3. Air quality improvements and health benefits of air pollution policies
This chapter presents the projected emissions and concentrations of air pollutants in Arctic Council countries to 2050 under two scenarios: the baseline Current Legislation scenario (CLE) and a policy scenario reflecting the Maximum Technically Feasible Reduction in emissions of air pollutants in Arctic Council countries (MTFR-AC). The chapter begins by outlining the projections for the key air pollutants: sulphur dioxide, nitrogen oxides, black carbon, organic carbon, carbon monoxide, non-methane volatile organic compounds and ammonia. It then looks at projections for fine particulate matter and ground-level ozone concentrations. Finally, the chapter quantifies projections of the health impacts of the scenarios in terms of morbidity and mortality reductions, highlighting the benefits of policy-induced technical changes for air quality and human health.
Based on existing policies, emissions in Arctic Council countries are projected to decrease in the coming decades, even in the absence of additional policy action (baseline CLE scenario).1 Altogether, under the baseline scenario, by the middle of the century Arctic Council countries are projected to see emissions fall by 25% to 40%, depending on the pollutant2 (Figure 3.1). Emissions of SO2 are projected to decrease by 40% by 2025 and to then decrease only marginally by 2050. Strong abatement of SO2 emissions has already taken place prior to 2013, so by 2025 most of the abatement potential is exhausted. Emissions of other pollutants are projected to decrease more substantially over time. However, according to the GAINS model projections, Arctic Council countries are projected to achieve an aggregate BC emission reduction of 21% by 2025 compared to 2013 in the baseline scenario, coming close to their aspirational collective target of reducing these emissions by 25-33%.3
Although emissions are set to decline in Arctic Council countries even in the absence of additional policies, the implementation of policies to deploy the best available techniques could achieve much greater air quality improvements (Figure 3.1). Indeed, under the scenario of Maximum Technically Feasible Reduction in Arctic Council countries (MTFR-AC), NOX, SO2, and CO emissions are projected to decrease by 60% by the middle of the century. In addition, the MTFR-AC scenario would also allow a collective reduction of BC emissions by 65% by 2025, thus significantly exceeding the countries’ reduction target.
Note: For each bar in this figure, the sum of dark and light colours represents emission levels under CLE, while dark colours alone represent emission levels under MTFR-AC. CLE: Current Legislation baseline scenario; MTFR-AC: Maximum Technically Feasible Reduction in Arctic Council countries scenario.
Source: IIASA’s GAINS model.
However, BC emission projections for individual countries display large differences (Figure 3.2). With current policies, the largest emission reductions in percentage change compared to 2013 levels would take place in Nordic countries, which are projected to halve their emissions by 2025 under the CLE scenario. By 2025, most Arctic Council countries are projected to be close to meeting their emission reduction potential for several pollutants, with current legislation. As a consequence, the additional emission reductions under the MTFR-AC scenario are relatively small. Conversely, Russia4 is projected to experience larger emission reductions under the MTFR-AC scenario.
The aggregate emission reductions result from different sectoral contributions to overall abatement, which vary by pollutant. Most abatement of SO2 and NOX takes place in the energy and industrial sectors, whereas emissions of CO are mostly reduced in the transport sectors. BC emissions are projected to be reduced most in the residential sector (Figure 3.3). These sectoral emission reductions are not necessarily proportional to the sector-specific investments and they lead to reduced emissions for different pollutants (Figure 3.3). The benefits of the sectoral investments in terms of emission reductions depend on the cost of the BATs and their efficiency. For example, emission reductions in the residential sectors are more costly than in other sectors, but they are also most efficient in reducing black carbon emissions. Furthermore, these costs may fall on different stakeholders depending on the sector, while the benefits may be seen elsewhere. For example, reducing residential wood-burning emissions can be costly, and households might only benefit marginally from improved air quality. While there are differences in costs and resulting emission reductions of each sector, a full cost-benefit analysis by sector is beyond the scope of this report.
Note: BATs: best available technologies; BC: black carbon; CO: carbon monoxide; NOx: nitrogen oxides; PPP: purchasing power parity; SO2: sulphur dioxide
Source: IIASA’s GAINS model.
Thanks to the declining emission trends in Arctic Council countries, atmospheric concentrations of PM2.5 are projected to decrease even in the absence of further policy action (Figure 3.4, Panel A). However, by 2050 the additional policies in the MTFR-AC scenario would lead to an even greater improvement in air quality, especially in urban areas5 (Figure 3.4, Panel B). Furthermore, under the CLE scenario only a limited area in the north of the Arctic has PM2.5 concentration levels close to zero, while in the MTFR-AC scenario, a larger part of the Arctic would have near-zero emissions.
To better understand these air quality improvements, the concentration levels can be compared to the World Health Organisation’s (WHO) Air Quality Guidelines (Box 3.1) (WHO, 2005[1]). The guidelines for PM2.5 indicate a target value of 10 µg/m3 average annual concentrations. However, there could still be negative health impacts from air pollution below this level. The calculations of the health risks linked with exposure to PM2.5 used in this report rely on the Global Burden of Disease’s Integrated Exposure-Response functions (Cohen et al., 2018[2]; Burnett et al., 2014[3]), which set the zero risk threshold at 2.5 µg/m3 concentrations of PM2.5 (see Annex B).
The WHO air quality guidelines provide guidance on exposure levels to air pollutants that are dangerous to human health. Relevant to this report are the guidelines for particulate matter and ground-level ozone. These guidelines were issued for the first time in 1987; they were updated in 2005 and are currently under revision. In addition to the guidelines, the WHO has also issued some “interim targets” (Table 3.1). The interim targets can be considered as intermediate objectives to incrementally improve air quality up to the guideline value. Intermediate targets are particularly useful for regions that are affected by more severe pollution, where a direct achievement of the air quality guidelines would be more difficult.
Under the CLE scenario, concentrations of PM2.5 are projected to remain above the levels recommended by the WHO’s Air Quality Guideline value in several areas (red areas in Figure 3.4, Panel A). However, in the MTFR-AC scenario, average concentrations of PM2.5 are projected to fall below the guideline value in Arctic Council countries by 2050 (Figure 3.4, Panel B). The United States and Russia still have higher levels of concentrations of PM2.5 than other Arctic Council countries, but, on average, they also have the largest improvements compared to the CLE scenario.
This improvement in air quality would reduce the number of people exposed to fine particles at concentrations above the WHO guidelines (Figure 3.4). According to the projections for 2050, with existing policies (the CLE scenario), 8% of the population living in Arctic Council countries would be exposed to concentration levels of PM2.5 above the WHO guidelines. However, in the MTFR-AC scenario only 1% would be exposed to these concentrations. This decrease is equivalent to a change from 18 million people being exposed to concentrations higher than the WHO guidelines in the CLE scenario to 1 million people in the MTFR-AC scenario. Furthermore, while under the CLE scenario only 16% of the population would be exposed to very low PM2.5 air pollution levels (with concentrations below 2.5 micrograms per cubic metre), under the MTFR-AC scenario this share of the population would rise to more then 50%.
Note: The highest threshold (10 μg/m3) refers to the WHO Air Quality Guidelines, while the lowest (2.5 μg/m3) to the threshold under which the Global Burden of Disease functions consider that PM2.5 pollution does have significant health impacts. μg/m3: micrograms per cubic metre.
Source: EC-JRC’s TM5-FASST model.
In the CLE scenario, the seasonal average of daily maximum eight-hour concentrations of ground-level ozone is projected to increase to 2050 in all the Arctic Council countries. However, with additional policy action in the MTFR-AC scenario, ground-level ozone concentrations would slightly decrease in 2050, with stronger effects in the United States and Russia (Figure 3.6).6 Compared to PM2.5, the longer lifetime of ground-level ozone in the atmosphere makes it more dependent on historical emissions, weather conditions and emissions from neighbouring countries. Thus, even when Arctic Council countries reduce emissions of ground-level ozone precursor gases, the decrease in concentrations is limited.
In Arctic Council countries, fine particulate matter and ground-level ozone are responsible for more than 200 000 deaths every year. Despite the projected improvement in air quality in Arctic Council countries by the middle of the century, projected population growth and urbanisation mean that, in the absence of additional policy action, an increasing number of people are set to be exposed to air pollution in the region. Therefore, the total number of deaths linked to exposure to PM2.5 and ground-level ozone7 in Arctic Council countries is projected to remain approximately constant over time. As illustrated in Figure 3.7, under the CLE scenario, deaths attributable to these air pollutants in the Arctic Council region are projected to decrease from 225 000 in 2025 to 216 000 in 2050.8
The full deployment of the best available techniques to reduce air pollution in Arctic Council countries (MTFR-AC scenario) could result in at least 61 000 fewer deaths from PM2.5 and ground-level ozone every year by 2025 compared to the current policies scenario; 70 000 fewer deaths per year by 2030 and 80 000 fewer per year by 2050 (Figure 3.7). Overall, by the middle of the century, 4 out of 10 air pollution-related deaths could be avoided. While this reduction in mortality is a positive outcome of the air pollution policies, it is not as large as it could be given the large size of the emissions reductions. Air pollution causes mortality and illness even at low levels and, despite the emission reductions, air pollution persists especially in urban areas.
Notes: In the graph, for each bar, the sum of grey and blue colours reflect CLE levels, while the grey colour alone reflects MTFR-AC levels. While this report presents a single value estimate for the health impacts, there is an uncertainty range, which is discussed in (OECD, 2016[4]).
Source: ENV-Linkages’ model projections, based on Global Burden of Disease (GBD, 2018[5]).
The projected reductions in air pollution-driven mortality vary significantly across countries (Figure 3.8). For example, the benefits experienced by Iceland are very small, as the country is projected to already nearly reach its full emission reduction potential under the CLE scenario. Conversely, most of the other Arctic Council countries are projected to experience substantial benefits. These benefits are also projected to increase over time. Thus, by 2050, the deployment of the best available techniques included in the MTFR-AC scenario could reduce 36% of pollution-driven mortality in most Arctic Council countries (Figure 3.8).
Note: In the graph, for each bar, the sum of grey and blue colours reflect CLE levels, while the grey colour only reflects MTFR-AC levels.
Source: ENV-Linkages’ model projections, based on Global Burden of Disease (GBD, 2018[5]).
The implementation of more stringent policies targeting air pollution would not only reduce air pollution-related mortality, it would also decrease morbidity effects (i.e. the incidence of illness).9 While in the absence of further policy action the morbidity impacts of air pollution are projected to remain roughly constant until the middle of the century, the implementation of the best available techniques would significantly reduce the incidence of illness, with the most significant benefits resulting after 2025 (Table 3.2). For example, the avoided days of children suffering from asthma symptoms would amount to 2.2 million in 2025 and to 3 million in 2050. Furthermore, by the middle of the century, the MTFR-AC scenario would avoid 33 million lost workdays every year. Similarly, by 2050, air pollution-related hospital admissions are projected to fall by 60% compared to the CLE scenario for the same year.
The decrease of morbidity impacts will result in healthcare savings for Arctic Council countries. Healthcare savings calculated in this report are attributed to fewer cases of bronchitis in children and adults and a reduction in hospital admissions. In 2025, reduced air pollution from the implementation of policy action promoting deployment of BATs will save USD 1.3 billion (2017 PPP) in health expenditures, rising to USD 1.8 billion (2017 PPP) by 2050.
References
[8] AMAP (2019), Review of Reporting Systems for National Black Carbon Emissions Inventories, https://www.amap.no/documents/doc/eua-bca-technical-report-2/1780 (accessed on 16 December 2019).
[10] Arctic Council (2019), Expert Group on Black Carbon and Methane - Summary of Progress and Reccomendations, https://oaarchive.arctic-council.org/handle/11374/2411 (accessed on 8 December 2020).
[3] Burnett, R. et al. (2014), “An integrated risk function for estimating the global burden of disease attributable to ambient fine particulate matter exposure”, Environmental Health Perspectives, Vol. 122/4, pp. 397-403, https://doi.org/10.1289/ehp.1307049.
[2] Cohen, A. et al. (2018), “Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter”, Proceedings of the National Academy of Sciences, Vol. 115/38, pp. 9592-9597, https://doi.org/10.1073/pnas.1803222115.
[5] GBD (2018), Global Burden of Disease Study 2017: All cause Mortality and Life Expectancy 1950-2017, Global Burden of Disease Collaborative Network., Seattle, United States: Institute for Health Metrics and Evaluation (IHME).
[6] Holland, M. (2014), Cost-benefit Analysis of Final Policy Scenarios for the EU Clean Air Package, Corresponding to IIASA TSAP Report No. 11, International Institute for Applied Systems Analysis (IIASA), Laxenburg, http://ec.europa.eu/environment/air/pdf/TSAP%20CBA.pdf (accessed on 9 March 2021).
[7] Institute for Health Metrics and Evaluation (IHME) (2018), Global Life Expectancy, All-Cause Mortality, and Cause-Specific Mortality Forecasts 2016-2040, Seattle, United States: Institute for Health Metrics and Evaluation (IHME), https://vizhub.healthdata.org/gbd-foresight/ (accessed on 2 December 19).
[9] Klimont, Z. et al. (forthcoming), “Global scenarios of anthropogenic emissions of air pollutants: ECLIPSE”.
[11] Klimont, Z. et al. (2017), “Global anthropogenic emissions of particulate matter including black carbon”, Atmospheric Chemistry and Physics, Vol. 17/14, pp. 8681-8723, https://doi.org/10.5194/acp-17-8681-2017.
[4] OECD (2016), The Economic Consequences of Outdoor Air Pollution, OECD Publishing, Paris, https://dx.doi.org/10.1787/9789264257474-en.
[1] WHO (2005), WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide, http://apps.who.int/iris/bitstream/handle/10665/69477/WHO_SDE_PHE_OEH_06.02_eng.pdf;jsessionid=DFDA9BAE204770F4BA4490E3A309C33A?sequence=1 (accessed on 8 December 2020).
Notes
← 1. The emission projections presented in this section and used in this report rely on the GAINS model’s scenarios developed for the European Union-funded Action on Black Carbon in the Arctic (Klimont et al., forthcoming[9]). These scenarios provide a consistent framework to assess emission projections. The country-specific emission projections used might differ from projections developed individually by each country (see Box 2.1, Chapter 2).
← 2. All emission reductions in this section are calculated with reference to 2013 levels, unless otherwise specified.
← 3. This result is specific to the simulations produced for this report. Other assessments might lead to different results. Specifically, this result differs from the projected emission reductions submitted by individual Arctic Council countries to the Expert Group on Black Carbon and Methane (EGBCM), as reported in the 2019 EGBCM Summary of Progress and Recommendations (Arctic Council, 2019[10]). According to the EGBCM’s report, Arctic Council countries are projected to achieve a 23% reduction by 2025, assuming no change in emissions from Russia since 2013. Russia has not submitted individual projections, which makes it difficult to assess progress on BC emission reductions.
← 4. In the 2015 and 2017 national reporting, all Arctic Council countries have some level of BC emission data available. However, Russia only reported BC emissions to the Arctic Council in 2015 and has not provided BC inventory data to the Convention on Long-Range Transboundary Air Pollution. The absence of routine reporting by Russia represents a particularly significant gap in monitoring BC emissions that directly affect the Arctic (AMAP, 2019[8]). Nevertheless, there are independent BC emission inventories for Arctic Council and Observer countries, such as the GAINS model emission estimates used in this report. These include source- and region-specific technology characteristics (Klimont et al., 2017[11]).
← 5. Urban areas are visible as the red areas in Figure 3.4, Panel A.
← 6. These concentration levels cannot be compared directly to the WHO’s Air Quality Guidelines (100 µg/m3) as the guidelines are relative to a daily average, and not to a seasonal average. This is because, while there is evidence of the effect of peak exposure to ground-level ozone on health, there is not enough evidence on the effects of long-term exposure, which would justify using a yearly average (WHO, 2005[1]).
← 7. Mortality figures presented in this report include deaths due to stroke; ischaemic heart disease; tracheal, bronchus and lung cancer; chronic obstructive pulmonary disease; diabetes mellitus type 2; and lower respiratory infections resulting from exposure to PM2.5 concentrations only.
← 8. See Annex B for the methodology for calculating air pollution-related mortality.
← 9. This report focuses on a subset of health impacts that can be quantified at the global level. These include chronic bronchitis in adults, acute bronchitis and asthma symptoms in children, lost workdays, restricted activity days and hospital admissions. Other illnesses (e.g. impacts on fertility and birth weight) could not be quantified. See Annex B for the methodology for calculating the morbidity impacts of air pollution.