From the elevated, panoramic terrace of the winery's restaurant, rows of vines stretch straight and even to the foot of the steep chalk ridge facing me and for as far as I can see to either side along the valley. It is November, and the leaves are mottling yellow and brown and falling away to compost around the rootstocks. Behind me, the hundreds of tonnes of grapes produced by these vines over summer have finished their first fermentation in the winery's vast and clinically clean stainless steel tanks. These base wines will soon be tasted and blended by the winemakers before being aged on their lees in the bottle in the traditional 'méthode champenoise' to acquire their flavour and fizz. The quality of the fruit this long, warm summer produced suggests that this year's vintage might be one of the best-ever. We'll know in three years.

But I'm not in Champagne. On the other side of that long, high ridge lies the English Channel, and I'd need to cross it and travel another 200 miles south-east through France to reach the region most famous for its sparkling wines.

Instead I'm at the Rathfinny wine estate at the heart of English sparkling wine country, centred on the southern counties of Sussex, Kent and Hampshire. It is nearing winter in northern Europe yet it is unusually warm and I can wander through Rathfinny's vines comfortably in just a sweater. But perhaps we need to rethink what constitutes 'unusual' weather. Making great wine is a complicated and delicate balance of skill and soil but most importantly sunshine, and the one-degree increase in average global temperatures is having a dramatic effect on winemakers around the world. In just forty years, the ideal climatic conditions which produced the champagne that Julia Roberts drank (with strawberries) in that famous scene in Pretty Woman have shifted 200 miles north here, to southern England. There are other reasons why this is now one of the world's fastest-growing and most exciting wine regions, but the single most significant is climate change.