Indonesia's high population and rapid industrialization present serious environmental issues, which are often given a lower priority due to high poverty levels and weak, under-resourced governance.[109] Issues include large-scale deforestation (much of it illegal) and related wildfires causing heavy smog over parts of western Indonesia, Malaysia and Singapore; over-exploitation of marine resources; and environmental problems associated with rapid urbanization and economic development, including air pollution, traffic congestion, garbage management, and reliable water and waste water services.[109] Deforestation and the destruction of peatlands make Indonesia the world's third largest emitter of greenhouse gases.[110] Habitat destruction threatens the survival of indigenous and endemic species, including 140 species of mammals identified by the World Conservation Union (IUCN) as threatened, and 15 identified as critically endangered, including Bali Starling,[111] Sumatran Orangutan,[112] and Javan Rhinoceros.[111] Much of Indonesia's deforestation is caused by forest clearing for the palm oil Industry, which has cleared 18 million hectares of forest for palm oil expansion. Palm oil expansion requires land reallocation as well as changes to the local and natural ecosystems. Palm oil expansion can generate wealth for local communities if done right. If down wrong it can degrade ecosystems and cause social conflicts.[113]