The COP26 summit is yet another reminder of the grim fate that awaits humanity if it does not get its act together on the climate. Gas-guzzling boilers? No more to be sold by 2035. Coal? Out by 2040. Log burners? Forget it.

As with everything that is unhealthy when it comes to food and drink, it seems that there is a conspiracy afoot to take all enjoyment out of life.

So thank goodness for the virtues of antiques. As I have often rehearsed in this column, furniture, silver, works of art and ceramics, among many other well-crafted and delightful treasures, tick every green box that can be thought of when it comes to saving the planet.

As the Antiques Are Green movement advises us: “Invest in the Future, Recycle the Past.”

And what an example this campaign gives us to prove its point, the humble Windsor chair, a thing of beauty and practicality: “The chair parts were made by craftsmen who lived in the woods where the materials came from,” AAG tells us. “The turnings were produced on treadle-operated lathes, then parts were taken on foot to a local workshop to be assembled. From there the completed chairs would be distributed around the country by horse and cart or waterways.”

Some of these chairs are now well into their second century of use and treasured as much now as when they were first made – arguably more so.

“By buying this chair to use again we have conserved our natural resources and prevented the carbon footprint of another chair being produced, that possibly would come all the way from the Far East,” says AAG. On the other hand, a new mass-produced chair will hit the waste tip long before the antique Windsor chair is sold again at auction, goes to the restorers and is revived and retailed again for another 40 years’ use.

If auctions are about anything, they are about history: making it, celebrating it, retelling stories.

As I have written many times before, objects that raise huge sums at auction often have little intrinsic value in themselves; a masterpiece by Francis Bacon is still no more than a collection of materials – oil paints, canvas and wooden frame – but the creative process, the resulting ‘art’, the proximity to genius and the historic associations that it has make it worth more than its weight in gold.

Ounce for ounce, nothing outside of digital art carries more value than rare stamps. Now one of the rarest – and arguably the most important ever printed – is up for sale.

The first Penny Black went on sale in 1840, revolutionising people’s ability to communicate with each other. Suddenly, anyone could send a letter from one end of the country to the other without the recipient having to pay for a bespoke mail service that excluded all but the wealthy.

The stamp on offer here is attached to what is known as the Wallace document, named after Robert Wallace, who headed up the commission on postal reform. The document is dated April 10, 1840 and the Penny Black became valid postal tender almost four weeks later on May 6.

A simple and inexpensive process coupled with the iconic design of the Queen’s head, Rowland Hill’s ground-breaking concept became a worldwide phenomenon adopted by every country.

Developing the system and service to support that idea was rather more complex, but it is still in place today.

What have you got on your wall? I thought about this last week when I heard of the sale of artworks that had been hanging on the wall of a Las Vegas hotel. They were not just any old daubs, mind you, but nine pictures and two ceramic artworks by arguably the most important artist of the 20^th century: Pablo Picasso.

Hung on the restaurant wall of the Bellagio Hotel, the artworks spanned more than 50 years of Picasso’s career, with the top price among them coming for the 1938 painting Woman in a Red-Orange Beret. Expected to fetch $20m-30m, it sold for a very encouraging $40.5m.

In fact, as a whole the consignment did rather better than hoped, totalling $110m.

That’s quite a wallful.

It reminded me, too, of the first great discovery on the Antiques Roadshow. Back in 1986, a couple in Barnstaple, Devon decided to show a painting that they had owned since 1930 to art expert Peter Nahum, one of the show’s specialists. They hadn’t thought it worth anything but were curious to find out more about it and, anyway, were taking their dog for a walk so thought they might as well drop in on the show which was filming in the town.

It transpired that it was the most important missing work by the Victorian artist Richard Dadd and dated to about 1845 – two years after he had killed his father in a mad frenzy. Titled The Halt in the Desert, it was painted while Dadd was detained in Broadmoor and shows a rather peaceful moonlit scene. The British Museum bought it for a large six-figure sum.

So now we know: a work of art can be worth far more once you destroy it. Well that’s true if you’re Banksy. Just a few weeks ago I mused on how much his ‘transformed picture’ Love is in the bin – previously Girl with Balloon – might make when it appeared at Sotheby’s on October 14. It had previously sold for £1m in 2018, and the moment the hammer fell, the canvas dropped through a shredder hidden in the bottom of the frame.

Shocking it may have been at the time, but it was a stunt that caught the art market’s attention, fascination and even admiration, turning the picture immediately into Banksy’s most famous / notorious artwork, and so also the most valuable of his paintings.

It remains the greatest irony that the artist who does more than any other to subvert the art market and its processes has proved himself yet again the ultimate master of the industry’s marketing machine.

In this context, while Sotheby’s estimate of £4-6 million might have looked a little punchy, it did not seem beyond the bounds of possibility. So what happened on the night? Forget the estimate; frenzied bidding took the painting to £18.5 million hammer, a record for any piece of Street art, sealing Banksy’s status at the top of the international art pantheon for living artists alongside the likes of David Hockney, Ed Ruscha, Beeple and Jeff Koons.