The Year the Sky Turned Brown: Lessons from the 1997-98 El Niño Haze Crisis — and Why They Matter for 2026-27

A Perfect Storm Brews

In early 1997, ocean temperatures in the eastern Pacific began climbing sharply. By mid-year, the world was watching the formation of what would become one of the strongest El Niño events of the 20th century. For most of the globe, this meant shifted rainfall patterns and disrupted seasons. For maritime Southeast Asia — Indonesia, Malaysia, Singapore, Brunei, and beyond — it meant something far more acute: the conditions for a regional environmental catastrophe.

El Niño suppresses rainfall across the western Pacific and Indonesian archipelago, turning the normally wet dry season into something closer to drought. In a region where land-clearing by fire is routine practice — particularly on Sumatra and in Kalimantan, Borneo — a drought year transforms a manageable agricultural tool into an uncontrollable hazard. Peatlands, which are normally waterlogged and fire-resistant, dry out and become a tinderbox. Once peat ignites, it doesn’t just burn on the surface; it smoulders underground for weeks or months, virtually impossible to extinguish with conventional firefighting.

1997-98 became the textbook case of how this combination — El Niño-driven drought plus land-clearing fires plus degraded peatland — can spiral into a transboundary disaster.

Timeline of the Crisis

Early-to-mid 1997: El Niño conditions strengthen rapidly in the Pacific, becoming one of the strongest on record up to that point. Across Indonesia, the dry season arrives earlier and lasts longer than normal, with rainfall deficits across Sumatra and Kalimantan.

July–October 1997: Fires set for land clearing — by smallholders, but notably also by commercial plantation and timber companies — escape control on a massive scale. From July to October 1997, ASEAN countries including Brunei Darussalam, Indonesia, Malaysia and Singapore were badly affected by the smoke haze from fires in Sumatra and Kalimantan. Smoke spreads across the region, with haze reported as far as Malaysia, Singapore, Brunei, Thailand, and the Philippines, even reaching westward toward Sri Lanka.

September 1997: As the crisis peaks, ASEAN environment ministers convene an emergency meeting in Indonesia. Indonesian President Suharto opens the meeting with an apology for the haze, but attributes it to natural causes rather than deliberate land-clearing for commercial purposes.

Late 1997 into 1998: The fires continue to burn through the dry season, compounded by the deepening Asian Financial Crisis, which hit Indonesia, Malaysia, Thailand, and other regional economies simultaneously. The haze crisis happened in the midst of the devastating Asian Financial Crisis, meaning countries in the region struggled to cope with this disaster on top of an economic meltdown.

April 1998: ASEAN environment ministers meet again in Brunei. Behind closed doors, ministers spoke candidly — though not publicly — about the need to punish the plantation companies responsible for igniting the fires.

Aftermath (1998 onward): By the time the rains finally returned, the scale of destruction became clear, and the diplomatic fallout shaped the next two decades of regional environmental policy.

How Bad Was It?

The numbers from 1997-98 remain staggering by any measure:

The fires burned through an enormous area — estimates range from around 45,000 square kilometres of forest in Kalimantan and Sumatra to broader assessments of more than 9 million hectares of land and forest destroyed across the region. The United Nations Environment Programme went so far as to label the event among the most damaging fire disasters in recorded history.

The economic toll was severe and wide-ranging. Total damages across the region were estimated at roughly $9 billion, with impacts spread across air and sea transport, tourism, construction, forestry, and agriculture. The crisis affected millions of people and disrupted transport, tourism, construction, forestry, and agriculture sectors across the region. A separate economic assessment focused specifically on haze-related damages put Indonesia’s losses alone at roughly one billion US dollars, with combined damages to Malaysia and Singapore at around 0.4 billion dollars.

The environmental cost extended far beyond the visible smoke. The event is estimated to have released between 1 and 2 billion tonnes of carbon — a contribution to global emissions on the scale of entire industrialized economies in a single year. Peatland destruction was central to this: ASEAN is home to 56% of the world’s tropical peatlands, and more than 3 million hectares of this peatland area has been destroyed by fire.

The Diplomatic Fallout

What made 1997-98 distinctive wasn’t just the physical scale — it was how it exposed the fragility of ASEAN’s “non-interference” doctrine when one member’s domestic land-use practices became another member’s public health emergency.

Singapore and Malaysia bore the brunt of imported haze without having lit a single fire, and public anger in both countries built quickly as air quality indices reached hazardous levels for weeks at a time. Indonesia, for its part, was navigating both the fires and the collapse of its currency and banking system, and was in no position to mount a rapid, well-resourced firefighting response. The tension between “this is our sovereign land-use issue” and “your smoke is in our lungs” became the defining friction of the crisis — and it has resurfaced in nearly every major haze episode since (2005, 2013, 2015), each time reviving the same accusations and the same diplomatic awkwardness. In a later episode, Indonesia accused Singapore of “behaving like a child” while simultaneously requesting significant financial assistance to fight the fires — a dynamic widely seen as illustrative of the unresolved tensions dating back to 1997-98.

The most concrete institutional outcome was the 1997 Regional Haze Action Plan (RHAP), ASEAN’s first coordinated framework for monitoring, prevention, and mitigation — though it carried no legal force. This was followed in 2002 by the more ambitious ASEAN Agreement on Transboundary Haze Pollution (AATHP), a legally binding treaty. Yet the gap between agreement and action proved wide: it took Indonesia 11 years after the treaty entered into force to ratify it, finally doing so in 2014, and even after ratification, national and local implementing regulations remained largely absent.

Lessons Learned

Several themes emerge clearly from 1997-98 and the haze crises that followed:

Drought conditions turn a normal practice into a hazard. Slash-and-burn land clearing is widespread and, in a normal-rainfall year, largely self-limiting. El Niño removes that natural check. Any preparedness framework needs to treat an incoming El Niño as a trigger for pre-emptive restrictions on burning, not a wait-and-see situation.

Peatland is the multiplier. The 1997-98 disaster wasn’t primarily about surface vegetation fires — it was about peat. Once peat dries and ignites, fires become deep, persistent, and almost impossible to extinguish without sustained rain. Peatland protection and rewetting programs are arguably the single highest-leverage intervention available between El Niño events.

Crises compound. The simultaneous arrival of the Asian Financial Crisis meant governments had neither the fiscal capacity nor the political bandwidth to mount an adequate response. Preparedness plans built only for “normal” economic conditions can fail precisely when they’re most needed.

Transboundary problems need transboundary accountability — but sovereignty concerns are real and persistent. The AATHP exists, but two decades of slow ratification and weak enforcement show that legal frameworks alone don’t solve a problem rooted in domestic land-use economics, corporate practices, and enforcement capacity at the local level.

Early warning works only if it’s acted on. By 1997, El Niño forecasting was already mature enough to provide months of lead time. The fires still happened at scale because warning systems weren’t connected to enforcement, resourcing, or cross-border coordination on the ground.

Looking Ahead: The 2026-27 El Niño

This history isn’t simply academic. NOAA’s Climate Prediction Center has issued an El Niño Advisory, with conditions present and expected to strengthen into the Northern Hemisphere winter of 2026-27. The numbers being discussed are notable: the eastern Pacific (Niño 1+2 region) is already running at +2.1°C, an anomaly described as fueling rapid development, and the CPC puts the odds of the event reaching strong or very strong intensity by October at roughly 65%. NOAA’s latest forecast gives a 63% chance of a very strong El Niño between November 2026 and January 2027, which would place it among the largest events in the historical record dating back to 1950.

Compounding this, forecasters are also tracking a likely positive Indian Ocean Dipole developing alongside El Niño — probabilities for a positive IOD phase rise from around 5% in May to over 80% by September 2026, while neutral conditions fall below 10%. The combination of these two patterns — sometimes called a “Double Lock” in regional climate communication — has historically been associated with the most severe drought and fire conditions across maritime Southeast Asia, since both phenomena independently suppress rainfall over Indonesia and intensify simultaneously.

If the current forecast trajectory holds, the underlying climate conditions for 2026-27 bear a real resemblance to those of 1997-98: a strong-to-very-strong El Niño, reinforced by a positive IOD, arriving with significant lead time before its peak impacts.

How the Region Can Be Better Prepared This Time

The good news is that 2026 is not 1997. Satellite fire-detection systems, ASEAN’s haze monitoring infrastructure, and national fire management agencies are all dramatically more capable than they were three decades ago. But capability only translates into outcomes if it’s deployed early and decisively:

Treat the forecast as an operational trigger, not background information. With high-confidence El Niño and positive IOD signals already months ahead of the typical dry-season peak, governments in Indonesia, Malaysia, and neighbouring countries have a real window to pre-position firefighting resources, issue early burning bans, and ramp up enforcement in known fire hotspots — particularly peatland-heavy areas of Sumatra and Kalimantan — before the dry season fully sets in.

Prioritize peatland rewetting and canal-blocking programs now. Restoring water tables in degraded peatland before the dry season begins is one of the most effective ways to reduce fire risk, and the lead time from current forecasts allows for targeted action in the highest-risk concessions and community areas.

Strengthen corporate accountability mechanisms. A recurring theme across 1997, 2005, 2013, and 2015 has been the role of commercial plantation operations in fire-related land clearing. Concession-level monitoring, satellite-based fire attribution, and enforcement against companies — not just smallholders — remains an area where implementation has historically lagged policy.

Activate cross-border coordination early, before tensions flare. Pre-agreed protocols for information sharing, joint monitoring, and resource-sharing (firefighting aircraft, personnel) reduce the chance that a crisis becomes a diplomatic dispute layered on top of an environmental one.

Prepare public health systems for sustained poor air quality. Hospitals and clinics in haze-prone areas should anticipate respiratory illness surges, and public communication about air quality index thresholds and protective measures (masks, indoor air filtration, school closures) should be ready to deploy quickly rather than improvised mid-crisis.

Build in economic resilience planning. One lesson from 1997-98 is that a haze crisis arriving during economic stress is far harder to manage. Given ongoing global economic uncertainty, contingency budgets for fire response shouldn’t be the first thing cut if other pressures emerge.

Closing Thought

The 1997-98 haze crisis became a defining moment for ASEAN environmental cooperation precisely because the region was caught without the tools, the agreements, or the political will to respond at the scale the disaster demanded. Nearly thirty years later, with a comparably strong El Niño — and a reinforcing positive IOD — now forecast for late 2026 into 2027, the question facing the region isn’t whether the climate conditions for a severe fire season could re-emerge. They appear to be assembling already. The question is whether the institutions, monitoring systems, and political coordination built in the decades since 1997-98 will be deployed early enough to make a difference this time.

Source: Claude A.I.