Various measures are proposed as targets to avoid climate change, though that is a misnomer. The climate is changing. It always is. The goals and targets are really ‘point of no return’ markers, representations of when we lose control. After we pass those points, we can only mitigate, not reverse, the change. Unfortunately, we don’t know exactly what those numbers are, or whether we’ve already passed them. Conservatism would suggest immediate action. Debate and a search for consensus may uncover less conservative numbers – too late. Have we reached the point of no return? It may be best to assume so.