A meta-analysis of 69 such studies suggests a point estimate of the limit to be 7.7 billion people, while lower and upper meta-bounds for current technology are estimated as 0.65 and 98 billion people, respectively.
综合69份元研究显示预估数值为77亿人，依目前的技术来看最低和最高估算分别为6.5亿和98亿。