Extensive Land Clearing
First and the foremost cause can be extensive land clearance and cultivation in the neighboring country Indonesia which has a highly escalated deforestation. Illegal logging and the burning of forests to clear land for cultivation has made Indonesia, the world’s third largest emitter of greenhouse gases. Forest fires often destroy high capacity carbon sinks, including old-growth rainforest and peat lands.
In May 2010, Indonesia declared a moratorium on new logging contracts to help combat this. But still will remain a major cause for Singapore haze as long as burning will remain a preferred land-clearing method as it is quick and efficient, requiring minimal labour, enriches soils and acts as a default strategy in lieu of affordable alternatives.
Forest fires occurrences in the region of Malaysia & Indonesia have also polluted air quality to un-healthy levels, and being the major cause of haze in Singapore.