An immense human toll

100,000 deaths, 500,000 rendered ill and a damage of around $16 billion to the Indonesian economy - that is the outcome of illegal slash-and-burn activities in Indonesia in 2015.

While the economic damage and the number of people falling sick have long been known, the figure of 100,000 deaths comes from a recent study conducted jointly by Harvard and Columbia universities in the US. First author Shannon Koplitz and collaborators used atmospheric modeling along with data made available by satellites to find out how many people lost their lives last year on account of the fires.

Health expert Jonathan Buonocore, who studied the effect of air pollution on human health, told DW: "If we know, what the contribution of air pollution there is from the fires, and we know what the fires do to health we can then calculate what the health burden of the fires is."

Deadly particulates

Miriam Marlier, a researcher at the Department of Ecology, Evolution, and Environmental Biology at Columbia University in New York, also took part in the study to determine how much fine particulate matter was released into the atmosphere in 2015 as a consequence of the fires.

Fine particulate matter PM10 and PM2.5 are particles smaller than 10 or 2.5 microns. Marlier says: "What makes it unique in equatorial Asia is that we have very intense fires located close to a densely populated region." Over 150 million people are living in countries like Indonesia, Malaysia and Singapore that are the most affected.

The impact of particulates on the health of the millions of affected citizens is well researched, says Buonocore. The tiny particles enter the lungs and cause respiratory problems such as asthma and, in some cases, even lung cancer. They can also result in heart attacks and brain strokes.

"Our study concluded that there were about 100,000 deaths due to the fires in the region in 2015. Out of them, 91,600 were in Indonesia, 6,500 in Malaysia and 2,200 in Singapore," Buonocore said, although no direct causality could be established between the fires and particular deaths.

Fire despite warnings

The devastating conclusions show that appropriate measures were not taken at the right time to prevent such fires, says Robert Field, an atmospheric scientist at NASA's Goddard Institute.

"There was a substantial fire-fighting and mitigation response in 2015, which, from what I can tell, was different from previous episodes. But I think it was a response to the crisis rather than to the forecast. Judging by the forecasts, we knew already in May or June that the El Niño was going to be quite strong, and that drying would be severe by August in the fire-prone regions of Sumatra and Kalimantan," Field told DW, adding that it would have been much more useful had Indonesia deployed all the personnel in July to engage in prevention activities rather than tapping them in September to fight the fires.

Experts say preventive measures are key to resolving the problem. That's because a significant proportion of the fires in Indonesia involves peat fires. According to World Bank data, almost a third of the 2.6 million hectares of land burnt in 2015 in Indonesia was of peatland.

Peat is organic matter, which when dry is very flammable. Peat soils can be many meters thick. And only the upper layers of the peat are dry and typically about 20 centimeters below the surface the peat is quite humid. However, the fires spread underground through the root systems of trees that have been slashed or toppled. This dries out the surrounding peat, which ignites and the fires spread, ending up with slow-burning wet material and that produces heavy smoke. Peat fires are therefore hard to put out or control.

David Gaveau of the Center for International Forestry Research (CIFOR) who was not part of the study, says: "When peat fires become large they can be put out only by rain. Peat fires are the ones that produce heavy smoke and cause a lot of problems both locally and across Southeast Asia."

Corruption and mismanagement

There are various reasons behind the Indonesian government's inability to prevent the fires despite warnings. A major problem involves the ineffective enforcement of laws to prevent fires in provinces and islands.

An incident that occurred this year serves as a good example of this problem. A team from the Ministry of Environment and Forestry on the island of Sumatra was attacked during this year's fire season by a huge mob, which threatened to burn them alive.

The investigators were freed only after the government deployed heavily armed police. Indonesia's Environment Minister Siti Nurbaya Bakar condemned the incident, saying it highlighted how companies form murky alliances with local communities to burn land and protect their plantations, the AFP news agency reported.

"Local corruption certainly played a big role," said an Indonesian expert on condition of anonymity.

The problem is compounded by the fact that Indonesia remains an agricultural country where a significant chunk of the population relies on farming for survival. But, over time agricultural land became scarce and therefore the less fertile peatlands are increasingly being brought under cultivation. "Population pressure is an important factor," said another analyst.

Furthermore, many point to Indonesia's poor land allocation practices for causing the fires. For instance, they note, lands that need to be protected are either partially opened for agriculture or exploited without permission. "The whole land management is chaotic and it requires to be fixed," an expert pointed out.

A tough fight

The current Indonesian government is taking measures to prevent fires, observers say. "The Ministry of Environment and Forestry, other ministries, and the president are serious in their efforts to prevent fires," said CIFOR's Gaveau.

"They know that the harmful fires are happening on degraded peatlands. The Indonesian government established a peatland restoration agency to restore this degraded land," he underlined. They also established the One Map Policy to resolve overlapping land claims.

"However, no one really knows how to restore these degraded lands. It will be like a big experiment. It may take years, but nations should really give the Indonesian government credit for attempting this."

Another way to prevent fires and save lives is by strengthening preventive measures, stresses NASA physicist Field. "One short term thing which needs to be put in place is a basic early warning system for these drought conditions."

The recent study conducted by Field shows that the risk of fires increases dramatically should precipitation per day remains less than 4 mm for an extended period of time.

The Indonesian Agency for Meteorology, Climatology and Geophysics also operates a very effective system for identifying dangerously dry conditions. Such conditions can be anticipated in Indonesia because of the strong El Niño influence, the expert said, adding that it's then up to the government to introduce appropriate measures for the troubled regions.

A failure to take such measures could increase the damage and lead to an uptick in the number of fires, Field said, warning that it would have devastating consequences not only for Indonesia and the region, but worldwide as they would contribute to a spike in global green house gas emissions.

"In that case the conservative estimate in 1997 was the emissions represented 13 percent of mean annual global fossil fuel emissions. And that's the low end of the estimate."