Eleven weeks, nearly a season
In 1997 the fires put out just over 800 million tonnes, and the bar rounds down. The dashed line converts Indonesia's fossil emissions for one whole year into carbon. Turned into carbon dioxide, this season's 76 is about 8.7% of India's yearly output.
In plain terms Each bar is one fire season's carbon. The dashed line is a whole year of Indonesia's fossil fuel.Source · Carbon Brief fire emissions analysis, to 7 September 2026
Area is the wrong measure
Eleven weeks of burning have nearly matched a normal full season. We usually size a fire by the land it covered.
What most people think
A fire season is as bad as the area it burned.
What the data shows
24.8cm
On peat it is not area that matters. It is depth.
Burned area reached 286,000 hectares by late August 2026. Depth is measured on the ground, not from orbit.
In plain terms Two panels: on the left what most people assume, on the right what the numbers show, with the one figure that settles it.Source · Mongabay, to 24 August 2026
One province is carrying the season
So depth is the measure nobody collects from orbit. What everyone sees instead is where the smoke goes.
Of the 48,889 hectares burned by then, West Kalimantan carried 28,680. Each pin sits on a provincial capital and stands for a province, not a fire.
In plain terms A flat world map. Shaded countries are the ones the haze reaches. The pins are Indonesia's six priority peat provinces.Source · Mongabay and Nusantara Atlas, 9 August 2026
What peat actually is
The map shows smoke crossing five borders from one set of provinces. Three words first.
- Peat
- Plant matter that fell into water and never fully rotted. Waterlogged, it piles up century after century.
- Smouldering
- Burning without flame. Slow, low and underground. It can run for weeks and survive rain.
- Water table
- How far down you dig before you hit water. Canals push it down, and dry peat burns.
Source · WRI, Yale Climate Connections
The fire took 24.8 centimetres
Peat is wet ground that burns once it dries. Novita, a peat researcher, explains: "Unlike fires in dry ecosystems, peat fires can smolder underground, so the soil itself becomes readily available fuel."
How to read this — Read this column as distance downward. The top mark is ground level, and every mark below is how far under your feet that line sits.
24.8 centimetres, the average across Indonesia's peatland, is about a school ruler taken off the top of the ground. Canals run 50 to 75 centimetres deep and the column draws the shallow end. The peat below can run past 20 metres.
In plain terms Each mark is a depth below ground, not a layer of time.Source · Kiely 2019, Yokelson 2022, Mongabay, WRI
Drain it, dry it, burn it
The fire ate 24.8 centimetres of ground that is meant to stay waterlogged. The water leaves like a bathtub with the plug pulled.
Peat is waterlogged, so plantations drain it. The law allows 40 cm. Oil palm takes it to 50 or 75.
Dry peat is fuel. Thousands of years of stored plant matter with the water taken out.
Surface fuel lights first, then the peat smoulders downward. In October 2015 it took 24.8 cm.
Source · Mongabay, WRI, Kiely 2019, Yokelson 2022
All four end in the same place
That sequence runs every dry season. Now set it beside three other carbon flows. Three are converted from carbon dioxide to carbon first, so the widths compare directly. India's band is the widest, and Indonesia's own is a fraction.
How to read this — Follow each band from left to right. All four end in the atmosphere, and a band's width is million tonnes of carbon a year.
Three of the four bands convert carbon dioxide into carbon, multiplying by 12 over 44. India's band is its own fossil emissions on that arithmetic. The 2015 fires alone came to about 38% of India's yearly carbon dioxide.
In plain terms Each band is one source of carbon. Thicker bands carry more.Source · Carbon Brief, WRI, Our World in Data
The agency ended, the canals stayed
One bad season put out more carbon than Indonesia burns for power and transport in a year. But a body once existed to put the water back.
The 2026 season is the first full fire season since 2016 with no national body mandated to re-wet peat.
In plain terms The key events in order down a rail, with coloured dots flagging the pivotal moments.Source · Mongabay, Kiely et al., Carbon Brief
Lungs, charges, and a quiet leak
The canals are still there, so the smoke reaches clinics before it reaches any dataset. By 4 September the worst-hit provinces had reported 50,891 cases of acute respiratory infection, which means an infection of the nose, throat or lungs. By late August, 72 people had been charged.
Now take the fire away. Drained peat sits in the air and rots, so that alone puts about 72 million tonnes of carbon into the atmosphere every year. Picture a tap left running in an empty house, and the bill still arrives.
Source · Mongabay and WRI, to 4 September 2026
Smoke fills the clinics, 72 people are charged, and drained peat leaks carbon all year without any fire.