Recent research suggests that fires started by Asian farmers in order to clear land for palm oil production may have contributed over 30% of the increase in global atmospheric CO2.
Palm oil has become the most widely produced edible oil in the world, with more than 30 million metric tons produced in Malaysia and Indonesia alone, the two countries now supplying more than 85 percent of global demand. However, the environmental effects have been significant.
In the last decade, Asian farmers have cleared tens of thousands of square miles of forests to accommodate the demand for palm oil. As a result, the land is vulnerable to fires, which are now more frequent, and are having a serious impact on the air as well as the land. The clearing often occurs in drained peatlands – peat material in Borneo, for example, stores the equivalent of about nine years worth of global fossil fuel emissions.
Until recently, scientists knew little about what drives changes in how fires spread and how long they burn. NASA-sponsored researchers have used satellites to make the first series of estimates of carbon dioxide (CO2) emitted from these fires – both wildfires and fires started by people – in Malaysia, Indonesia, Borneo, and Papua New Guinea.
Jim Collatz, an Earth scientist at NASA’s Goddard Space flight Center in Greenbelt, Maryland, along with lead author Guido van der Werf of Vrije University, Amsterdam and others, sought to estimate the emissions since the devastating 1997-98 fires, and to analyze the interplay between the fires and drought. Presented in December 2008 in Proceedings of the National Academy of Sciences they found that seasonal fires from 2000 to 2006 doubled the amount of carbon dioxide (CO2) released from the Earth to the atmosphere above the region.
Carbon monoxide in fire emissions are related to the amount of carbon dioxide, so they used the carbon monoxide detecting Measurements of Pollution in the Troposphere (MOPITT) instrument on NASAs Terra satellite,Terra’s Moderate Resolution Imaging Spectradiometer (MODIS) and Landsat 7 to compare the emissions from peat land with forest, as well as 1997-2006 fire data and research computer models,
Previously, scientists found that wildfire emissions rose during dry El Niño seasons. During the severe El Niño of 1997-1998, fire emissions from this region comprised 15 percent of global fossil fuel emissions and about 30 percent of the global atmospheric increase over that period.”This link between drought and emissions should be of concern to all of us,” said co-author Ruth DeFries, an ecologist at Columbia University in New York. “If drought becomes more frequent with climate change, we can expect more fires. In this part of Asia, human-ignited forest and peat fires are emitting excessive carbon into the atmosphere.”
“Indonesia has become the third largest greenhouse gas emitter after the United States and China, due primarily to these fire emissions,” Collatz said. “With an extended dry season, the peat surface dries out, catches fire, and the lack of rainfall can keep the fires going for months.”
The agricultural fires and related wildfires also ravage delicate ecosystems in conservation hotspots like the western Pacific island of Borneo. Regional air quality is effected to such a degree that schools and airports have to close out of concern for public health and safety. Peat fires also aggravate air pollution problems in this region because they release four times more carbon monoxide than forest fires.
While local economic benefits may accrue from palm oil production, there are significant local and global ecological effects of the methods of production which need to be considered.