Consequences

Brexit has occupied 25,000 civil servants in the UK for several years, as well as, presumably at least thousands of civil servants in the EU for several years. It will continue to occupy a large fraction of UK government resources for many years to come.

So: that's effort that isn't going into the enormous changes which would need to be made if we wanted to avoid seriously catastrophic global warming. Which we are not, of course, going to avoid.

Oh well, who really cares if billions die and our children's lives are blighted: what is that compared to the momentary glory of Boris Johnson?