Two beautiful volumes in a cloth-bound case reach me. They are Speeches and Articles by HRH The Prince of Wales 1968-2012, published by University of Wales Press. The explanatory list of abbreviations and acronyms alone gives a charming sense of the range of subjects covered — ‘Foot and Mouth Disease, Foreign Press Association, Forest Stewardship Council … Myalgic Encephalopathy, Member of Parliament … Non-Commissioned Officer … Not In My Back Yard! … Roundtable for Sustainable Palm Oil’. Among the many speeches on the environment, however, I cannot find his speech in Rio de Janeiro in March 2009, entitled ‘Less Than 100 Months To Act’. There Prince Charles warned that if we did not act by July 2017, ‘we risk catastrophic climate change’. Such change ‘calls into question humanity’s continued survival on the planet’. The world therefore had to reduce its CO2 emissions by that date, he said. Every year, at this season, this column has made it its solemn duty to keep this prediction before our eyes. Global CO2 emissions since 2009 have increased by over 2 per cent a year. So we’ve very nearly had it.

One of the many things David Cameron said when he thought he would not win the general election, and therefore would not be held to it, was that he would give up his party’s leadership before the next one. If he does so voluntarily, not forced out by defeat or jealous colleagues, it will be a great accomplishment of self-discipline. It should be rewarded by ending the stupid custom that has grown up in which the only way for an ex-prime minister is out. Mr Cameron would be an excellent Foreign Secretary in the manner of Alec Douglas-Home under Edward Heath.

The Living Wage is a perfect piece of cant. Even Boris Johnson, who usually has a nose for these things, has fallen for it (or perhaps he is only pretending). It is calculated by the Centre for Research in Social Policy at Loughborough University. The measure is ‘the basic cost of living’, which makes it £9.15 in London and £7.85 outside. It sounds humane, fair etc; and of course it is coercive too, because who wants to be seen to be against it? But the basic cost of living varies enormously according to who you are as well as where you are. It matters little if a young person living with parents, or an eager new immigrant from a poorer country, earns a very low wage in order to get a foot on the ladder, or if the second earner in a family wants pin money. It matters very much indeed for a 40-year-old sole breadwinner with three children. What the Living Wage clearly does — and this is the sneaky way in which it is ‘good for business’ — is that it favours large, established employers over new, small ones. HSBC, for instance, is a Living Wage ‘partner’ of the Greater London Authority (even as it cuts 8,000 jobs); the House of Lords is a recent sign-up. The partners can then capture all the business from public bodies and form a cartel against new entrants who cannot pay so much. Anyway, the amount of the wage at these levels makes little difference to the recipient, because of tax credits. If someone who earned £7 an hour now earns £8, he may gain as little as 15 pence because of the benefits lost. The beneficiary is the Treasury, which enjoys a reduced cost.

We think of petty nationalism as a form of devolution — government getting closer to the people. In fact, though, it is often a form of centralisation by the new statelet. The local counties and regions generally suffer. In Scotland, for example, there is now only one police force (Police Scotland) for the entire nation, a classic recipe for political control. The latest Scottish government scheme is to nationalise management of all the rivers. Until now, each river has been well run separately — by the people who own its banks. Now some authority in Edinburgh will lay down the law for all of them, proving, all too quickly, that salmon and Salmond cannot coexist.

My friend James Stourton is writing the authorised biography of Kenneth Clark, of Civilisation. He tells me of an interesting letter by K to his mother about his son Alan, later the MP and notorious diarist. Writing in 1945, when Alan was a schoolboy, Kenneth said Alan ‘has a good head … I think he would do well in politics if he weren’t — by profound conviction — a fascist. That will never do in this country, tho’ the rest of the world may ultimately require it.’ I think he was right about Alan’s fascism (though the man himself denied it, claiming he was a Nazi), and it confirms my theory that just as Kenneth wanted to expound civilisation, Alan wanted to do the same for barbarism. Where K pointed at the bust of Voltaire and exclaimed ‘He is smiling the smile of Reason’, Al would find the head of Ozymandias and say ‘Admire that wrinkled lip and sneer of cold command’. Barbarism would be a tremendous TV mega-series, covering the full sweep of history from Homeric times to Kim Jong-un and Simon Cowell. But who could best present it? I think Simon Sebag Montefiore and Andrew Roberts could (barbarously) fight it out.

Wandering through a Norfolk country churchyard on Saturday, we inspected the line of the most recent graves. Instead of depicting crosses on their stones, two showed footballs. Archaeologists often derive most of their knowledge of a lost civilisation from its funerary monuments. How will they decode these mysterious chequered spheres? Manichean representations of light and dark? Moon worship? Or will it work the other way round, so that in a couple of thousand years everyone will recognise a football and no one a crucifix? (The church, by the way, was a couple of miles from where Prince Charles’s young grandchildren reside. I have seldom seen a place looking less climatically catastrophic, and I fully believe that Princess Charlotte will live long enough to form the words ‘Lighten up, Grandad!’).