临界点警告
Overall, 20% of the Amazon rainforest has been "transformed" (deforested) and another 6% has been "highly degraded", causing Amazon Watch to warn that the Amazonia is in the midst of a tipping point crisis.
总体而言，亚马逊雨林已有 20% 被「改造」（砍伐），另有 6% 受到「严重退化」，导致亚马逊观察组织警告称亚马逊地区正面临临界点危机。
生态系统临界点是指：当环境压力累积到一定程度后，生态系统会发生突然、不可逆的结构性转变，即从一种稳定状态跃迁到另一种状态。