The Kyoto Protocol will only go into effect if the combined volume of CO2 emissions of the signatory countries exceeds 55 % of the world total. The US is the single largest producer of greenhouse gases, accounting for 36 % in 1990. Last year President Bush created a huge controversy when he announced that he opposed the Kyoto Protocol.
由於京都議定書約定，簽約的附件一國家二氧化碳排放量至少要達到百分之五十五以上，公約才能生效，而美國是全球溫室氣體排放最大國，一九九○年的排放量已佔全球四分之一，去年布希總統上任後卻宣布暫不履行議定書，致使各國譁然。