Climate Change Bill [HL]

My Lords, the reason we focused both in the Joint Committee and here today on aviation rather than on shipping is twofold: it is partly because shipping is much more complicated for attribution than the already complicated aviation sector, and partly, and largely implicitly, because aviation was thought to be a more important source as well as a more rapidly growing one. Work in the past couple of weeks has reappraised that and suggests what many have long suspected: that shipping may be twice the volume. Recognising that these are the early stages of a journey in five-year steps to 2050, is the noble Lord, Lord Rooker, satisfied that the Bill, as we are framing it, has flexibility so that we can deal with these things as and when both the international system and the greater knowledge and wisdom about how to include them make it possible?