This work, which was published in "Nature," late 2009, after a number of years of analysis, led to the final proposition that we can only find nine planetary boundaries with which, under active stewardship, would allow ourselves to have a safe operating space.
在2009年底，“自然”杂志上发表的这个项目 ， 经过数年的分析， 终于得出最后的提议， 那就是我们只能够找到 九个地球界限 在积极领导下， 可能允许我们自己有个安全的工作空间。