The impact of climate change on viticulture in Poland and Portugal

I. CONTENT

1. Introduction

2. Review of the Literature
2.1 Definition and Causes of Climate Change
2.2 Climate Change Impact on Viticulture
2.3 Poland
2.3.1 Wine Industry
2.3.2 Viticulture
2.4 Portugal
2.4.1 Wine Industry
2.4.2 Viticulture

3. Discussion

4. Publication bibliography

II.FIGURES

Abbildung in dieser Leseprobe nicht enthalten

III. ABBREVIATIONS

Abbildung in dieser Leseprobe nicht enthalten

1. Introduction

Climate change is omnipresent. Its impacts on ecological, economic and social dimensions are significant. Also, in viticulture climate change has a major impact and affects the winemaker’s practice both in the short-term and in the long-term. Nowadays, the wine-growing area in Europe is mainly situated at a latitude between 30° and 50°N (northern hemisphere). Climate change, specifically global warming, affects those boundaries and challenges the current viticulture as well as traditional pathways. The impact of climate change will not take course in a homogenous way. The wine-growing regions are affected differently, partly with more positive or more negative outcome. To visualize those different effects on the wine-growing regions - and the range of possible impacts - this work will have a closer look at the cool-climate country Poland and the warm-climate country Portugal. The working assumption is, that the winemaking sector in cool-climate countries benefits from global warming effects, whereas warm-climate countries have to face major negative impacts and do have a higher urgency for adaption measures.

2. Review of the Literature

To explore the impact of climate change on the countries Poland and Portugal, this literature review covers: 1. Definition and causes of climate change, 2. Impact of climate change on viticulture in Poland, 3. Impact of the climate change on viticulture in Portugal.

2.1 Definition and Causes of Climate Change

A major aspect of the climate change is the global warming. Global warming is the longterm rise in the average temperature of the Earth's climate system referring to both atmospheric and oceanic temperatures (Mozell and Thach 2014). The primary cause of global warming is the greenhouse effect. The primary greenhouse gases found naturally in the atmosphere are water vapor, carbon dioxide, methane, and ozone. Besides others, burning of fossil fuels, deforestation, and the loss of natural carbon sinks are contributing to global warming (Mozell and Thach 2014). Human activities significantly raised the atmospheric carbon dioxide levels in the last 150 years: "Human influence on the climate system is clear, and recent anthropogenic emissions of green-house gases are the highest in history” (IPCC 2014). Globally, economic and population growth continue to be the most important drivers of increases in CO2 emissions from fossil fuel combustion.

Besides rising mean temperature levels, projected and ongoing changes include also declining sea ice extent, rising sea level, acidification of the oceans and occurring extreme weather events. Figure 1 shows the projected changes in the global mean surface temperature and global mean sea level rise under different RCP scenarios for two periods of time. Under all scenarios, a rise in temperature and sea level will occur.

Abbildung in dieser Leseprobe nicht enthalten

Figure 1: Projected change in global mean surface temperature and global mean sea level rise for the mid- and late 21st century, relative to the 1986-2005 period (IPCC 2014, p.60).

Climate change is a threat to sustainable development. Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system. Limiting climate change and its risks need substantial and sustained reductions in greenhouse gas emissions (IPCC 2014).

2.2 Climate Change Impact on Viticulture

The presence of climate change and its impact on viticulture are real. Global warming causes problems for the traditional wine-producing regions and shifts the viticulture zone northwards, e.g. the Netherlands and Denmark in Europe. Some of Europe's most important wine regions - such as Tuscany and Bordeaux - will deal with major challenges, whereas rising temperatures will make grape growing viable in places that are currently considered to be uneconomical or not suitable for wine-growing. For cool-climate areas this might go along with an improvement of the grape quality because of more favorable thermal conditions. For warm-climate areas, rising temperatures become critical for existing varieties and viticulture but might be beneficial for the sweet wine production. In any case, increased dryness will have a strong negative impact on wine production and quality in some parts of southern Europe, particularly in latitudes southward of 40°N, including Portugal (Malheiro et al. 2010). Overall trends show significant changes in each wine region: "During the last 30-70 years many of the worlds wine regions have experienced a decline in frost frequency, shifts in timing of frosts, and warmer growing seasons with greater heat accumulation” (Jones 2007, p.3). Those climate changes cause a shift in the grape chemistry but also changes the normal pattern of grape development towards an earlier onset of flowering, veraison, and harvest: "Shifts in grapevine phenology, disease and pest patterns, yield and ripening potential, and wine styles are projected to take place in response to future conditions” (Malheiro et al. 2010, p. 164).

Indices

There are several climate-based indices to describe the suitability of wine growing areas. Two of the most common indices are the Huglin Index (HI) and the Winkler Index (WI). The HI estimates the temperature suitability of certain regions for various grapevine varieties. It ranges from values lower than 1500 °C in the very cool regions up to values higher than 3000 °C in the very warm regions (Santillan et al. 2019). It is based on the assumption that each variety depends on a certain heat accumulation to be able to grow successfully in a particular area over a longer period of time (Hoppmann 2010). Due to the climate change, the HI will continue to rise over coming decades and the suitability of an area for a specific grape variety will change. Referring to Poland this means, that regions with HI<1500°C (no growing recommendation) might shift to more suitable winegrowing regions with at least HI =1500°C and higher. Portugal, on the other hand, might shift to a very high HI with up to 3000°C or more, and might partly develop into a region too hot to cultivate many varieties.

The Winkler Index (WI) classifies the climate of wine growing regions based on heat summation or growing degree-days. Geographical areas are divided into five climate regions I-V. Considering the WI, Poland belongs to Winkler region I a and Portugal to region IV. Still, it needs to be considered that within one country the climatic conditions are not homogenous and vary between regions and elevations.

Malheiro et al. combine those two indices plus five more to analyze the impact of the projected future climatic changes in the European viticulture geography. During the 21st century and under the A1B scenario a significant northward extension of the suitable wine-growing regions to 55°N is projected (Malheiro et al. 2010). In large areas of central and western Europe climatic factors are projected to become more suitable for grapevine growing (e.g. Poland), while in most of low-altitude regions in southern Europe grapevine growth is expected to face excessive dryness (e.g. Portugal) (Malheiro et al. 2010).

Abbildung in dieser Leseprobe nicht enthalten

Figure 2: Composite Index. Projected future climatic changes in the European viticulture geography (Malheiro et al. 2010, p.173)

Adaption

Adaption activities will be very important to tackle the challenges of climate change in viticulture. Besides a variety of short-term measures (e.g. adjust harvest picking time, allow irrigation system), there are also possible long-term measures (e.g. move towards higher elevations, selection of varieties with higher thermal requirements, selection of more drought tolerant rootstocks). Temperature differences across regions indicate that adaptation may be significantly more difficult in some regions than others. For example, further warming in Poland will move this region closer to the temperature optimum, whereas in Portugal, further warming will leave few, if any, options for viticulture in the very warm regions (Ashenfelter and Storchmann 2016). Also, adaptability in many European countries is limited, more in Portugal than in Poland: Portuguese wines are more closely tied to their geographical origin, and terroir. Also, the regime of planting rights in Europe might impose limitations.

2.3 Poland

2.3.1 Wine Industry

Poland does not belong to the famous or well-known wine countries, yet. It is "not perceived as a country with suitable climatic conditions for wine production” (Maciejczak and Mikiciuk 2019, p. 254). Anyway, there is an increasing share of wines in the domestic market and a growing wine culture. In 2020, the turnover in the segment wine is projected with 1.407m €. According to prognosis, the market volume will be 1.795m € in 2023 which corresponds to an annual growth rate of 8,5% (CAGR 2020-2023). In 2020, the average per capita consumption is projected with ca. 4,8l respectively 37,17€ (Statista 2020a). The Polish wine industry, still at a low level, is very vibrant and positively developing.

2.3.2 Viticulture

Climate

Poland belongs to the cool-climate countries and is, not predestinated for viticulture. Along with other European countries like the Netherlands or Denmark, Poland belongs to the wine growing zone A of Europe (Blau and Nickenig 2018). Currently, the main climatic threats for wine growing are spring frosts, winter temperatures lower than -30°C, and - generally spoken - temperatures unsuitable for grape growing. Poland is characterized by significant seasonal and daily fluctuations in temperature with potentially frost and hailstorms during winter and spring. Viticulture in cool-climate areas is seen as more difficult and cost intense due to higher rainfall, spring or fall frosts, shorter growing season and lower yields on average (Anderson 2017).

Wine Regions

Poland extends from 49°N (south) to 54°N (north) which is equivalent to wine regions like Champagne or Rhine (Kunicka-Styczynska et al. 2016). The country is divided into three major wine regions based on the temperatures: region I (south and southwest), region II (south and southeast) and region III - with region III being currently the area where viticulture is most difficult or not viable. Most of the vineyards are situated in the south, especially southern eastern part of the country. This part of Poland offers more favorable climatic conditions for grapevine growing like higher temperatures, more sunlight and longer growing seasons than in the rest of the country (Maciejczak and Mikiciuk 2019).

Abbildung in dieser Leseprobe nicht enthalten

Figure 3: Polish Wine Regions (Maciejczak and Mikiciuk 2019, p. 258)

Grape varieties

Especially the climate in the southern part of Poland makes it possible to grow varieties of the Vitis vinifera, for example Riesling or Pinot Gris. A major part of the varieties grown in Poland consists of hybrid grapes which are more adjustable to cool-climate. The "average growing season temperature for Vitis vinifera should be between 13°C and 15°C: below 13°C means only nonvinifera (hybrid) varieties will prosper” (Anderson 2017, p. 23). Other authors are referring to a SAT above 10°C for Vitis vinifera (Maciejczak and Mikiciuk 2019). Generally, grapevines planted in a cool-climate zone must be cold hardy to withstand typical temperatures of -18°C in winter but also fluctuating temperatures in summer. Besides the high impact of the temperature, coolclimate grape quality is also influenced by solar radiation, rainfall, frost intensity and duration, temperature variability, and humidity levels during the growing season (Schultze and Sabbatini 2019).

Abbildung in dieser Leseprobe nicht enthalten

Figure 4: Top 20 Polish Red and White Wine Varieties (Przybek 2020)

[...]