KUALA LUMPUR: Emerging hotspots in Kalimantan could signal a rising risk of transboundary haze, but experts say it is too early to attribute the deteriorating air quality solely to the developing El Nino phenomenon.
Universiti Sains Malaysia atmospheric physicist Assoc Prof Dr Yusri Yusup explained that while open burning and dry weather are key drivers, prevailing wind patterns will ultimately determine the spread of smoke from fires across Borneo.
“Fires are largely triggered by human activities such as uncontrolled open burning, though natural causes cannot be ruled out,” Dr Yusri said on Tuesday (Aug 11). “When uncontrolled burning occurs during a dry spell, fires spread easily across parched vegetation. We must analyse the fire sources, weather conditions, and wind direction before assessing their full impact on air quality.”
While earlier projections suggested El Nino would peak around August or September, Dr Yusri noted that revised forecasts indicate its peak may be delayed until later in the year.
“This delay doesn't mean El Nino isn't happening; its strongest impact may simply arrive later than expected,” he said. “Consequently, we cannot immediately blame current hotspots on El Nino. We must monitor how the phenomenon evolves over the coming months.”
Geographical features and shifting monsoon phases also complicate air quality predictions. With the southwest monsoon winding down in late August and the transitional monsoon phase approaching in September and October, variable wind directions make it difficult to forecast smoke trajectories.
“Geography plays a critical role. Mountain ranges influence rainfall, wind movement, and pollutant transport,” Dr Yusri added, stressing that early monitoring and fire prevention are essential to prevent a severe haze crisis.
The warning comes as air quality in Sarawak degrades, with eight areas recording "unhealthy" Air Pollutant Index (API) levels as of noon on Tuesday.
Kota Samarahan recorded the highest API reading at 169, followed closely by Kuching (165), Bintulu (159), Samalaju (155), Mukah (154), Sibu (154), Simanggang (154), and Sarikei (153).
Sarawak Premier Tan Sri Abang Johari Openg urged the public to take precautions, noting that while the current haze is not as severe as past episodes, the risks associated with El Niño remain a concern.
Residents have been advised to follow Sarawak Disaster Management Centre guidelines, which mandate halting all outdoor activities if API levels reach the "very unhealthy" threshold of 200 or above.
