Climate Change Bill [HL]

My Lords, I do not think I was here when this matter was discussed in Committee, but surely the phrase ““pre-industrial levels”” is unacceptably vague and imprecise in any Act of Parliament. What exactly does it mean? I assume that it means pre the industrial revolution, which took place over an extremely extended period of decades or even centuries in different countries at different times. Indeed, it has not been going for very long in India and China, so I ask the noble Lord to explain, if he can, precisely what ““pre-industrial levels”” is meant to mean.