Sentence:  Since the mid-1980s, when Indonesia first began to clear its bountiful forests on an industrial scale in favour of lucrative palm-oil plantations, “<WSD>haze</WSD>” has become an almost annual occurrence in South-East Asia. 
Meaning of the word marked with <WSD> tags:  Very fine solid particles (smoke, dust) or liquid droplets (moisture) suspended in the air, slightly limiting visibility.