真相是每多一个儿童也许意味着90年的二氧化碳配方（主要来自他在一生中所消费的产生排放的产品和公用设施 ） ， 最多不过今天的水平 — — 大约没人每年15吨。
The truth is that one extra child means perhaps 90 years of CO2 emissions (caused largely by a lifetime of consuming products and utilities that account for such emissions), which at worst would remain at around today’s level of about 15 tons per person annually.