Open waste burning is a widespread practice that is provoked by a lack of systematic waste collection, the unavailability of other disposal options, and inadequate land for the final disposal of the collected waste, especially in low- and middle-income countries. From a global perspective, two billion people have no waste collection at all, and the waste of over three billion people is either dumped or subjected to uncontrolled burning. Currently, an estimated 620 million tons of waste annually is openly burned. The open burning of waste releases various toxic pollutants into the air, soil, and water, ultimately impacting food and human health. Raising awareness and capacity building regarding the seriousness of the environment and health impacts of waste burning is the key to stopping it and promoting alternative treatment options for reducing black carbon emissions and other toxic substances. However, we lack quantitative-assessment-based results to support policy and decision making regarding the climate impact of BC emissions due to open burning. Therefore, CCET–IGES conducted a study on open waste burning in three representative cities in developing Asia: the city of Padang in Indonesia, the city of Bago in Myanmar, and the municipality of Steung Saen in Cambodia. According to the study results, 20%, 17.5%, and 2% of the generated waste stayed at the source as uncollected waste in Padang in Indonesia, Steung Saen in Cambodia, and Bago in Cambodia, respectively. The estimated average amounts of waste burning in Padang, Steung Saen, and Bago amounted to 75.8, 7.5, and 2.1 tonnes/day, respectively. Out of the three study locations, the highest percentage of generated waste was burned in Steung Saen in Cambodia (21%), followed by Padang in Indonesia (11.5%), and Bago in Myanmar (2.1%).
According to the assessment results, the highest per capita waste-burning rate was in Steung Saen in Cambodia (0.127 kg/capita/day), followed by Padang in Indonesia (0.077 kg/capita/day), and Bago in Myanmar (0.009 kg/capita/day). The overall climate impact that resulted from the BC emissions per tonne of waste burned in Padang, Steung Saen, and Bago amounted to 3,056, 1,746, and 1,279 kg CO2-eq/tonne of waste burned, respectively, which indicates the substantial impact that BC emissions have on climate change. According to the literature, the climate impact from primitive disposal practices, such as open dumping or nonsanitary landfilling, ranged from 500 to 1,000 kg CO2-eq/tonne. The climate impacts caused by the BC emissions per tonne of waste burned in all three locations were higher than the GHG emissions from primitive disposal practices. Regarding the source of waste burning, 95% of the waste burned in Padang occurs at the household level, and the final disposal sites were the key source of the waste burning in the other two cities. Considering the magnitude of climate impact from BC from different sources in the pilot cities, the regulations, policies and actions for mitigating open waste burning should give more priority to household level in Padang whereas for the Bago and Steung Saen, the priority should be given to the final disposal site. The results of this study could increase awareness and capacity development at the municipality level on the severe impact of open burning on climate change. Implementing certain measures, such as compost pits at the household level to reduce the burning of food and garden waste in backyards, and the promotion of waste-sorting programs for recycling at commercial centres and institutions, are vital steps to be followed in the short term. The creation of integrated solid-waste-management systems that improve the waste collection at the municipality level is a key strategy to be implemented for reducing the occurrence of waste-pile burning and its hazards in streets or public places.