| Name | Scope | Year | Description |
| Technology Action Plan | Nationwide | 2013 | Bridges Cambodia’s climate technology gaps to enhance climate action under the Kyoto Protocol. |
| National Cooling Action Plan (NCAP) | Nationwide | 2022 | Targets emission reductions from refrigeration and air conditioning, part of Cambodia’s NDC. |
Overview
Cambodia has experienced rapid economic growth due to increased industrial activities and urbanization, but this development has also led to rising air pollution levels. The industrial sector accounted for 32.8% of the national GDP in 2018, driven by increasing fuel consumption, coal usage, and thermal power investments. Urban expansion has resulted in a growing number of vehicles, further contributing to poor air quality. As a result, all major air pollutants have increased, with the annual mean PM2.5 exposure at 22 µg/m3, which is 4.4 times the WHO guideline of 5 µg/m3. In 2019, air pollution was responsible for 3,499 deaths (21 per 100,000 people), with stroke (9%), ischemic heart disease (7%), and chronic obstructive pulmonary disease (7%) being the primary causes.
The annual mean concentrations of O3 and PM 2.5 derived for the year 2014 for the whole country were 28.08 ppb and 23.6 μg/m3, respectively. Air quality data from Phnom Penh in 2018 showed an average PM2.5 level of 19.26 µg/m3, within Cambodia’s national air quality standard of 25 µg/m3. The observed SO2 annual average concentration was 1.3ppb in 2017, which also complied with the Cambodian standard of 38.17ppb (100 μg/m3). Monthly mean PM2.5 concentrations in Cambodia across multiple years exhibit a distinct seasonal trend. Average PM2.5 levels peak during the winter months (December to February), often exceeding 50 µg/m³, and significantly decrease during the mid-year months (April to September), dropping to around 10 µg/m³. Regarding the maximum variability in PM2.5 by month over the years, PM2.5 concentrations show high variability during the winter months, frequently spiking well above the mean values, while the mid-year months have lower, more stable pollution levels.
Cambodia’s greenhouse gas (GHG) emissions have surged by 285% between 1994 and 2016, reaching 163,592 Gg CO2-equivalent in 2016. The main gas emitted in terms of GHG contribution remains CO2, driven by the large contribution of the FOLU sector to national emissions, followed by methane (CH4), nitrous oxide (N2O), and hydrofluorocarbon HFC (UNCC, 2020). The Forestry and Other Land Use (FOLU) sector is the largest contributor to emissions, mainly due to deforestation, followed by methane (CH4), nitrous oxide (N2O), and hydrofluorocarbons (HFCs). In 2020, total emissions of particulate matter, ammonia, and nitrogen oxides reached 160 Mt, 114 Mt, and 158 Mt, respectively. The primary contributors were residential cooking, agriculture, and transport, indicating that pollution sources are deeply intertwined with daily life and economic activities.
Yearly mean PM2.5 levels in major cities of Cambodia show moderate air pollution, with Paoy Paet consistently recording the highest concentrations, exceeding 30 µg/m³ in most years. Serei Saophoan, Battambang, and Siem Reap show similar trends, fluctuating between 20-30 µg/m³, while Phnom Penh maintains the lowest levels, generally around 18-25 µg/m³. Although PM2.5 levels are lower than in many neighboring countries, all cities remain above the WHO standard, indicating ongoing air quality concerns linked to urbanization, vehicular emissions, and regional pollution sources.
Recognizing the link between air pollution and climate change, Cambodia has integrated short-lived climate pollutants (SLCPs) control into the Clean Air Plan for Cambodia 2021. This plan emphasizes reducing emissions from industrial activities, improving air quality monitoring, and controlling deforestation-related emissions. Given the country’s heavy reliance on coal and ongoing urban expansion, ensuring the effective implementation of these policies will be critical for both public health and environmental sustainability.
Action Plans
Air Quality Standards
Policies