I am on the shores of Lake Geneva, at Switzerland's Arvinis wine fair, where the wines of Bergerac are the guests of honour. 

Since the Bruno novels wax lyrical about the merits of these wines, I was invited along to help promote these splendid wines, and so I made considerable use of R L Stevenson's phrase that "wine is bottled poetry" and Victor Hugo's great line that "God made water, but man made wine." (Some of the best Bergerac wine-makers are women, like Amelie Montfort, Nicole Maury, Patricia Atkinson, Katherina Mowinckel and Caro Feely.) 

A highpoint was a splendid dinner with Karl-Friedrich Scheufele and his wife Christine, who run the Chopard watch business and the Bacchus vinotheques in Switzerland, and have each read all the Bruno books. They recently bought Chateau Monestier la Tour, which dates back to the 12th century, and are producing terrific wines and using their Chopard marketing expertise to help promote Bergerac wines in Switzerland and Germany. 

Two more of my favourite Bergerac vineyards were also there: Chateau les Tours des Verdots, where David Fourtout makes spectacularly elegant wines, and Chateau Thenac, whose white wines have to among the best in south-western France.

My turn to cook for the diner des celibataires, when the women all go off to bingo and the men gather alone and we take turns to cook. 

I'm preparing a soup of beans based on the carcass of a duck, followed by an avocado pear stuffed with shrimps and my home-made mayonnaise. Then I'm serving Boeuf Perigourdin, which is like Boeuf Bourgignon except I use Pecharmant rather than Burgundy wine and I add a glass of my own home-made vin de noix. Then winter salad, cheese and I'm making tarte aux pommes except that I marinaded the apples (from my own trees) in calvados overnight. 

The wines will almost all come from my friends Sean and Caro Feely at Chateau Haut Garrigue in Saussignac, who only make bio-dynamic wines. I will start with their version of champagne, and then their Semillon blanc, followed by their 2007 Merlot for the beef. For the apple tart, I'm thinking of a 2005 Loupiac but I may be tempted away by a rather good Monbazillac. Choices, choices...

Chateau les Merles, a very fine hotel with golf course and an excellent restaurant just outside Bergerac, is celebrating the coming of Christmas with an advent calendar that offers presents each day to the lucky person whose email is drawn by lot.

Day one is three bottles of excellent wine, so good luck to those taking part!

To take part, click here.

September so far has been unusually hot in the Perigord and the winemakers are crossing their fingers that the sunshine lasts through the rest of the month, which should mean an excellent vintage this year. 

The cold spring and rains in June and early July had worried them, but while the harvest will be late, it should be very good indeed. The one great fear is the storms that usually come with the equinox around September 21. 

My Green friends are also worrying, because more and more winemakers in the region are going bio and avoiding pesticides and chemical treatments. But if we get heavy rains later this month and not enough wind and sun to dry the grapes, they fear that an outbreak mildew of mildew could provoke an anti-bio backlash. And while sulphur dust in limited quantities is approved for organic farmers, they prefer to use something more bio. 

Some are experimenting with diluted milk as a preventive and others are using a solution of water and garlic. Put one whole bulb of garlic in a litre of water with a few drops of liquid soap for a day, then strain it and dilute in with ten times as much water and spray. It works in our vegetable garden.

This week I visited Sean and Caro Feely at their vineyard in Saussignac, which is in the process of being renamed Chateau feely (it used to be Chateau Hair Garrigue). 

It is not easy to find from the map offered by the Maison de Vin, but worth the effort. Take the D14 road from Bergerac to Ste Foy la Grande and take a left on the D4 to Saussignac, and after 400 metres there is a sign on the left for Chateau Haut Garrigue. 

They have a spectacular view over the Dordogne valley, and after visiting the vineyards and hearing Sean explain the bio-organic methods they use to keep the terroir healthy, we sat in the open air to taste their various wines. 

I was accompanied by my friend and neighbour Raymond, a retired officer of gendarmes and a great lover of wine. We came away with three cases, one of their wines called Sincerite, all Sauvignon Blanc, for me, and a case each of their 2007 Haut Garrigue reds which they are re-naming Resonance.

A little earlier, I visited my old friend Francis-Xavier at Chateau de Tiregand, accompanied by my new friend Klaus Einwanger, who has been taking the photos for the forthcoming Bruno cookbook. (You can find examples of his prize-winning work on www.foodfactory.de). 

In the cellars, we tasted the 2011, which is about to go into barrels and which promises to be a splendid wine. And he kindly gave me a rare bottle of the 2001 which I served at a small dinner for Raymond and the baron. 

We began with smoked trout from the Isle of Mull in Scotland, which we drank with a bottle of Monthuys champagne. With the Tiregand I prepared one of my favourite dishes, aiguilettes de canard au miel et aux grains de moutarde, to which I added a splash of Armagnac, and accompanied it with potatoes from the garden. 

The wine was magnificent, smooth and gentle at first and then its strength slowly became more apparent. We drank it in something close to reverence.

According to a study published by the journal Proceedings of the National Academy of Sciences in conjunction with Conservation International, global warming could have a perilous impact on the vineyards of the Dordogne.

With the world getting warmer, traditional wine-growing regions including (but not limited to) the Dordogne could see a significant fall in production over the next forty years, with Conservation International forecasting a two-thirds drop in output.

The hot dry summers so typical of Aquitaine are not just attractive to the legions of tourists who journey to southwest France each year – they are crucial to the region’s vineyards, who rely on the sun to do its job plumping the grapes that will become some of the best-known wines in the world.

The study examined the potential effects of two different temperature increases on nine of the world’s greatest wine-growing regions – a ‘moderate’ 2.5˚C rise, and a more dramatic ‘worst-case’ 4.7˚C increase. Seventeen climate models were used in the course of the study.

Bordeaux, Rhone, and Tuscany were hardest hit by the researchers’ models, and showed an 85 percent drop in production by 2050.

“The fact is that climate change will lead to a huge shakeup in the geographic distribution of wine production,” said study author Lee Hannah. “We expected to see significant shifts, but we didn't expect to see shifts like these.

“It will be harder and harder to grow those varieties that are currently growing in places in Europe,” Hannah added. “It doesn't necessarily mean that [grapes] can't be grown there, but it will require irrigation and special inputs to make it work, and that will make it more and more expensive.”