Canada’s Air Pollutant Emissions Inventory Report 2024: annex 3
Recalculations
Emission recalculation is an essential practice in the maintenance of up-to-date and consistent trends in air pollutant emissions. The Air Pollutant Emissions Inventory (APEI) is continuously updated with improved estimation methodologies, statistics and more recent and appropriate emission factors. As new information and data become available, previous estimates are updated and recalculated to ensure a consistent and comparable trend in emissions. Circumstances that warrant a change or refinement of data and/or methods include the:
- correction of errors detected by quality control procedures;
- incorporation of updates to activity data including changes to data sources;
- reallocation of activities to different categories (which will affect sub-totals);
- refinements of methodologies and emission factors; and
- inclusion of categories previously not estimated (which improves inventory completeness).
Resubmissions of facility-reported data previously reported to the National Pollutant Release Inventory (NPRI) can also result in revised historical estimates. Generally, these recalculations by facilities are completed for only a few years in their historical emissions.
In contrast, new activity data are incorporated into the in-house estimates as they become available, and these updates are reflected in the trends on an ongoing basis. Table 3-1 in Chapter 3 shows which sources are estimated using facility reported data and/or in-house methods. Updated trends, based on updated facility-reported data and in-house estimates, are published on a yearly basis. For example, the calculation of emissions from commercial fuel combustion, residential fuel combustion, Agricultural Fuel Combustion and Construction Fuel Combustion sources rely on the latest fuel use quantities from the Statistics Canada annual publication Report on Energy Supply and Demand in Canada (RESD) (Statistics Canada, n.d.).
A3.1 Recalculations in this Air Pollutant Emissions Inventory Edition
The following pollutants were not significantly recalculated (net emissions change <1%) between the 2023 and 2024 editions of the APEI with negligible impact on the time series trendline:
- sulphur oxides (SOx)
- nitrogen oxides (NOx)
- volatile organic compound (VOCs)
- carbon monoxide (CO)
- lead (Pb)
- cadmium (Cd)
- mercury (Hg)
- benzo(a)pyrene (B[a]p)
- benzo(b)fluoranthene (B[b]f)
- benzo(k)fluoranthene (B[k]f)
- indeno(1,2,3-cd)pyrene (I[-cd]p)
The following pollutants had notable recalculations between the 2023 and 2024 editions of the APEI:
- dioxins and furans
- hexachlorobenzene (HCB)
- ammonia (NH3)
- total particulate matter (TPM)
- particulate matter less than or equal to 10 microns in diameter (PM10)
- particulate matter less than or equal to 2.5 microns in diameter (PM2.5)
These recalculations are presented below (Figure A3–1 to Figure A3–6), all at the national level.
Figure A3–1 Recalculations to Dioxins and Furans
Long description for Figure A3-1
Figure A3-1: Recalculations to Dioxins and Furans
Figure A3-1 is a line graph comparing changes in dioxins and furans emissions (1990-2022) between the 2023 and 2024 editions. Dioxins and furans emissions have followed a similar trend for both the previous and current submissions, decreasing overall between 1990 and 2022. Specifically, a decrease in emissions is observed from 1997 to 2011, stabilizing from 2011 to 2022. The figure is accompanied by a table presenting changes in dioxins and furans emissions in grams of toxic equivalent as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of dioxins and furans in grams of toxic equivalent for the 2023 and 2024 editions of the APEI.
| Year | Dioxins and furans Emissions (gTEQ) 2023 NIR | Dioxins and furans Emissions (gTEQ) 2024 NIR | Change in Emissions (gTEQ) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 224 | 233 | 9.2 | 4.1% |
| 1991 | 231 | 242 | 11 | 4.8% |
| 1992 | 240 | 250 | 11 | 4.4% |
| 1993 | 244 | 253 | 8.4 | 3.4% |
| 1994 | 244 | 253 | 9.1 | 3.7% |
| 1995 | 239 | 245 | 5.9 | 2.4% |
| 1996 | 239 | 243 | 4.5 | 1.9% |
| 1997 | 237 | 246 | 9.9 | 4.2% |
| 1998 | 224 | 234 | 9.3 | 4.2% |
| 1999 | 214 | 224 | 10 | 4.7% |
| 2000 | 219 | 230 | 11 | 4.9% |
| 2001 | 213 | 221 | 7.5 | 3.5% |
| 2002 | 208 | 217 | 9.5 | 4.6% |
| 2003 | 207 | 217 | 10 | 5.0% |
| 2004 | 195 | 194 | -0.59 | -0.30% |
| 2005 | 168 | 170 | 2.5 | 1.5% |
| 2006 | 156 | 153 | -2.8 | -1.8% |
| 2007 | 148 | 144 | -4.6 | -3.1% |
| 2008 | 136 | 132 | -4.0 | -2.9% |
| 2009 | 125 | 122 | -2.9 | -2.3% |
| 2010 | 120 | 118 | -1.9 | -1.6% |
| 2011 | 87 | 87 | -0.10 | -0.11% |
| 2012 | 83 | 80 | -3.5 | -4.2% |
| 2013 | 82 | 78 | -3.9 | -4.8% |
| 2014 | 85 | 81 | -4.0 | -4.7% |
| 2015 | 88 | 83 | -4.6 | -5.2% |
| 2016 | 87 | 80 | -6.9 | -7.9% |
| 2017 | 87 | 83 | -3.8 | -4.3% |
| 2018 | 85 | 80 | -5.2 | -6.1% |
| 2019 | 85 | 85 | -0.26 | -0.30% |
| 2020 | 79 | 77 | -1.8 | -2.3% |
| 2021 | 82 | 83 | 1.1 | 1.3% |
| 2022 | NIL | 80 | NIL | NIL |
Figure A3–2 Recalculations to HCBs
Long description for Figure A3-2
Figure A3-2: Recalculations to HCBs
Figure A3-2 is a line graph comparing changes in hexachlorobenzene (HCB) emissions (1990-2022) between the 2023 and 2024 editions. HCB emissions have followed a similar trend for both the previous and current submissions. From 1990 to 2002, emissions increased and then decreased drastically from 2002 to 2003, followed by a gradual decrease until 2020. Subsequently, emissions slightly increased from 2020 to 2021 before decreasing again in 2022. The figure is accompanied by a table presenting changes in hexachlorobenzene emissions in kilograms as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of hexachlorobenzene in kilograms for the 2023 and 2024 editions of the APEI.
| Year | Dioxins and furans Emissions (gTEQ) 2023 NIR | Dioxins and furans Emissions (gTEQ) 2024 NIR | Change in Emissions (gTEQ) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 224 | 233 | 9.2 | 4.1% |
| 1991 | 231 | 242 | 11 | 4.8% |
| 1992 | 240 | 250 | 11 | 4.4% |
| 1993 | 244 | 253 | 8.4 | 3.4% |
| 1994 | 244 | 253 | 9.1 | 3.7% |
| 1995 | 239 | 245 | 5.9 | 2.4% |
| 1996 | 239 | 243 | 4.5 | 1.9% |
| 1997 | 237 | 246 | 9.9 | 4.2% |
| 1998 | 224 | 234 | 9.3 | 4.2% |
| 1999 | 214 | 224 | 10 | 4.7% |
| 2000 | 219 | 230 | 11 | 4.9% |
| 2001 | 213 | 221 | 7.5 | 3.5% |
| 2002 | 208 | 217 | 9.5 | 4.6% |
| 2003 | 207 | 217 | 10 | 5.0% |
| 2004 | 195 | 194 | -0.59 | -0.30% |
| 2005 | 168 | 170 | 2.5 | 1.5% |
| 2006 | 156 | 153 | -2.8 | -1.8% |
| 2007 | 148 | 144 | -4.6 | -3.1% |
| 2008 | 136 | 132 | -4.0 | -2.9% |
| 2009 | 125 | 122 | -2.9 | -2.3% |
| 2010 | 120 | 118 | -1.9 | -1.6% |
| 2011 | 87 | 87 | -0.10 | -0.11% |
| 2012 | 83 | 80 | -3.5 | -4.2% |
| 2013 | 82 | 78 | -3.9 | -4.8% |
| 2014 | 85 | 81 | -4.0 | -4.7% |
| 2015 | 88 | 83 | -4.6 | -5.2% |
| 2016 | 87 | 80 | -6.9 | -7.9% |
| 2017 | 87 | 83 | -3.8 | -4.3% |
| 2018 | 85 | 80 | -5.2 | -6.1% |
| 2019 | 85 | 85 | -0.26 | -0.30% |
| 2020 | 79 | 77 | -1.8 | -2.3% |
| 2021 | 82 | 83 | 1.1 | 1.3% |
| 2022 | NIL | 80 | NIL | NIL |
Recalculations to dioxins and furans and HCBs (Figure A3–1 and Figure A3–2) are primarily attributed to improved quantification methods in the Incineration and Waste source category; specifically, to an update to the Residential Waste Burning emission estimates. A methodological update determined that the population using open burning was lower than previously estimated. Additionally, the quantity of waste open burned per household was less than originally estimated and the types of materials typically burned were revised.
Figure A3–3 Recalculations to NH3
Long description for Figure A3-3
Figure A3-3: Recalculations to NH3
Figure A3-3 is a line graph comparing changes in ammonia (NH3) emissions (1990-2022) between the 2023 and 2024 editions. NH3 emissions have followed a similar trend for both the previous and current submissions, increasing overall between 1990 and 2022. From 1990 to 2004, emissions increased and then decreased until 2011. Subsequently, emissions increased overall until 2021 and decreased in 2022. The figure is accompanied by a table presenting changes in ammonia emissions in kilotonnes as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of ammonia in kilotonnes for the 2023 and 2024 editions of the APEI.
| Year | NH3 Emissions (kt) 2023 NIR | NH3 Emissions (kt) 2024 NIR | Change in Emissions (kt) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 395 | 395 | 0.6 | 0.1% |
| 1991 | 392 | 392 | 0.5 | 0.1% |
| 1992 | 404 | 405 | 0.5 | 0.1% |
| 1993 | 408 | 409 | 0.4 | 0.1% |
| 1994 | 423 | 424 | 0.4 | 0.1% |
| 1995 | 449 | 450 | 0.4 | 0.1% |
| 1996 | 466 | 466 | 0.5 | 0.1% |
| 1997 | 471 | 471 | 0.5 | 0.1% |
| 1998 | 471 | 472 | 0.5 | 0.1% |
| 1999 | 466 | 467 | 0.5 | 0.1% |
| 2000 | 475 | 476 | 0.4 | 0.1% |
| 2001 | 475 | 475 | 0.4 | 0.1% |
| 2002 | 483 | 484 | 0.4 | 0.1% |
| 2003 | 480 | 480 | 0.4 | 0.1% |
| 2004 | 494 | 494 | 0.4 | 0.1% |
| 2005 | 490 | 490 | 0.4 | 0.1% |
| 2006 | 478 | 479 | 0.6 | 0.1% |
| 2007 | 482 | 484 | 1.3 | 0.3% |
| 2008 | 474 | 476 | 1.8 | 0.4% |
| 2009 | 458 | 460 | 2.3 | 0.5% |
| 2010 | 449 | 452 | 2.6 | 0.6% |
| 2011 | 446 | 449 | 2.9 | 0.7% |
| 2012 | 461 | 464 | 2.9 | 0.6% |
| 2013 | 475 | 478 | 2.9 | 0.6% |
| 2014 | 466 | 469 | 2.7 | 0.6% |
| 2015 | 468 | 471 | 2.7 | 0.6% |
| 2016 | 468 | 471 | 2.8 | 0.6% |
| 2017 | 458 | 461 | 3.4 | 0.7% |
| 2018 | 474 | 478 | 3.9 | 0.8% |
| 2019 | 475 | 479 | 4.0 | 0.8% |
| 2020 | 488 | 492 | 4.5 | 0.9% |
| 2021 | 493 | 499 | 6.4 | 1.3% |
| 2022 | NIL | 482 | NIL | NIL |
Recalculations to NH3 (Figure A3–3) are primarily attributed to improved quantification methods and updated activity data in the Incineration and Waste, and Agriculture source categories. Specifically, refinements were made for waste disposal tonnages, export and incineration data, and landfill gas recovery data. Additionally, data available from a 2022 survey of waste incineration facilities was used to improve emissions estimates. For Agriculture, incorporation of a higher spatial resolution version of the 2021 Census of Agriculture and an update to land use mapping led to spatial reallocation and adjustments in livestock populations and crop areas.
Figure A3–4 Recalculations to TPM
Long description for Figure A3-4
Figure A3-4 : Recalculations to TPM
Figure A3-4 is a line graph comparing changes in total particulate matter (TPM) emissions (1990-2022) between the 2023 and 2024 editions. TPM emissions have followed a similar trend for both the previous and current submissions, increasing overall between 1990 and 2022, although emission trends for the 2023 edition have variations that are more significant than those of the 2024 edition. From 1990 to 2006, TPM emissions are relatively stable and then increase significantly between 2006 and 2013. Emissions continue to increase slightly until 2019, undergo a significant decrease in 2020, and then increase again until 2022. The figure is accompanied by a table presenting changes in TPM emissions in kilotonnes as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of total particulate matter in kilotonnes for the 2023 and 2024 editions of the APEI.
| Year | TPM Emissions (kt) 2023 NIR | TPM Emissions (kt) 2024 NIR | Change in Emissions (kt) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 20 549 | 20 764 | 215 | 1.0% |
| 1991 | 19 769 | 20 153 | 385 | 1.9% |
| 1992 | 19 665 | 20 126 | 460 | 2.3% |
| 1993 | 19 230 | 20 319 | 1 090 | 5.7% |
| 1994 | 20 350 | 21 113 | 763 | 3.8% |
| 1995 | 19 805 | 21 354 | 1 549 | 7.8% |
| 1996 | 20 389 | 21 256 | 867 | 4.3% |
| 1997 | 21 776 | 21 953 | 177 | 0.81% |
| 1998 | 19 650 | 21 939 | 2 289 | 12% |
| 1999 | 20 109 | 21 783 | 1 674 | 8.3% |
| 2000 | 19 514 | 21 549 | 2 035 | 10% |
| 2001 | 20 269 | 22 155 | 1 886 | 9.3% |
| 2002 | 19 596 | 21 606 | 2 010 | 10% |
| 2003 | 19 677 | 21 585 | 1 907 | 9.7% |
| 2004 | 19 370 | 21 425 | 2 055 | 11% |
| 2005 | 19 351 | 21 512 | 2 160 | 11% |
| 2006 | 20 100 | 21 202 | 1 102 | 5.5% |
| 2007 | 21 811 | 21 893 | 82 | 0.38% |
| 2008 | 23 053 | 22 500 | -553 | -2.4% |
| 2009 | 21 651 | 22 307 | 656 | 3.0% |
| 2010 | 23 218 | 22 929 | -289 | -1.2% |
| 2011 | 24 143 | 23 165 | -978 | -4.1% |
| 2012 | 26 515 | 24 387 | -2 128 | -8.0% |
| 2013 | 26 996 | 25 129 | -1 866 | -6.9% |
| 2014 | 26 511 | 25 046 | -1 465 | -5.5% |
| 2015 | 27 268 | 24 731 | -2 537 | -9.3% |
| 2016 | 27 337 | 23 992 | -3 345 | -12% |
| 2017 | 27 762 | 24 734 | -3 028 | -11% |
| 2018 | 28 173 | 25 814 | -2 358 | -8.4% |
| 2019 | 28 282 | 26 540 | -1 742 | -6.2% |
| 2020 | 26 021 | 23 690 | -2 331 | -9.0% |
| 2021 | 26 702 | 24 233 | -2 469 | -9.2% |
| 2022 | NIL | 24 530 | NIL | NIL |
Figure A3–5 Recalculations to PM10
Long description for Figure A3-5
Figure A3-5 : Recalculations to PM10
Figure A3-5 is a line graph comparing changes in emissions of particulate matter less than or equal to 10 microns in diameter (PM10) (1990-2022) between the 2023 and 2024 editions. PM10 emissions have followed a similar trend for both the previous and current submissions, increasing overall between 1990 and 2022, although emission trends for the 2023 edition have variations that are more significant than those of the 2024 edition. From 1990 to 2006, PM10 emissions are relatively stable and then increase more significantly between 2006 and 2013. Emissions continue to increase slightly until 2019, undergo a significant decrease in 2020, and then increase again until 2022. The figure is accompanied by a table presenting changes in PM10 emissions in kilotonnes as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of PM10 in kilotonnes for the 2023 and 2024 editions of the APEI.
| Year | PM10 Emissions (kt) 2023 NIR | PM10 Emissions (kt) 2024 NIR | Change in Emissions (kt) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 6 651 | 6 709 | 58 | 0.88% |
| 1991 | 6 412 | 6 518 | 106 | 1.7% |
| 1992 | 6 360 | 6 481 | 121 | 1.9% |
| 1993 | 6 241 | 6 546 | 305 | 4.9% |
| 1994 | 6 556 | 6 760 | 204 | 3.1% |
| 1995 | 6 351 | 6 791 | 440 | 6.9% |
| 1996 | 6 530 | 6 768 | 239 | 3.7% |
| 1997 | 6 934 | 6 972 | 38 | 0.55% |
| 1998 | 6 275 | 6 954 | 678 | 11% |
| 1999 | 6 464 | 6 965 | 502 | 7.8% |
| 2000 | 6 306 | 6 917 | 612 | 9.7% |
| 2001 | 6 476 | 7 050 | 574 | 8.9% |
| 2002 | 6 224 | 6 836 | 613 | 9.8% |
| 2003 | 6 267 | 6 847 | 580 | 9.2% |
| 2004 | 6 174 | 6 795 | 621 | 10% |
| 2005 | 6 200 | 6 855 | 655 | 11% |
| 2006 | 6 395 | 6 729 | 334 | 5.2% |
| 2007 | 6 897 | 6 927 | 30 | 0.44% |
| 2008 | 7 246 | 7 085 | -161 | -2.2% |
| 2009 | 6 784 | 6 985 | 201 | 3.0% |
| 2010 | 7 252 | 7 174 | -77 | -1.1% |
| 2011 | 7 546 | 7 267 | -278 | -3.7% |
| 2012 | 8 202 | 7 583 | -620 | -7.6% |
| 2013 | 8 330 | 7 790 | -540 | -6.5% |
| 2014 | 8 231 | 7 809 | -423 | -5.1% |
| 2015 | 8 424 | 7 684 | -740 | -8.8% |
| 2016 | 8 461 | 7 476 | -985 | -12% |
| 2017 | 8 556 | 7 661 | -895 | -10% |
| 2018 | 8 636 | 7 934 | -702 | -8.1% |
| 2019 | 8 674 | 8 156 | -518 | -6.0% |
| 2020 | 8 034 | 7 347 | -688 | -8.6% |
| 2021 | 8 240 | 7 488 | -752 | -9.1% |
| 2022 | NIL | 7 555 | NIL | NIL |
Figure A3–6 Recalculations to PM2.5
Long description for Figure A3-6
Figure A3-6 : Recalculations to PM2.5
Figure A3-6 is a line graph comparing changes in emissions of particulate matter less than or equal to 2.5 microns in diameter (PM2.5) (1990-2022) between the 2023 and 2024 editions. Overall, PM2.5 emissions have followed a similar trend for both the previous and current submissions, with emissions in 2022 being lower than those in 1990. Emission trends for the 2023 edition have variations that are more significant than those of the 2024 edition. For the trends of the 2023 edition, emissions undergo a significant decrease between 1990 and 2006. They then increase significantly until 2012 before stabilizing until 2019 and decreasing for 2020 and 2021. For the trends of the 2024 edition, emissions undergo a significant decrease between 1990 and 2006. Then, from 2006 to 2019, emissions undergo variations, experiencing a significant drop in 2020 and stabilizing until 2022. The emission trends for the 2024 edition are lower than those of 2023. The figure is accompanied by a table presenting changes in PM2.5 emissions in kilotonnes as well as in percentage between the 2023 and 2024 editions. The following table is the one appearing on the graph. The second table displays the emissions of PM2.5 in kilotonnes for the 2023 and 2024 editions of the APEI.
| Year | PM2.5 Emissions (kt) 2023 NIR | PM2.5 Emissions (kt) 2024 NIR | Change in Emissions (kt) | Change in Emissions (%) |
|---|---|---|---|---|
| 1990 | 1 664 | 1 663 | -1.4 | -0.09% |
| 1991 | 1 613 | 1 618 | 4.7 | 0.29% |
| 1992 | 1 578 | 1 577 | -0.24 | -0.02% |
| 1993 | 1 554 | 1 584 | 30 | 1.9% |
| 1994 | 1 589 | 1 596 | 7.4 | 0.47% |
| 1995 | 1 532 | 1 591 | 59 | 3.8% |
| 1996 | 1 542 | 1 563 | 21 | 1.4% |
| 1997 | 1 580 | 1 567 | -13 | -0.82% |
| 1998 | 1 399 | 1 522 | 123 | 8.8% |
| 1999 | 1 413 | 1 510 | 97 | 6.9% |
| 2000 | 1 373 | 1 496 | 123 | 8.9% |
| 2001 | 1 350 | 1 474 | 125 | 9.2% |
| 2002 | 1 275 | 1 407 | 132 | 10% |
| 2003 | 1 276 | 1 399 | 123 | 9.6% |
| 2004 | 1 242 | 1 370 | 129 | 10% |
| 2005 | 1 241 | 1 380 | 140 | 11% |
| 2006 | 1 248 | 1 321 | 72 | 5.8% |
| 2007 | 1 331 | 1 343 | 12 | 0.89% |
| 2008 | 1 393 | 1 364 | -29 | -2.1% |
| 2009 | 1 276 | 1 318 | 42 | 3.3% |
| 2010 | 1 346 | 1 340 | -6.2 | -0.46% |
| 2011 | 1 390 | 1 352 | -37 | -2.7% |
| 2012 | 1 495 | 1 391 | -104 | -7.0% |
| 2013 | 1 510 | 1 423 | -87 | -5.8% |
| 2014 | 1 504 | 1 439 | -66 | -4.4% |
| 2015 | 1 515 | 1 390 | -125 | -8.2% |
| 2016 | 1 507 | 1 330 | -177 | -12% |
| 2017 | 1 512 | 1 345 | -167 | -11% |
| 2018 | 1 522 | 1 384 | -137 | -9.0% |
| 2019 | 1 522 | 1 412 | -110 | -7.2% |
| 2020 | 1 442 | 1 299 | -143 | -9.9% |
| 2021 | 1 463 | 1 300 | -163 | -11% |
| 2022 | NIL | 1 299 | NIL | NIL |
Recalculations to particulate matter (TPM, PM10 and PM2.5) (Figure A3–4 to Figure A3–6) are primarily attributed to improved quantification methods in the Dust Construction Operations emission source and improved data used in the road Dust sources. A new model for construction dust was developed, which improved the activity data and emission factors used in the calculation of construction dust emissions. Refer to Annex 2 for additional details on APEI methodologies.
A3.2 Considerations for Future Editions of this Inventory
Further refinements and recalculations to the emission estimates are anticipated for subsequent editions of the APEI. Examples of planned improvements include the following:
- refinement of the road Dust traffic-distribution model to include a variable (evolving) road-network and provincial and territorial specific total kilometers driven
- introduction of in-house estimates for the Marine Cargo Handing sector using regional shipping quantities and wind speed data
- updated residential wood combustion emission factors based on Canadian data
- updated solvent emission factors based on Canadian data
Please contact apei-iepa@ec.gc.ca for more information on any methodological update or recalculations.
References, Annex 3, Recalculations
Statistics Canada. No date. Report on energy supply and demand in Canada (Annual), Catalogue No. 57 003 X.
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