I first heard of this term from my supervisor when he talked about climate change mitigation and adaptation measures. In fact, it has been largely used in climate change work such as in IPCC or CSIRO reports. However, I personally think that it is an infeasible term (if you know what I mean, that’s we can theoretically define it, but we will never find it in reality -So what’s the point of using the term in practical decision-making?). I found that WWF did not use the term elsewhere, and now I know why :D. Interesting. We will come back to this topic soon.