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. Likewise, more nitrogen fertilizer is applied in agriculture than is fixed naturally in all terrestrial ecosystems, and nitric-oxide production from the burning of fossil fuels and biomass also surpasses natural emissions.
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。氮肥料也大量运用在自然生态系统中。由于化石生物的燃烧而产生的一氧化氮也超过了自然界释放的总量。