addition, a 50% decrease in emissions from petroleum refining (1A1b) also contributes to the overall PM10 trend.**` :
aqVarChoice == "PM2.5" ?
md`Emissions of PM2.5 in Wales were estimated to be 5kt in 2022 and have declined by 40% since 2005. These emissions account for 8% of the PM2.5 UK total in 2022. As with PM10, PM2.5 emissions have a large number of significant sources. However, process emissions tend to produce coarser PM fractions and as such, combustion emissions are of greater importance for PM2.5 compared to PM10. For PM2.5, the residential, commercial, and public sector combustion category (NFR 1A4, which also includes agricultural combustion and fishing vessels) accounts for 37% of 2022 emissions. The primary reasons for the declines in emissions since 2005 are the continued switch in the fuel mix used in electricity generation away from coal and towards natural gas, and reductions in emissions from the transport sector due to the turnover of the vehicle fleet, with the continued penetration of vehicles that comply with more stringent exhaust emissions standards overtime. However, declines in emissions have been offset by increases in emissions from the residential sector, and in particular, the combustion of wood. **In 2022, PM2.5 emissions decreased by 7% since 2021, which is largely driven by a 19% decrease in emissions from iron and steel production, contributing 59% to the overall PM2.5 trend. There has also been a 49% decrease in emissions from petroleum refining (1A1b) between 2021 and 2022, which contributes 32% to the overall PM2.5 trend.**` :
aqVarChoice == "VOC" ?
md`Emissions of non-methane volatile organic compounds in Wales were estimated to be 42kt in 2022, representing 6% of the UK total for NMVOCs. Emissions have declined by 35% since 2005. This reduction is mainly due to the 86% decrease in emissions from road transport, as well as decreases to fugitive sources, including evaporative losses of fuel vapour from petrol vehicles, since 2005. The decline in road transport contributes 39% to the overall NMVOC trend, and coincides with the increasing proportion of diesel-fuelled vehicles in the passenger fleet which are associated with lower emissions rates of NMVOCs. The reduction in emissions also occurs to a lesser extent due to the introduction of petrol vapour recovery systems at filling stations. Due to this large reduction in transport emissions, solvent processes are the most important source of NMVOC emissions in recent years, now accounting for 32% of NMVOC emissions, with the largestemissions arising from domestic solvent applications, and to a lesser extent industrial applications. Since 2005, NMVOC emissions from solvent use has decreased by 29%. Agriculture accounts for 31% of NMVOC emissions in Wales in 2022. Cattle manure management and animal manure represent for 53% and 29% of all agricultural emissions respectively. In contrast to the overall decreasing trend in NMVOC emissions since 2005, emissions from agriculture have increased by 18% since 2005. **In 2022, emissions from NMVOCs decreased by 5% since 2021. This is largely driven by a 9% decrease in emissions from solvent use, which contributes 63% to overall NMVOC trend from 2021 to 2022.**` :
aqVarChoice == "Pb" ?
md`Emissions of lead in Wales were estimated to be 26 tonnes in 2022, representing 17% of the lead UK total. Emissions have declined by 0.7% since 2005. Industrial processes remains the largest source of lead emissions across the timeseries, with iron and steel contributing 79% of emissions in 2022. **In 2022, emissions increased by 4% since 2021, with iron and steel contributing to 67% of the increase. The importance of the sector to overall emissions means that the volatility in levels of production at Port Talbot steelworks play a primary role in dictating interannual trends, particularly in recent years where emissions have been highly variable.**` :
md`...`function getKeyByValue(map, searchValue) {
for (let [key, value] of map.entries()) {
if (value === searchValue) {
return key;
}
}
return null; // or undefined if you prefer
}
function set(input, value) {
input.value = value;
input.dispatchEvent(new Event("input", {bubbles: true}));
}