El Niño Drives Indonesia Peat Fires Toward 2015 Emission Levels by Early September 2026

Indonesia's 2026 fire season opened with 946 MODIS-VIIRS hotspots on August 31, concentrated in Kalimantan and Sumatra peatlands dried by 90 percent rainfall deficit. Underground combustion at low temperatures evades surface detection while emitting three times the fine particulate matter and twice the methane of canopy fires, according to emission factors derived from the 2015 event. Satellite algorithms miss sub-canopy and smoke-obscured burns, undercounting the persistent subsurface fraction that continues until October-November rains.

The 2015 analog released 1.75 billion tons CO2-equivalent over three months; current output already equals 10 percent of that total after one month. Positive IOD reinforcement of El Niño dryness matches the 1997 and 2015 patterns that produced regional haze crises affecting millions and accelerating peat carbon loss equivalent to years of national fossil emissions. Real-time Global Fire Weather Database forecasts correctly anticipated the uptick, yet lack subsurface thermal or gas-flux constraints.

Without expanded LiDAR or ground-penetrating radar integration into SiPongi, policy responses will continue to target visible flames rather than the months-long smoldering reservoir. Rains may extinguish surface activity, but carbon already volatilized will persist in the atmosphere for centuries.

Field's team projects total 2026 emissions could reach 1.2 billion tons if October rainfall remains below the 2015 threshold, locking in another record year for tropical peat carbon release.