此外，在20世纪，能源的消耗增加了16倍，导致每年1600万吨的二氧化硫排放到大气之中 — — 比自然排放量的2倍多。
Moreover, energy use has grown 16-fold during the twentieth century, causing 160 million tons of atmospheric sulfur-dioxide emissions per year – more than twice the total of natural emissions.