CASA Group 5

Local Viticulture Climate Zones

Summers are getting warmer, winters are sometimes harsher, leading to more extreme conditions.

The annual average temperature of the United Kingdom is increasing. Based on data from the Met Office, we can see that over that last 30 years, almost every year brought a higher-than-average warmth. While the change of climate is a threat to most of us, grapevine prefers this weather and can adapt to the new UK ranges. Annually, rainfall has not changed significantly over the same period of time, but conditions, like the number of days with rain, can have an impact on harvests.

Europe: The Traditional Area of Viticulture

In the year 2000, the distribution of vineyard regions throughout Europe was concentrated within countries within the South. These vineyards form a part of the Old-World Wine. As shown, there were no vineyard regions within the UK. However, in just over 20 years, this trend has rapidly changed.

Temporal Trends of UK Viticulture

Each plot examines a changing element of UK viticulture over the previous thirty years. From how taste has changed in both production and consumption, to the rising presence of wineries, and a rise in exports of wine, a burgeoning market has become established within the UK. Yet, how do these temporal changes manifest themselves today?

The Regions of UK Viticulture

County Trends

Once we aggregate the location of vineyards to their county, the spatial distribution of viticulture becomes clear. The South-East of England hosts the majority of vineyards, measured by hectares. Specifically, Kent has 101 Vineyards, spanning 1,030 hectares. This equates to about 30% of viticulture across the UK. Closely following, the counties of Sussex and Hampshire contain a combined 190 vineyards throughout 1,230 hectares. It is undeniable that the South-East of Englands is the center of viticulture within the UK. To uncover why this is, continue scrolling.

The Climate of the South East

Each of these graphs compare annual precipitation, sunshine and temperature between the South East, and the entire UK.

To create a successful vineyard, grapes need a warm, yet relatively dry, environment, basked in sunshine. When comparing the differences between annual average measurements in the three climate factors, a clear distinction is present, and increasing. The South-East region has a warmer environment, with more sunshine too. These differences have exacerbated throughout the 185 years, exemplifying how climate change is altering weather patterns within some localities. Thus, the ideal environment for grape production is now undoubtedly situated within the South East of England.

However, precipitation levels within the South East are consistently lower then that of the United Kingdom . This may present as a limiting factor in the success of viticulture. Yet, in actuality, grapes thrive in dryer climates, such as those found within the traditional regions of viticulture in Southern Europe. This is because too much water can cause the vines to swell, and even burst.

Other environmental factors that can delaminate a successful vineyard, and the taste of the grapes, lie beneath the surface.

Rathfinny Wine Estate, Sussex

Beneath the Vine

Vineyards grow over 30 varieties of grape across the UK. Each variety requires specific levels of soil moisture, pH and bedrock geology, which can greatly alter harvest and taste of wine.

The ideal range for pH sits between 5.5 and 6.8, creating equilibrium for nutrients. If the soil is too acidic or alkaline, yields will decrease and create unhealthy vines with bitter or dull flavours.

Soil moisture should always be below 50%, allowing soil to be fertile and drain well. If the soil is too saturated, roots can beging to rot leading to unhealthy vines.

Finally, the bedrock beneath provides minerals and physical support for vineyards.

But how do these requirements translate to a single vineyard? The Rathfinny Wine Estate was established in 2010, and specialises in producing Pinot Noir, Chardonnay and Pinot Meunie, spanning 350 acres. Use the button on the map to explore the vineyard. Through extracting satellite data, all soil moisture levels fell below 50%. Moreover, most of the soil PH lies within the 6.6-6.7 range. This is ideal for the grapes grown in the estate. To explore more, click here.

When exploring the geology of Rathfinny, its south-facing slopes lie on the same chalk as the Paris Basin. Chalk provides a soft, yet cooling and porous alkaline bedrock, ideal for grapes for high acidity.

All of these measures highlight how the climatic factors within the South-East are ideal for successful viticulture. However, this isn't the same for vineyards beyond the UK.

Napa valley

Viticulture Beyond the UK

Whilst climate change has produced a new opportunity for viticulture in the UK, it would be negligible to exclude how other viticulture's have been adversely impacted.

Within Napa Valley, a region in California, wildfires commonly occur. The specific event shown, upon the 10th of October 2017, displays both the smoke from the event, but, more importantly, the damage. With the Near-Infrared Image on the right, areas that appear black have burned, and plants have been scorched. This is not an isolated incident, nor is it temporally restricted; within the previous decade, 50% of the land in Napa Valley have burned. Such events are increasing in frequency, alongside other natural events.

Globally, climate change is altering patterns of production and consumption. Whilst the expanding viticulture within the UK may be considered a benefit, the environmental cost of such a delicacy is high.