22. Warm-weather Crops: Grapes
S Subak and DH Lister

Total area of vineyards in production in the UK

Specific Indicator
In the long term, it might be expected that global warming will enable the small wine production industry in England to expand, and so this indicator is included to monitor the area of vineyards in production in England & Wales. However, in the short term, expansion may be more related to the niche market, economies of scale and tourism rather than climate.
[Source:Ministry of Agriculture, Fisheries and Food, 10 Whitehall Place, London SW1 2HH]

Relevance
English vineyards are currently of recreational value for visitors on wine-tasting tours and for about 100 small producers. There are also a few vineyards in the country that operate on a truly commercial scale supplying supermarkets with domestic wine, but these account for only about 0.3% of UK wine consumption. Therefore, this indicator's chief interest is as a cultural symbol of a crop that flourished in the warmer climate of Roman Britain and which represents a proxy indicator for the perception of climate changing towards southern European conditions.

The grapes produced in English vineyards are currently dominated by hardy, hybridized varieties developed in Germany. Hybrids are authorized for use by the Ministry of Agriculture, Fisheries and Food in the regional wine scheme (but not in the quality wine scheme). About 80% of British wine is produced in the southeast and Anglian regions of England.

Sensitivity to climatic and other factors
Vineyards aiming to produce good quality grapes as well as high yields are struggling in the present climate because, in most years, production has been limited by spring frosts, or by too few degree-days for complete ripening. In some years, such as 1993, wet weather reduced the crop. Most wine was produced in 1983, 1989 and 1992, which were relatively sunny and warm. Although the exceptionally warm years of 1995 and 1997 produced an excellent vintage, quantities were low because of spring frosts.

Aside from climate, extension of vineyard area will depend upon the personal interests of small producers, the establishment of a niche market and foreign competition. The current upward trend in production appears to be related to recreational interests and perceptions of a warming climate, rather than to recent weather.

Change over time
The area of vines in production has more than doubled over the period of record, from around 350 ha in the late 1980s to around 800 ha in the last five years. The area in production is known since the mid-1980s, although grapes were produced by a few pioneers in the decades after World War II. A notable increase occurred in 1989, reflecting vine-planting three years previously. Heavy summer rains greatly reduced the 1993 crop and obviously had a discouraging effect in that the productive area fell in 1994. The area under production reached a maximum in 1998 of 842 ha, and has remained relatively stable since then, declining gradually to 783 ha in the latest year of record, 2002. It will be of interest to see whether market forces have placed a cap on the area of productive vines in England and Wales, or whether the upward trend of the early years of the record can be re-established. The potential to produce greater quantities of grapes and a better quality of wine accompanies the prospect of a warmer climate, and so, in the long term, we might expect to see a further increase in production area in the future.