A resurgence of haze caused by forest and peatland fires in Indonesia has once again affected several ASEAN member states, highlighting ongoing challenges in regional environmental cooperation. In early September, thick smoke from these fires spread as far as the southern Philippines and significantly reduced visibility at Supadio Airport in Pontianak, Indonesia, to approximately 100 meters, preventing the landing of aircraft carrying Indonesia’s forestry minister. Since August, the ASEAN Specialised Meteorological Centre (ASMC) has issued its highest alert level, Level 3, due to numerous detected hotspots across Sumatra and Kalimantan.

In response to the transboundary haze, Malaysia has requested permission from Indonesia to conduct cloud seeding over Indonesian territory, while Singapore has issued daily haze advisories to assist the public in planning activities and events. Despite these measures, the recurrence of haze episodes reflects a persistent problem in the region.

Since the late 1990s, ASEAN has developed various mechanisms to address transboundary haze. The Regional Haze Action Plan was introduced in 1997, focusing on prevention, mitigation, and monitoring. This was followed by the adoption of the ASEAN Agreement on Transboundary Haze Pollution (AATHP) in 2002, the bloc’s first legally binding treaty on the issue. The ASMC plays a key role in monitoring hotspots, weather conditions, and smoke movements, while the AATHP provides a framework for cooperation, joint response, and assistance when fires escalate.

However, the recurrence of haze raises questions about ASEAN’s effectiveness in tackling a problem that primarily originates and affects its own members. Unlike regional challenges involving external actors—such as water security in the Mekong River where China, a non-member, plays a significant role—haze pollution largely stems from actions within ASEAN countries themselves, mainly Indonesia. This dynamic exposes a tension within ASEAN’s principles: while haze pollution crosses borders, the root causes are often tied to national land use policies, plantation licensing, forest management, and law enforcement, which remain under individual member states’ jurisdiction.

ASEAN’s principle of non-interference helps maintain cooperation across diverse political systems but limits how far the bloc can intervene in national matters. Furthermore, while ASEAN entities such as the ASMC can detect and monitor fires, attribution of legal responsibility requires detailed land concession data, investigations, and enforcement measures that reside within national authority.

Singapore has sought to address this gap through its Transboundary Haze Pollution Act, which allows legal action against entities whose activities outside Singapore contribute to haze pollution within its territory. The law, used notably during the severe haze of 2015, focuses on prevention and deterrence by targeting agribusiness and pulp-and-paper companies. Nonetheless, critics note that even with such measures, enforcement effectiveness depends on access to information and cooperation from the source country.

Corporate accountability presents additional complexities. Large plantation companies operating across forest and peatland areas may not be held responsible for fires near their concessions without transparent concession mapping, reliable fire monitoring linked to specific land parcels, and credible investigations capable of tracing the cause to a corporate actor rather than smallholders. These investigative and enforcement functions remain national responsibilities, outside ASEAN’s direct control.

Experts stress that forest and peatland fires are difficult to prevent, especially as climate change intensifies dry periods. While climate factors exacerbate risks, human activities and institutional capacities play crucial roles in fire occurrences.

Looking ahead, ASEAN’s ability to manage transboundary haze will depend on translating existing frameworks into more effective actions. This includes establishing common response protocols, ensuring compatibility of communication and data systems, conducting joint exercises among disaster-management agencies, and agreeing on procedures for sharing information, equipment, and personnel across borders during major fire events. Enhancing these practical measures could improve the region’s preparedness before the next haze crisis emerges and further test ASEAN’s credibility as a regional institution.