Tremendous academic debate has ensued after the Stop Ecocide Foundation’s 2021 proposal to amend the Rome Statute in such a way that a new “fifth” international crime of “ecocide” would be included. This discourse has largely focused on problems with defining the crime, the practical challenges of its international acceptance, and whether international criminal law is even the appropriate avenue to address its concerns. What has received less attention is the implications of this potential recognition over other regimes of international law. This post inquires into one such emerging question, namely the question of whether the “responsibility to protect” (R2P) civilian populations from mass atrocities could be invoked in the context of environmental exigencies. In other words, this post explores an “environment-oriented R2P” that, if accepted, could justify the use of force. “Mass atrocities” under the existing R2P cover three of the four crimes already mentioned in the Rome Statute; the fourth crime is “aggression”, which would nevertheless justify States responding with force in self-defence.