Southeast Asian haze.

The Southeast Asian haze is the visible air pollution affecting many countries in Southeast Asia, caused mainly by fires set as part of slash-and-burn agriculture. The large-scale phenomenon has been observed annually since at least the early 1970s, especially during the dry season, but certain years, including 1997, 2013, 2015, and 2019 have seen particularly dense pollution. In 2015, the haze affected Singapore, Brunei, Indonesia, and Malaysia, and had secondary effects on Thailand and the Philippines. Some researchers believe that the haze also affects more distant nations. While the haze is connected to public health and economic problems, many people continue to use fire to clear space for crops because it is the cheapest and most readily available option. In an effort to prevent or limit the haze, national and international organizations are working to develop political and economic incentive structures for farmers to use other agricultural methods. Additionally, some countries have adopted laws that seek to punish or publicly shame those who continue to use fire to clear their lands.