While the usual image of greenhouse gas pollution is a billowing smokestack pushing out carbon dioxide, livestock passing wind contribute a surprisingly high percentage of total emissions in some countries.

• 说到二氧化碳等温室气体的排放，人们脑中通常会出现一个大烟囱冒出滚滚浓烟的画面。但在一些国家，牲畜放的屁在温室气体排放总量中所占的比例十分惊人。