Indonesian forest or plantation fires occur yearly mostly on peat lands and peat-swamp forest (PSF) in the dry season and are worse in drier years. While mostly caused by intentional land clearing for commercial purposes, the fires are strongly influenced by the El Niño Southern Oscillation (ENSO). In El Niño years, dry-season rainfall can be less than half of normal Severe El Niño events have long been associated with large scale fires for e.g. 1997, 2006. (Field et al, 2009)
The high carbon content of peat means peat fires release vast amounts of smoke and carbon. Tropical peatland fires emit more than 300 million gram of carbon per hectare, compared to 7.5-70 million gram of carbon per hectare from other habitat types (Cochrane, 2003).
The most severe Indonesian forest fire recorded in history happened in 1997 in Borneo (Kalimantan) and Sumatra. According to Page et al, 2002, during the severe 1997 El Niño, fires destroyed approximately 8 million hectares of Indonesian Forest (In comparison, Singapore’s land area is 70,000 hectares) and released 810-2,570 million tonnes of carbon into the atmosphere which constituted 13 to 40% of mean annual global carbon emissions.
Forest fires have adverse effects on people, flora, fauna and their habitats. Health problems among people have been reported in areas affected by haze produced from the fires which include most parts of Indonesia and neighbouring countries such as Brunei, Malaysia, Singapore and Thailand. Economic and material losses caused by the fires stand at the billions of USD. Furthermore, forest fires are often cited as one of the primary reasons for the decimation of protected animal and plant species in Indonesia.
Effects on the Climate
• Global warming –The massive carbon emissions from peat fires makes them a major contributor to the global increase in atmospheric CO2. The Kyoto Protocol, to which Indonesia is a signatory, obliges ratifying countries to reduce CO2 emissions by $5% of 1990 levels by 2012. Based on the findings of Hooijer et al (2006), eliminating Indonesian peatland fires completely would achieve this in one fell swoop.
• Reduced light intensity – Smoke blocks out the sun, reducing light intensity. Sunlight intensity can decline by up to 92% under thick smoke conditions, negatively influencing plant photosynthesis rates (Davies and Unam, 1999) and possibly reducing food security in the region.
• Potential influence on El Nino South Oscillation (ENSO) – ENSO has far-reaching effects on world climate. The frequency of El Niño events is thought to have increased since the mid-1970s, due to global warming (Trenberth and Hoar, 1997). This could create a positive-feedback loop: increased burning increases atmospheric CO2 concentrations, which raises temperatures, and increases the frequency and severity of ENSO events, thereby increasing the incidence and severity of future fires, etc.
How does it affect me? Am I somehow responsible for it? The next post on the Haze, Forest Fires and Me will discuss this.