Work From Home (WFH) and other gimmicks cannot clear Jakarta’s air

For blue skies, tackle all major sources of pollution

🇮🇩 Versi Bahasa Indonesia tersedia di bawah

By Lauri Myllyvirta, Lead Analyst, CREA; Hubert Thieriot, Data Lead, CREA; Katherine Hasan, Analyst, CREA

Jakarta, Indonesia, by David Kristianto on Unsplash


CREA’s analysis of Jakarta air pollution data between 2020 to 2023 highlights that the city’s high air pollution levels are a result of emissions from several key emitting sectors: power plants, industry, transportation and open burning. The air pollution is a mix of local emissions taking place within the city, and long-range transportation of pollutants from neighbouring provinces. This means that Jakarta needs a regional action plan tackling all major emitting sectors, not a gimmick targeted at a very small part of the problem.

CREA compared air pollution levels during the years when commuting and driving were down dramatically due to COVID-19. Analysis of the data shows that there was no detectable drop in air pollution levels during COVID-19 lockdowns. Another piece of evidence revealing that commuting and driving are not major contributors to Jakarta’s air pollution is that Jakarta’s congestion falls by an average of 45% from Saturday to Sunday, but PM2.5 pollution levels only fall by 4%. This result might be counter-intuitive, but it can be explained by a few factors. Transportation is far from being the only source of Jakarta’s air pollution. Furthermore, transport includes trucks, buses and other vehicles not affected much by Work From Home (WFH) policy or weekday-weekend patterns. Much of the transport sector emissions affecting Jakarta are coming from outside of the city, have travelled long distances due to meteorological conditions and remain airborne for long periods of time.

Excessive focus on local use of private vehicles and two-wheelers in Jakarta appears to be a way for the Ministry of Environment and Forestry (MOEF) to distract attention from its failure to tackle the major sources of pollution systematically at the regional level. The Ministry has put significant efforts into downplaying the contribution of coal-fired power plants to the recent pollution episodes. For instance, in a recent media briefing, an analysis of a single coal power plant that is downwind of Jakarta during the dry season was presented by the Ministry’s representative, to make the case that coal power does not have much contribution to the air pollution problem. The analysis completely and deliberately neglected multiple large coal power plants that are upwind of Jakarta during the dry season.A detailed modelling exercise covering the period of July to August 2023 shows that hourly air pollution levels were correlated with plumes of different coal power plants reaching Jakarta, clearly showing the contribution of the power sector and the corresponding emissions taking place outside the Jakarta Metropolitan Area (Jabodetabek) to the pollution levels within Jakarta. During individual days, the contribution of coal power varied from 5% to 31% of the PM2.5 pollution.

Persistent high air pollution levels in Jabodetabek

Jakarta’s air pollution has reached some of the highest levels in recent weeks. The PM2.5 trend over the past five years shows a repeating pattern of high pollution periods, from May to September. As shown in Figure 1 below, levels varied significantly, with values around 35 μg/m3, which would be considered unhealthy for sensitive groups, and even beyond 50 μg/m3, unhealthy for the general public’s health.

Source: AirNow. Value represents the average of Jakarta South and Jakarta Central stations

Figure 1: PM2.5 24-hour concentration in Jakarta from 2020 to 2023

Monthly averages of PM2.5 levels from January 2020 to August 2023 do not show meaningful improvements. Pollution levels remain consistently high, where on average, PM2.5 levels range from 7 to 9 times higher than the WHO 2021 Air Quality Guideline for the annual PM2.5 recommendation level (μg/m3), at around 40 μg/m3 in high pollution months (May to September), and remains within unhealthy levels between 5.4 to 6.4 times higher than the 2021 WHO threshold, at 30 μg/m3 in the remaining months (October to April).

Figure 2: PM2.5 24-hour concentration in Jakarta by month in 2020-2023

The daily PM2.5 trend throughout 2023 is illustrated in Figure 3 below, showcasing that the citizens of Jakarta have already been exposed to PM2.5 levels from 25 to 45 μg/m3, which are considered moderate for the general public’s health and unhealthy for sensitive groups, leading up to the recent high pollution episode, and are expected to continue to face severe health risks from exposure to unhealthy levels beyond the WHO 2021 PM2.5 24-hour Interim Target 2 at 50 μg/m3 at least for the next month.

Figure 3: PM2.5 24-hour concentration in Jakarta in 2023. 

Note: The guideline values shown apply to 24-hour average concentrations and should not be exceeded in more than four days per year. The WHO guideline for annual average PM2.5 concentration is 5 µg/m3.

Transboundary pollution contribution to air quality in Jabodetabek

MOEF data quotes emissions within city limits, not considering emissions dispersion and contribution from outside Jakarta. Analysing emissions within the wider area, using 200 km as an illustrative radius, reveals that there are a few key sources: power plants, transportation, industry and open burning. Open burning includes both waste burning and agricultural residue burning. In addition, forest fires even further away from Jakarta occasionally contribute in a very significant way.Most importantly, PM2.5 pollution in Jakarta is not only caused by PM2.5 emissions, but also emissions of other pollutants that are transformed into PM2.5 particles in the air, such as SO2 and NOx. The power sector is the dominant source of SO2 emissions, while transportation is the largest source of NOx emissions, followed by the power and industrial sectors. Biomass and waste burning is the largest source of PM emissions, followed by transportation. Shown in Figure 4, biomass is separated into agriculture, commercial and residential, and together with waste burning, make up 47% of PM emissions.

Source: CREA analysis of the Community Emissions Data System (CEDS) emission inventory data for 2019.

Figure 4: Shares of PM, SO2, and NOx emission sources in Jakarta and the surrounding areas within 200 km radius

Coal power, one contributor among others

Jakarta is surrounded by a dozen large coal power plants within a distance of 100 kilometres. CREA has modelled the contribution of coal power plants around Jakarta using the HYSPLIT model, which is able to use near-real-time weather data, enabling the assessment of the sources of air pollution episodes as they happen. The hourly ambient PM2.5 measurements of the U.S. Embassy monitoring station in Central Jakarta has shown a strong correlation to the modelled coal power plant plumes reaching the location1.

1. p-value < 1e-15, R-squared 30%. HYSPLIT was run with 1-degree GDAS meteorological data. Emission, stack and location data for the coal power plants was taken from CREA & IESR collaboration work. Since HYSPLIT does not model chemical transformations or plume rise, simplified approaches were used. The contribution SO2 and NOx emissions to PM2.5 concentrations was calculated using a conversion rate of 20% and 30%, respectively, based on average values from more detailed CALPUFF modelling carried out for CREA & IESR collaboration work, and effective release height was calculated from stack height, stack diameter, flue gas temperature and velocity using Holland’s formula. Only particles underneath 10 metres were assumed to affect ambient levels.

Source: CREA analysis, AirNow.

Figure 5: Trend of PM2.5 measurement from U.S. Embassy Central Jakarta station against the modelled coal power plant emissions (Jul-Aug 2023)

The estimated contribution of coal power emissions to daily PM2.5 concentrations measured in Central Jakarta between July and August 2023 has varied between 2 to 12 µg/m3, at an average of 4 µg/m3. The share of coal power in total PM2.5 levels can be estimated at 5 to 31%, with an average contribution of 9%. Individual coal power plants with the largest average contribution to pollution levels in Jakarta over this period were Indramayu, Cilacap, and Cikarang Babelan.

Source: CREA analysis.

Figure 6: Estimates of coal power plant contribution to Jakarta Metropolitan Area PM2.5 levels (Jul-Aug 2023)

Earlier research by CREA found that pollution from coal power plants within 100 km of the city are responsible for about 2,500 air pollution-related premature deaths per year in Jakarta, costing IDR 5.1 trillion per year. Recent analysis done by CREA and Institute for Essential Services Reform (IESR) quantifies the magnitude of annual deaths linked to air pollution from coal power generation at the provincial level. Jakarta is ranked at the fourth highest nationwide at over 1,600 annual deaths (95% CI: 991–2,634), with the immediate neighbouring provinces of West Java (Jawa Barat) being the most affected province nationwide with over 4,000 annual deaths (95% CI: 2,566–6,438), and Banten with around 2,000 annual deaths (95% CI: 1,308–3,406).

Source: CREA analysis.

Figure 7: Top 10 provinces of Indonesia that are most affected by coal power emissions

Role of vehicles is grossly exaggerated — COVID-19 data reveals WFH will not solve Jakarta’s air pollution issue

The reduction in traffic volumes during COVID-19 and WFH was intuitively believed to decrease air pollution in Jakarta; however, the data shows that the WFH policy did little, if anything to reduce PM2.5 levels. Despite periods of WFH and large-scale social restrictions (pembatasan sosial berskala besar, PSBB) policies that were implemented between 2020 to 2022, there is no guarantee that transportation mobility in Jakarta will be reduced by current-day WFH policies, as shown in rising average congestion levels as well as increased visits to workplaces, parks, and recreational facilities. The U.S. Embassy’s Central and South Jakarta monitoring stations data for PM2.5 show little direct correlation. The average congestion levels in the January-July period increased by 47% from 2021 to 2023, based on TomTom traffic index, but yet average PM2.5 levels fell both in Central and South Jakarta. Analysing pollution levels during different days of the week does show a small impact from traffic volumes. Congestion drops 45% from Saturday to Sunday, but PM2.5 pollution levels only fall by 4% both in Central and Southern Jakarta.

Source: CREA analysis based on based on AirNow air quality monitoring data, and TomTom traffic index.

Figure 8: Comparison of PM2.5  average and congestion level in Jakarta by year (top) and weekday (bottom) (Jan-Jul period, 2021-2023)

Based on Google Mobility Report data, work trips increased 23% from 2020 to 2022, while trips to malls and other shopping and recreation locations increased by 32%, and trips to parks doubled. Yet, average PM2.5 levels fell by 14% and 20% in South and Central Jakarta, respectively.

Source: CREA analysis based on AirNow air quality monitoring data and Google Mobility Report.

Figure 9: Comparison of PM2.5  annual average and mobility trends in Jakarta (2020-2022)

CREA also previously conducted an analysis to identify changes in air quality during COVID-19 pandemic lockdowns across Southeast Asia. The analysis examined NO2 levels using Sentinel-5P satellite data to identify how the individual lockdown responses to COVID-19 impacted air quality. The images were generated using each nation’s specific lockdown start date, and were compared to the same time period in 2019. Where data was available, changes in PM2.5 or PM10 were also examined. 

On 12 March 2020, the WFH mandate was declared in Jakarta. On 30 March 2020, the government declared a public health emergency, whereby regional administrations were able to impose stricter social restrictions, like closing schools, workplaces, and limiting religious gatherings. With the WFH in place, Jakarta saw approximately a 40% drop in NO2 levels in comparison to 2019 levels, indicating a dramatic fall in urban emissions as economic and social activities in the city were reduced.

Source: CREA analysis based on Sentinel-5P satellite data.

Figure 10: Greater Jakarta and Banten region NO2 levels from March 12 to May 5, 2020 (left) and 2019 (right)

On the other hand, PM2.5 levels remained consistent with previous years, showing that the city’s ambient air pollution problem is greatly impacted by pollutants from surrounding areas. A closer look at air mass trajectories arriving in Jakarta when PM2.5 levels peaked at both of the U.S. Embassy’s Central and South Jakarta air quality monitoring stations, shows that much of the pollution during the episode was carried from coal into the city.

Electric vehicles (EVs) can be a solution: Yes, but… 

Power generation on Java-Bali is not just heavily coal-based, but the coal power plants are exceptionally highly polluting due to the lack of any emission controls for the most harmful pollutants. As a result, driving an electric vehicle (EV) charged with the current average grid electricity in Java-Bali will produce a much greater amount of SO2 emissions, slightly more PM emissions and a similar amount of NOx emissions as an average new gasoline vehicle2

2.  Assumptions: Gasoline vehicle at 140 gCO2/km, complying with EURO4 emission standards. SO2 emissions calculated based on Indonesia’s fuel quality standards. Java-Bali power mix was taken as 70% coal and 19% gas, and it was assumed that both coal and gas power plants meet their respective national emission standards. See spreadsheet with full calculations.

This is not a reason to hold off on transitioning to EVs, but it is a reason to speed up cleaning up the grid. Transitioning to clean power generation and transitioning to electric vehicles both take time, so it is essential to start both transitions immediately. Without a transition to clean power generation, switching to EVs will only move emissions from one place to another, not eliminate them.

Source: CREA analysis.

Figure 11: Emissions comparison between EV and gasoline-powered cars

Moving forward

Regulation and monitoring of ambient air quality and pollution from the major sources is key in protecting Indonesian citizens’ right to clean air. The policies must be properly enforced, ensuring transparency and accountability among all stakeholders involved. While considerable efforts have been made by the Government on air pollution control, further reforms are still much needed to establish a robust air quality governance. 

Policy recommendations

Revision of the National Ambient Air Quality Standard must be considered to trigger nationwide actions. In economies where air pollution has been successfully addressed, there is a time-bound target that must be set nationwide, to be met in all regions. Before setting such thresholds, it is essential for the Government to ensure pollution sources are well quantified, as well as their extent of contribution. A comprehensive source apportionment study would not only serve as the basis to determine key contributors, but also to better understand air quality dynamics as a result of local emissions, regional transport, and dispersion.

Actions to address air pollution must be taken on the regional level, including sources outside Jakarta and other major cities, in order to address transboundary pollution. Despite Jakarta’s efforts to set stricter controls on air pollution sources, emissions from outer Jakarta have a large contribution over Jakarta’s air quality and public health. Working with neighbouring jurisdictions and the national government to monitor and reduce pollution outside city borders will ensure that efforts in one municipality are not undermined by lack of effective pollution reduction elsewhere.

Enforcement of the updated 2019 emissions standards should be pursued for all planned thermal power plants, including ones currently under construction, to ensure that plants can still be retrofitted to fit stricter and safer emissions standards. Installation of Continuous Emission Monitoring Systems (CEMS) in all relevant facilities for all major pollutants (PM2.5, PM10, SO2, NOx, O3, and CO) should be pursued as part of compliance requirements. Real-time and time-averaged emissions reporting systems that can be easily accessed by the public will serve as a tool to help understand the air quality issues, and will become an asset for regulators and monitoring bodies to formulate and enforce evidence-based policies.

Emissions standards for polluting sectors should be based on sector-specific Best Available Technology to minimise their environmental and health impacts. This includes transportation as well as industrial sectors. Monitoring and enforcement of emission standards needs to be improved so that emitters have a strong incentive to comply.