“During the late 1970s, Borneo changed from being highly fire-resistant to highly fire-prone during drought years,” according to Robert Field, an atmospheric physicist from the University of Toronto. He attributed the abrupt change to rapid increases in deforestation and population growth.
The forest ecosystem was destabilised, Field said, by humans clearing trees for farming. It became drier and more vulnerable to future drought. Droughts, usually during El Niño years in the Pacific Ocean, have triggered huge fires in Indonesia seven times since 1960. The worst blazes were in 1997 and 1998, creating smog in cities hundreds of kilometres away — and at least one plane crash.
The biggest source of smoke and carbon-dioxide emissions during south-east Asian forest fires is the burning of peat in the deep swamps on which many forests grow, said Field. His findings add to growing concern about Indonesia’s decision earlier this month to end a two-year moratorium on turning peatlands into oil-palm and other tree plantations.
See full story