**1. Introduction**

Climate change is one of the most important issues in science today. It is also an extremely complex and multidisciplinary aspect [1,2]. Climate change is a general threat to food production. The two regions of the world with the highest growth due to malnutrition (PoU) are Asia (418 million) and Africa (282 million people affected by hunger) in 2020 [2,3]. Food insecurity is growing steadily around the world, especially in the African region. Severe global food insecurity is witnessing a huge increase from 8.3% (605 million) in 2014 to 11.9% (928 million) in 2020 [4]. Yields of wheat, maize and other crops are slowing in many countries due to extreme heat, severe weather conditions and droughts [1]. According to some estimates, in the absence of effective adaptation, global yields could fall by as much as 30% by 2050. Global warming, according to the FAO [2], will lead to rising costs of bread, market shocks and political unrest. In recent years, climate change in many countries of the world has been associated with food insecurity, especially in developing countries; for example, this is observed in many African countries such as Nigeria, Senegal, Guinea and others [4]. Serious food insecurity problems also exist in many developed countries in Europe and North America, particularly in some rural areas away from major urban centers.

**Citation:** Sawicka, B.; Barba´s, P.; Pszczółkowski, P.; Skiba, D.; Yeganehpoor, F.; Krochmal-Marczak, B. Climate Changes in Southeastern Poland and Food Security. *Climate* **2022**, *10*, 57. https://doi.org/ 10.3390/cli10040057

Academic Editors: Christopher Robin Bryant, Andrea Vitali and Azzeddine Madani

Received: 31 January 2022 Accepted: 4 April 2022 Published: 6 April 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

In these areas, human populations may be unsecured from the food side, as this population is usually poor [3,4]. Reducing precipitation will strengthen the desertification process, mainly in the outskirts of the Sahara and Southern Africa. In the case of Asia, climate change will affect the diversification of the production potential of agriculture in individual countries. The most unfavorable changes will occur in poor countries, especially in the coastal areas of the monsoon zone. Rising sea levels will flood some farmlands and worsen the availability of fresh water [3,4]. Kulig et al. [5] and Ziernicka-Wojtaszek [6,7] point out that if the warming trend continues, significant changes in the structure of crops may also occur in Europe, especially in Southeastern Europe, including Poland. For example, on the one hand, it will be possible to introduce plants with increased thermal requirements (maize, sugar sorghum, sweet potato and grapevine) on a larger scale, and on the other hand, the acreage and yields of certain agricultural cultures will be significantly reduced. These climate changes can have a serious impact on food production and have the potential to limit the production of staple food raw materials, such as potatoes [5,8,9]. The temperate climate zone in which Europe is located shows the greatest variation in climatic conditions among all zones. It distinguishes a group of cool climates and a group of warm climates, including maritime, transitional and continental climates. Due to the favorable conditions for agriculture, this zone is the food basin of the world. Strong warming has been observed in the last three decades. Central Europe, including Poland, is also experiencing this. The forecasts for Poland also predict further warming, as well as changes in the spatial and seasonal distributions as well as the amount of precipitation. However, climate models do not agree on the direction of these changes. Rainfall in Poland is expected to decrease in summer (it depends on the model) and increase in winter. Consequently, there is still considerable uncertainty about the likely impact of climate change on Poland's water resources. In general, changes in thermal characteristics, precipitation and air humidity will have an impact on changes in water balance and, thus, on the productivity of crops and the country's food security. Due to the insufficient consistency between climate models, the scope of changes may differ depending on the model and biotic and abiotic factors. Climate change trends in Poland, in terms of temperature, precipitation and relative humidity, in the southeastern part of Poland based on global the scenarios for climate and emissions (according to IPCC AR5) are presented in the studies by Kulig et al. [5], Ziernicka-Wojtaszek [6,7] and Mezghani et al. [10]. In general, all climate models show a systematic upward trend average air temperature, both in the short term and as well as the future. Significant regional differences between simulations and seasons were found. However, some simulations were not very good at recreating the temperature gradient from the northwest to the southeast of Poland. This applies, inter alia, to the topographic influence of the mountains in the south of the country, which can be seen, for example, in orographic and convective rainfall [10]. Data from a common subset of global climate models show greater changes in precipitation and less warming than the average based on the full set of GCM models. This means that the predictions based on a subset of global climate models used in Poland cover a limited range of possible climate change, compared to the entire set of GCMs. This is especially true of air temperature, while in the case of precipitation there is almost the same range of variation. Total rainfall is likely to increase by 2035, then changes will stabilize and will be approximately + 6% by the end of the 21st century. In the study of climate change, apart from the course of precipitation and air temperatures, it is also analyzed [7,10]. The average daily value of the Humidex Thermal Discomfort Index, which combines the influence of temperature and air humidity. High values of this index may affect the feeling of thermal discomfort even in healthy people, worsening the health of people suffering from heart and circulatory system diseases, and may accelerate the outbreak of fungal diseases, including potato blight epidemics, and affect the rate of its spread [5,10,11]. However, there is a well-founded fear that with the increase in sensitive meteorological data and the effects of these changes, the risk of unfavorable climate changes in the region of Central and Eastern Europe may begin to

increase again, which may be particularly conducive to the spread of dangerous potato diseases [5,11–13].

The impact of climate change on Polish agriculture was studied by focusing on the potato, assessing the unfavorable growing conditions in the time horizon of 2000–2019. Among the many pests that attack potato crops in almost all regions of the world, potato blight (*Phytophthora infestans* Mont de Barry) dominates, a fungus-like organism that is responsible for the most dangerous disease in potato plantations and was responsible for the famine in Ireland in 1843–45 and continues to cause worldwide devastation with respect to potatoes. Moreover, this disease reappears in the form of different genotypes and causes huge losses in potato yields [11–13]. Its harmfulness consists in destroying the aerial parts of plants, which in turn results in a reduction in the assimilation area and, thus, the quantity and quality of the yield of progeny tubers. The development of the disease is closely related to the meteorological conditions in potato plantations. The disease develops most rapidly in conditions of high humidity (prolonged rainfall or long-lasting fog) and air temperatures between 12 and 18 ◦C. In such favorable conditions, if chemical protection is not applied, up to 10% of the assimilation area of potato plants can be destroyed daily—while the destruction of more than 50% of leaves and stems stops the accumulation of tuber yield under the bush. Crop losses on unprotected plantations in Europe reach 70–80%. In some years, the disease appears on plantations very early, even in May. If the meteorological conditions accompanying primary infections are favorable for the development of this disease, then we are dealing with very early epidemics of potato blight and the premature destruction of tops across the field, which significantly affects the size and quality of the crop. In the case of very early infections, potato yield losses may reach even 100%, which directly threatens the country's food security [13–16]. The occurrences and intensities of *P. infestans* on the aerial parts of plants and then on tubers are strictly dependent on the meteorological conditions and the source of the pathogen in the field. The periods of increased air humidity, caused by long rains or long morning mists or dews (RH > 90%) and low temperatures (approx. 15 ◦C), favor the development of the pathogen causing potato blight. If this type of humid weather persists for several days in June or early July, massive plant contamination can be expected. Under such conditions, *P. infestans* spores turn into zoosporangia, containing 6–16 tidal spores, which are easily released into the environment, causing massive plant infections and resulting in a high reduction in tuber yield [16]. Lower humidity and air temperatures above 18 ◦C contribute to *P. infestans* spores directly by germinating and infecting neighboring plants.

The further development of this pathogen is not only the most intense at temperatures above 20 ◦C but also at increased ambient humidity. Under such conditions, potato cultivation may be destroyed by *P. infestans* within a week, and in extreme cases, even within 2–3 days. The pathogen's spores can spread with wind or rain for a distance of even several dozen kilometers, which facilitates the immediate spread and spread of this disease [17,18]. The harmfulness of potato blight is related both to the decrease in the yield obtained and to the direct infection of tubers. The reduction in the yield is the result of the disease destroying the above-ground part (assimilating surface), leading to the inhibition of tuber growth, which directly threatens the food security of the country's inhabitants [10,15,16].

It is possible to estimate the risk of a decrease in potato yields as a result of potato blight (*Phytopthora infestans* Mont de Bary), which is the reason for a significant drop in the yield on the basis of historical data [8]. The rarity of unfavorable meteorological phenomena and the short period of their recording, however, may not capture the real risk [5]. One way to solve this problem is to simulate the values of air temperature and humidity, rainfall and wind speed to obtain a broader picture of the risk of this disease, which can significantly reduce potato yields.

The 1996 World Food Summit established that food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that

meets the nutritional needs and preferences of an active person and a healthy lifestyle [1,2]. This widely accepted FAO definition identifies the following pillars of food security:


Food uncertainty is likely to deteriorate drastically in many situations and in many countries, especially in Central and Eastern Europe, in the near future [1,3,4]. According to FAO [1], the main factors driving the food crisis include armed conflicts usually followed by extreme weather conditions and climate variability.

Potato production is related to food safety and food security. Several different aspects of food security have been developed in recent years. Food security can not only be considered in various aspects—international and national—but also from the point of view of the household. In the international dimension of food security, the need to combat hunger is indicated [3,4], where food is perceived in terms of a public good. On the other hand, in the national dimension, the emphasis is on the appropriate institutional policy. The aim is for each country to improve its own food law, making the idea of food security a reality.

Hence, the aim of the study was to find the relationship between climate change in Southeastern Poland and the threat to the safety of the potato crop as the basic food raw material [11,12,18]. On this basis, an alternative research hypothesis has been formulated, which assumes that the earlier forecasts of the potential impact of adverse climate changes conducive to the outbreak of *P. infestans* and the development of this pathogen may allow emergency managers who plan ahead for the occurrence of high risk to prioritize conservation measures plants and save the yield, in view of the null hypothesis that these activities do not affect the outbreak of the epidemic and cannot prevent a decrease in potato yields due to the development of *P. infestans.*
