The Earth's next mass extinction -- the first caused by people -- is on the horizon. And the consequences are almost unthinkably dire: Three-quarters of species could disappear.
원문출처 : http://www.cnn.com/2016/10/27/opinions/sutter-wwf-sixth-extinction/index.html
원문출처 : http://www.cnn.com/2016/10/27/opinions/sutter-wwf-sixth-extinction/index.html