3.5/3.6 Weather & Climate Change

Question 1

What is weather?

Answer 1

• A region’s weather is the annual variation that happens relative to the climatic average.
• Some regions experience greater variation in this pattern than others

Question 2

Give an example of a region that has a large variation in annual weather. Describe why.

Answer 2

• The amount and timing of rainfall in Bordeaux can vary quite considerably
• In 2007 the region was cool, cloudy and wet during most of August
• In 2003 high temperatures and near drought conditions were experienced

Question 3

Give an example of a region that has predictable weather patterns.

Answer 3

• Central Valley in California

- Hot, dry weather from one growing season to the next.

Question 4

What is vintage variation? What can this lead to in the winery?

Answer 4

• When weather has a significant influence on the wines produced in that year
• Influence sugar and acid levels, and tannin and aroma/flavour ripeness.
• Leads to adjustments made in the winery

Question 5

How can weather affect yields?

Answer 5

• Rainy years can bring more fungal disease, reducing yields

- Spring frosts can also lead to significant reductions in yield, especially if no frost protection is available

Question 6

Why can high yields be problematic in the winery?

Answer 6

• The winery may not have the capacity for the increased volume of fruit
• Finding routes to market/customers for all the wine (at a profit) may be difficult.

Question 7

Give an example of how weather might affect the styles of wines produced in a certain year.

Answer 7

In some regions, winemakers may adapt by producing different styles of wine in cooler years (e.g. more sparkling wine or rosé) compared to warmer or drier years.

Question 8

What is the main measurable effect of climate change? What are other effects?

Answer 8

• Main: rise in temperatures
• Greater evapotranspiration (leads to water stress)
• Changes in the geographical distribution of rainfall
• Greater weather variability
• Greater frequency of extreme weather events

Question 9

How has rising temperatures affected the vine cycle?

Answer 9

• In warmer temperatures, the vine cycle is faster
• Budburst occurs earlier in the spring; each stage of the vine cycle becomes quicker
• Speeds up the rate of sugar accumulation and reduction of acidity
• Does not quicken the ripening of most aroma and tannin compounds

Question 10

What must be done to accommodate the effect of climate change in warmer climates?

Answer 10

• In order not to compromise the ripeness of aromas and tannins and the accumulation of colour, grapes may be picked with higher levels of sugar, causing higher alcohol levels in wines and lower levels of acidity.
• The more rapid fall in acidity can give wines with higher pH levels, and this could be problematic in winemaking.

Question 11

As the climate warms, are early-ripening or late-ripening grape varieties in danger? Why?

Answer 11

• Early-ripening
• Late-ripening typically require more time
• With sped up, ripening, late-ripening will ripen quicker but will result in more balanced wines

Question 12

What regions might benefit from climate change?

Answer 12

• Regions and countries that have previously been too cold to ripen grapes
• Regions that experience plentiful rainfall in the growing season (drier conditions will help reduce fungal diseases)

Question 13

What regions are experiencing excessive temperatures and/or drought? What does it mean for the future of these vineyards?

Answer 13

• Parts of California and South Africa

- Regions may have to be abandoned in the next 50–100 years

Question 14

In what 4 ways have many grape growers and wine businesses started to act to mitigate and to better adapt to the effects of climate change?

Answer 14

1. Practise sustainable techniques such as using renewable energy resources and protecting natural ecosystems
2. Site selection
3. Choice of planting material
4. Efficacy of different vineyard management techniques