Climate change impact on viticulture in Poland

3.1 Winegrowing under climate change

Understanding of the impacts of climate change on natural systems has become increasingly relevant as changing levels of greenhouse gases and shifts in the earth’s surface modify the hydrological cycle, earth’s radiation budget and atmospheric circulation (Houghton et al., 2001; Vink et al., 2012; Abbott and Wilson, 2014). These observed trends and future changes will impact agricultural production through changes in the length of growing seasons. Changeability in winter hardening could have a considerable affect upon productivity and viability of diverse agricultural production (Moonen et al., 2002). A good understanding of weather and climate change impacts is particularly important with viticulture and grapevine cultivation. Historical records and present observations have already shown a significant impact of climate variability on grape production. To date, research has mainly concentrated on perception of weather extremes and adaptive changes in the context of severe events such as drought, heat waves and floods (Keller, 2010; Shanmuganathan et al., 2012; Tate, 2001). However, these evaluations of impacts on viticulture principally rely on worldwide climate models (White et al., 2006). In contrast, there is empirical evidence that temperature-based indices have a crucial impact on grape production (Schultz, 2000; Stock et al., 2005; Nesbitt et al., 2016). There is a strong correlation between good vintage and annual weather conditions. According to Becker (2003), climate change can improve the quality of various varieties due to favourable thermal conditions that can be expected in numerous growing regions. On the other hand, varieties that are adapted to cooler conditions can suffer imbalances in flavor components with rising temperature. According to Webb et al. (2007), grapevine phenology is highly sensitive to the various greenhouse gas emission scenarios. Moreover, climate change affects phenology, as well as pathogens and insects life cycles, which may bring new risks for the timing of phytosanitary treatments (Battaglini et al., 2009). A change in climatic zones will create potential for spread of thermophile pests and diseases. Furthermore, climate change will lead to shifts in the suitability of wine-growing regions for the production of unique types of wine and could upset the competitive balance between diverse regions (Kenny and Harrison, 1992; Tóth and Végvári, 2015). According to Hannah et al. (2013), as a result of climate warming in the next decades (up to 2050), the most important European wine regions such as Tuscany and Bordeaux will lose between 19 and 73 per cent of production capacity. Rising temperatures will make grape growing viable in places that are currently considered to be uneconomical, including mountain slopes and river valleys in central China, Canada, central Europe and most of Poland.

The mid-term scenarios of climate change in Poland during the twenty-first century in the framework of the Klimada project were prepared using climate models (Sadowski, 2012). The results of scenario analysis show an increasing temperature across the country, varying regionally and seasonally, but strongest in the past three decades of the twenty-first century. Using climate scenarios for the years 2021-2050 and 2071-2100, it has been calculated that a grape growing season in Poland (determined by number of days with daily air temperature higher than 5°C) will be 16 days longer between 2021 and 2050, compared to the years 1971-2000, and 41 days longer for years 2071-2100. This will significantly accelerate the growth of plants. The analysis of the impact of agro-meteorological conditions on the yield of crops in Poland has shown a trend toward loss of yield as a result of drought risk. An increase in the frequency of yield losses is expected, with relatively small changes in average yields. Thus, the observed changes in thermal conditions and the impact of these changes on the phenology of crops will initially require changes in field work periods. In the longer term, adaptation of cultivation structures will be required.

In summary, changes in climate will create a strong element of uncertainty in grape production. The wine industry is very often recognised as vulnerable to climate change, due to its specific dependence on particular terroirs that are significantly climate related. Accordingly, the wine grape industry is perceived as an early warning indicator for agricultural industries in different countries.

3.2 Winegrowing in Poland under climate change

In the European Union’s classification of climate for viticulture (Council Regulation No 479/2008), Poland was classified in the coldest winegrowing region and officially acknowledged as a wine-producing country, together with Germany (except for Baden), the Czech Republic (except for Moravia), Belgium and Great Britain. Polish territory was divided into three regions based on temperature: Region I (the west and southwest of the country, namely, provinces of Lubusz, Lower Silesia, Opole and Silesian and southern parts of the provinces of Wielkopolska and Lodz); Region II (threatened with more frequent cold winters, covers the south and southeast of the country, i.e. the provinces of Małopolska, Podkarpackie, Świętokrzyskie and southern parts of the provinces of Lublin and Warsaw); and Region III (the other areas, where viticulture is impossible or very difficult) (Figure 1). According to Lisek (2008), the current climate changes are conducive to the development of Polish winemaking. The average annual temperature has shown an upward trend (about 0.5°C per decade), transitional periods have been shortened, warm periods have been prolonged and winters have become milder, allowing the cultivation of early and very early varieties or varieties sensitive to chilled temperatures. Lisek (2008) stressed that out of all the climatic changes noticed in the past several dozen years, the most favourable for grapevine growing is increased annual air temperature during the growing season, expressed as the so-called sum of active temperatures. This consists of the daily temperature averages above 10°C. His research showed that, on average, the beginning of the phenological stages of bud swelling, blooming and fruit ripening of grapevine cultivars in the years 2005-2007 occurred 12 days earlier than in the period 1987-1989. In recent years, however, climate fluctuations, especially increase of temperature during the growing season, have led to new issues concerning plant protection against pests and diseases. Some of the most important problems are more and more frequent grapevine infections with fungus. Additional threats include solar injuries to grapevine leaves and fruits caused by thermal (infrared) and ultraviolet (UV-B) radiation.

3.3 Wine production in Poland

Wine production in Poland is linked to the obligation to report to the Agricultural Market Agency (AMA) on production volumes and stocks of wine. Under the Common Agricultural Policy, AMA implements measures to determine the production potential of vines and wine in Poland. The purpose of these activities is to assess the volume of grape harvest and the production of wines and vine crops and to monitor the market. However, some vineyards do not produce wine for market purposes and are not obliged to register with AMA. At present, there are about 500 vineyards, with estimated area of 700 ha (Figure 2). Out of this number, 155 farms registered with AMA in 2016, representing a total area of 238.2 ha. There is clear dynamic growth in the number of registered farms and the registered area of vineyards for wine production in Poland. From 2009/2010 to 2016/2017, the industry has grown more than 20-fold, but starting from a low base of only 26 farms. During the same period, the production of wine increased 17-fold, from 41,249 to 699,382 dm³, with average 50 per cent annual growth in the analysed period. The size of already existing vineyards, which are included in the records, ranges from less than 1 ha (about 75 per cent) to over 12 ha (AMA, 2017).

Most of the vineyards could be found in the belt of south-eastern, south-western and southern provinces, which have the most favourable climatic conditions. Listed regions are characterised by higher temperatures, optimal conditions of sunlight and longer growing seasons than the rest of the country. Moreover, natural conditions offered by these regions are optimal for cultivation of popular cold-hardy and disease-resistant hybrid grape varieties, e.g. Seyval Blanc, Solaris, Hibernal used for white wine production or Rondo and Regent used for red wine production. Vitis Vinifera species, such as Riesling, Pinot Noir, Chardonnay, Merlot and Zweigelt, are also frequently grown in these regions.

In this context, it needs to be noted that the Polish wine market has seen dynamic development over past decades. Zmarzłowski and Ochnio (2013) reported that it has developed due to the increasing share of wines in the domestic alcohol consumption. Tul-Krzyszczuk, and Kołakowska-Paszkiewicz (2008) argued that this market has a growing potential which will be stimulated by the buyer's bargaining power and growing wine culture. Polish consumers are discovering classic grape wine, looking for high-quality and healthful products, paying also the attention to their price. Smith and Mitry (2007) informed that in spite of increasing popularity of wines, the Polish wine market is rather small in contrast to the European market. A comparison with other European countries distinctly shows that it is in a state of rapid change and has some years of growth ahead before reaching maturity (Schaefer et al., 2018).

3.4 Results of the model

The results of the LPM estimations show that there are important current and future climate change factors that could influence the cost-effectiveness of viticulture in Poland. The probable impact has a dichotomous character. It is expected that climate change will positively influence farm operations, but indirect effects will have a negative influence too (Table I).

It was estimated that under ceteris paribus conditions, the likelihood of maintaining cost-effective viticulture in Poland increases by 21 per cent due to regional location of the vineyard. It was thus confirmed that climate and weather conditions have a systemic character and are interdependent with terroir. Changing weather and climate conditions in case of Poland will impact the opportunity conditions to start the cultivation of vineyards. Such cultivation will become an alternative strategy for farmers, whom anyway will be faced with the need to adjust activities according to changeable climate conditions. These conditions will influence the economic tension to grow suitable plants, which will provide an economic benefit. Winegrape growing could be such strategy for Poland. A similar situation, with a higher significance level, could be observed in the case of cultivated variety. The model’s results show almost 50 per cent probability that cultivated variety, under climate change, will have a positive impact on farm operation and effectiveness. This indicates that in the near future, the list of varieties might need to be revised to select those most suitable for the new conditions. This, however, will require new investment which could reduce the likelihood of implementation. Only the farmers that will be able to effort the costs of buying cuttings of new varieties, adding new field quarters and waiting for return on such investment, which will be connected also with the promotion on new wine, will build their competitive position on the market. Also, the careful calculations will be needed to investigate both trade-off effects between profiting from already growing varieties and costs of growing new one and spillover effects of growing new varieties, i.e. for enoturism.

The model estimates also suggest that the overall forecasted changes of weather conditions during the vegetation period will have an impact on the cost-effectiveness of farms. There is almost 50 per cent probability that if the forecast changes take place, much better conditions will be created for viticulture production in Poland.

Nonetheless, there are forecasted also negative effects for farm economics due to climate change. These are indirect effects related to biotic and abiotic stresses that arise from climate change. Abiotic stresses analysed in the model showed cooling and overheating jointly with radiation stresses. The results showed that in case of cooling stress, the farms’ cost-effectiveness will decrease by half and in the case of overheating by one-third. Similarly, biotic stresses such as diseases could reduce farm effectiveness by 27 per cent. In the longer term, biotic stresses such diseases and pest occurrence might have negative impact on viticulture. Should climate change conditions cause an increase in the occurrence of pests such as mites or aphids, there is 23 per cent probability that the viticulture production will be less effective. Similarly, the increase of diseases such as powdery mildew, might lower farm effectiveness by 35 per cent.

Mozell and Thach (2014) showed that global warming has direct, and sometimes quite severe, implications for both vineyard management and wineries. Climate changes and their effects are remarkable, but winegrowers are not fully aware of them (Battaglini et al., 2009). However, they could undertake adaptive measures to minimise the associated risk. Bernetti et al. (2012) have shown that adaptation actions undertaken to adjust to climate change, which can be considered as innovations at the farm, lead to a 61 per cent probability of maintaining current levels of income. The most important result of their research, however, is that farms tend to respond to climate change without stopping production. They are adopting innovations as a response to climate change. Climate change factors will impact economic performance of viticulture and could consequently also encourage innovation in the sector.