Most fires in Indonesia have been raging since July, and the most intense fire spots have happened around September to October. The reasons of burning are divided into two reasons which are naturally caused, and human-caused
NATURALLY-CAUSED
Indonesia is located in the area called “Maritime continent” which is the name given to the region of Southeast Asia consisting of Indonesia, Philippines, and Papua New Guinea. It is located within a warm ocean region known as the tropical warm pool; a region associated with large scale variations in the climate system. The Maritime continent is the key driver of atmospheric circulation because of its enormous ability to transfer heat to the air. It is the most thermal energized area on the planet so it causes the atmosphere of that region to have more heat that leads to fire problems in the tropic.
Climate change has been a key factor in increasing the risk and extent of wildfires. Although, wildfires risk depends on a number of factors; temperature, soil moisture, the trees, and other potential fuel, all these factors involve climate variations both directly and indirectly. Climate change and weather influence warmer, and drier conditions which contribute to the spread of fires and boost the wildfire risks. There are three weather ingredients that can affect wildfires; Temperature, Wind patterns, and Moisture.
Temperature affects the sparking of forest fires by allowing fuels to ignite and burn faster if it gets warmer. The sticks and trees which are natural fuel receive radiant heat from the sun, which heats and dries potential fuels. Temperature also triggers the frequency of lightning strikes which are generated by warmer temperature that causes the atmosphere to create more convection systems. Hotter and drier conditions also accidentally the cause of human-caused fire.
Wind probably has the biggest impacts on a wildfire and it is also the most unpredictable factor. According to Dr. Terry Clark, senior scientist at the National Center for Atmospheric Research, his research claimed that not only wind affects how the fire develops, but also how the fire itself develops wind patterns. If the fire can create its own weather patterns, it means that the patterns can affect the way fire spreads. The stronger the wind blows, the fire spreads. Wind can also change the direction of the fire, so even if the peat fire burns on the ground and below the surface, it can rise up into the trees, and cause Crown fire as well.
Moisture, in the form of humidity, and precipitation can reduce the intensity of fire since potential fuel is difficult to ignite when moisture can absorb the fire’s heat. When the air is covered with moisture, it releases the moisture in the form of rain, or precipitation which has a direct impact on fire prevention.
In 2015, Indonesia suffered from massive forest fires due to the El Nino event that caused the altering weather patterns. The result of this transformation was a change in rainfall pattern in Indonesia. The length and severity of the fire season in Indonesia strongly depended on the amount of rainfall during the dry season. According to the satellite observations captured by Global Precipitation measurement (GPM), the rain fell in Northern Sumatra, and Malaysia; while, almost none fell in Southern Sumatra, and Kalimantan. The precipitation was low enough for fires to spread; along with, the dry season seasonal fires.
The peat soil itself is also a fuel for the ignition of the fires. In tropical areas such as Kalimantan, peat is one of the reasons the fires have spread due to the components and structures of it. Peat is formed from generations of dead and partially decaying organic matter. The vegetations and trees fall and are buried, and then it is incorporated into layers of soil without entirely decomposing. Therefore, peatland can permanently lock away carbon which is a natural fuel that prones to Smouldering combustion.
The most extraordinary feature of peat soil is its high porosity, which facilitates water movement; therefore, the forest floor is continuously saturated with water. Naturally, peatland is wet, so it does not cause fire; however, when the peat soil is drained, it will increase the acceleration of carbon mineralization which causes a higher bulk density, and lower porosity, hinders the freedom of water movement. It can be said that peat soil eventually hardens into coal which is extremely flammable, and when combining to the dry season, the fire has spread further and it is difficult to stop.
Peatlands are the largest natural terrestrial carbon store and very essential to tackle climate change. When they are burned, they contribute about 10% of greenhouse gas emissions which Carbon dioxide are estimated at 1.3 gigatonnes. For the fire in peat swamp forest in Indonesia in 2015, the burning released nearly 16 million tonnes of Carbon dioxide a day. The large amount of carbon that has been released influences the changes in climate, and climate change increases the risk of forest fires, creating the loop between them.
HUMAN-CAUSED
Farming in Lake Sentarum, West Kalimantan in Indonesia. How are global development practitioners helping local communities in Indonesia achieve sustainable economic and social development while fighting climate change? Photo by: Tim Cronin / Center for International Forestry Research / CC BY-NC-ND
On the other hand, human-caused fires can be due to any number of reasons. In the case of Kalimantan, there is the illegal practice of clearing the land referred to as “Slash-and-Burn”. Under the practice, farmers burn agricultural and logging debris to prepare the land for new plantations of oil palm. They drain squishy peatlands before setting them on fire, as mentioned before, when peatlands are dried, it means that their watery protection is gone because the compaction of soil obstructs the water motion.
Slash-and-Burn is arguably the easiest way to clear the land. Using the Slash-and-Burn process is much faster and in some cases, it is cheaper, at least in the short run. The farmers also consider this practice helping the disposal of any disease that might have affected the plantation. However, Slash-and-Burn is also considered to be a crude deforestation and “a crime against community” called by the government.
BURNING ACTIVITY AND
ILLEGAL LAND OWNERSTIP TRANSFORMATION
The root of the problem might start from the problem of legal land rights of some small communities. 75% of Indonesia’s land is classified as “State forest land”; nevertheless, some smaller farming communities often live on these lands which are open-access properties, but they live there without legal rights, and always get intimidated by the authority figures. The main drivers of forest fires are land-clearing practices by smallholder farmers for palm oil plantations and the interplay of elite interests (Purnomo et al.2016)