Mark Ellingham has made a sizeable fortune from the creation of the Rough Guides to almost everywhere. He is shortlisted for the Royal Society's prize for science writing, for his book The Rough Guide to Climate Change. Now, in a conversion that would command the admiration of St Paul, he declares that "binge flying" constitutes a huge threat to the global environment. "If the travel industry rosily goes ahead as it is doing, ignoring the effect that carbon emissions from flying are having on climate change, we are putting ourselves in a very similar position to the tobacco industry." He readily admits the irony that he, of all people, should articulate such a warning. He appeals for moderation, for setting some limits on our insatiable appetite for travel: "We now live in a society where, if people have nothing to do on a Saturday night, they go to Budapest for 48 hours. We fly anywhere at the slightest opportunity, 10 times and upwards a year. This needs to be addressed with the greatest urgency." Environmentalists would say that Ellingham is stating the obvious, adding of course that it is pretty rich coming from him. I am full of admiration for his frankness, however. Almost all of us are hypocrites about climate change. We know that it is real, and desperately serious. Yet we are in a shocking muddle about how to relate our personal behaviour to the phenomenon. For those who inhabit the developed world, opportunities for travel represent the