Southeast Asia’s mountain burning triggers Yunnan cross-border haze

On May 26, mountain-burning activities in Myanmar and Laos caused PM2.5 concentrations in Yunnan’s border areas to soar to 15 times international standards, with visibility of less than 500 meters in Pu’er and Xishuangbanna. Satellite monitoring shows that the average number of fires in Southeast Asia is nearly 2,000 per day, and smoke is transmitted across the border through a “pollutant corridor”, which will reduce Yunnan Pu’er tea production by 8% in the spring of 2025, with a direct loss of more than 200 million yuan. China and ASEAN are establishing a cross-border fire point monitoring system through the Lancang-Mekong cooperation mechanism, but regional coordination and law enforcement capacity still needs to be improved.