Keywords

1 Introduction

The impact of climate change on safe food production can be defined in two separate routes. In the first route, the direct impact can be observed through quantity and variability of yields and the indirect impact can be estimated via more occurring pests and diseases on plants. In the second route, the impact of climate change can be defined through changes in atmospheric CO2 concentrations, which is altering the nutritional quality (Picture 1).

Picture 1
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The impact of climate change on crop production

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All of these impacts have the potential to change the quantity, quality, and safety of food for every individual worldwide (Mbow et al. 2019).

Recent studies are confirming that there is a strong connection between climate change, in terms of higher air temperature, and crop yields (Hatfield and Prueger 2015; Liu et al. 2019; Parkes et al. 2018; Jiang et al. 2018; Smith et al. 2013; Wang et al. 2016; Ray et al. 2015; Chen et al. 2004; Iizumi and Ramankutty 2016; Olesen et al. 2011; Olesen and Bindi 2002; Alcamo et al. 2007; Olesen et al. 2011; Arata et al. 2020; Luo 2011; Chen et al. 2020). The results of these studies are implying that higher temperatures can reduce crop yields and increase yields variability. In some cases, for example in northern Europe, higher air temperatures can have a positive effect (Holmer 2008).

Climate change is influencing crop production by modifying the dynamics of diseases and pests, this is reflected in alterations in the distribution and population size of pests. A major influence on the abundance and distribution of pests and their threat to global crop production has been analysed (Pareek et al. 2017; Pareek et al. 2017; Prasad and Mukhopadhyay 2013; Saren et al. 2015; Roy et al. 2019; Sharma 2010). One of the side effects is an alteration in the effectiveness of pest management control, hence frequent treatment with pesticides will be needed and some of the commonly used pesticides have a negative effect on human health (Agostini et al. 2020; Sabarwal et al. 2018; Kumar et al. 2014; Roy et al. 2009; Kabir et al. 2018; Niehoff et al. 2016; Paul et al. 2016; Parrón et al. 2014; Fareed et al. 2013).

High concentrations of atmospheric CO2 are prone to have a direct impact on physiology, development, and nutritional composition in plants because plants are photosynthetic organisms. The positive effect of increased photosynthesis is enhanced growth, however, the negative effect is the decrease of the crop nutritional value in the term of mineral content in the grains (Mcgrath and Lobell 2013; Leisner 2020; Loladze 2014; Medek et al. 2017; Bisbis et al. 2018; Hogy and Fangmeier 2009; La Puente et al. 2000; Myers et al. 2014; Dietterich et al. 2015; Högy et al. 2010), also decreased of protein content has been observed (Medek et al. 2017; Leisner 2020; Taub et al. 2008; Abebe et al. 2016; Hogy and Fangmeier 2009; Fernando et al. 2012).

The agricultural practice contributes to climate change, every stage of food production releases significant quantities of greenhouse gases into the environment. It is estimated that agriculture releases 10% of the European Union's total greenhouse-gas emissions in 2012. One of the main objects of the new policy Agenda 2020 for the EU is to lower the negative environmental impact of EU farming (Vlontzos and Pardalos 2017).

The purpose of this chapter is to present these aspects of the negative effect of climate change on crop production and the potential influence on public health.

2 High Temperatures Altering Crop Yields

For each crop and every part of the growth development, a different range of temperatures can be determined. The outcome of enhanced temperature will depend on the optimal crop temperature for germination and reproduction.

The impact of global warming is certainly evident in crop production, yield responses to higher temperatures differ among different species depending on their optimum temperature for growth and development (Hatfield and Prueger 2015).

Scientific researches are indicated, with high confidence that global temperature will increase for more than 4 °C during the twenty-first century (IPCC 2014). The changes in the global temperature concurrently with water scarcity and severe weather conditions have a negative impact on every aspect of food safety. Also, the projected impacts are showing 25% of yield losses (Picture 2) compared to the end of the twentieth century (IPCC 2014).

Picture 2
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Review of forecasted changes in crop yields (wheat, maize, rice, and soy) due to climate change over the twenty-first century (IPCC 2014)

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Evaluation of the impact of global warming by 2 °C on wheat production presented that average yield on a global scale will be changed from − 2.4% to 10.5%, related to wheat production from the period of 1980–2010 (Liu et al. 2019). Following this information, we can observe a positive impact of climate change on annual yield, but this projection also suggested that extremely low yields will be frequent in regions with a warm climate and low precipitation, including India, which produces more than 14% of the wheat in the world (FAO 2014). A similar study was conducted in West Africa for maize, sorghum, and millet with the same predictions and conclusions (Parkes et al. 2018).

Assessment of climate change impact on the production of corn and soybean in Canada implied that higher temperatures would significantly reduce the yield of corn by 27% with just 4% reduce in soybean yield (Jiang et al. 2018). Additional studies with projected climate situations in Canada (Smith et al. 2013) and USA (Wang et al. 2016) observed that corn yields enhanced when cultivars with higher GGD (growing degree day) were planted.

The study of the influence of climate variation on wheat, maize, rice, and soybean crops yield on a global scale defined that nearly 32–39% of the changes in yield can be defined by climate variations (Ray et al. 2015).

A similar study was developed for major crops in the U.S. and the results showed that effects are differed by crop, for example, higher temperatures are reducing sorghum yields and yields variability and corn yields, but also increasing corn yield variability (Chen et al. 2004).

Global analysis of yield variability results showed that more than 21% of yield variation can be defined by climate change, these results also implied that yield worldwide has become unstable (Iizumi and Ramankutty 2016).

Higher air temperatures can also have a positive effect, in northern Europe yields are limited by low temperatures (Holmer 2008). A small increase in yield is apparent in the last 20 years in Finland, however, in Greece, the yields are decreasing (Olesen et al. 2011). Increases in the crop yield in Europe are expected in the northern region, but the significant decreases are expected in the Mediterranean and the south-western Balkans, especially for maize, soybean, and sunflower (Olesen and Bindi 2002; Alcamo et al. 2007).

It is obvious that crop production in Europe is affected by climate change, extreme temperatures in the central and southern Europe followed by drought has an adverse impact on crop yield and yield variability (Olesen et al. 2011).

Agriculture, food security, and policies are considerably affected by changes in crop yields and yield variability. Changes in climate and agricultural practices are mainly accountable for the increase in yield variability (Arata et al. 2020).

Acknowledging these studies it appears that there is an essential need to identify temperature optimum to estimate the effect of higher temperatures on crop production. Experimental studies, in the open field as well as under controlled conditions, can provide necessary information for more precise identification of higher temperature effects on crop production in every region (Luo 2011). For example, the productions of rice in China can be reduced by 13,5% due to climate change impact and higher air temperatures, but with changes in agricultural practices and policies these negative impacts could be partially avoided (Chen et al. 2020).

3 Impacts on Pest Management

The higher existence of pests and diseases is more pronounced while the temperature is increasing in the cooler zones, this effect is enabling insects to achieve more reproductive cycles (Bale et al. 2002). Climate change will enhance the development of diseases, weed and other pests accommodated to a warmer climate (Baker et al. 2000).

Climate change has a major influence on the abundance and pests distribution, therefore it poses a large threat to global agricultural production. Higher temperatures can likely raise levels of growth and potentially add one generation per year. This could influence the crop yield and change the effectiveness of pest management control, hence frequent application of insecticides will be needed (Pareek et al. 2017).

Some of the major impact of climate change on pests are also: different geographical distribution; more population of insects during winter; adjustment to other host plants; less resistance by host plants; different abundance of natural enemies; higher risk of invasive species of pests; the occurrence of more transmitted diseases by insects (Pareek et al. 2017).

Studies of the influence of climate change on tea insects indicate that their life cycle is shorter than expected (Prasad and Mukhopadhyay 2013; Saren et al. 2015), this has a positive effect on the population and causes more damage to crops.

With temperature rise, insects can reproduce more rapidly with the longer breeding season, this phenomenon leads to alteration in nutritional quality in plants, for example, more insects feed on plants so C:N ratio gets modified (Roy et al. 2019).

These impacts will have a significant effect on crop protection and safe food production. As a biological response to higher temperatures, all aforementioned effects will spread through all regions and influence all crops. It is necessary, through multidisciplinary cooperation (Picture 3), to achieve the monitoring of insect population and their adaptation, and to include effects of climate change in the development of improved pest management (Sharma 2010).

Picture 3
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Need for multidisciplinary cooperation (Young et al. 2019)

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Despite the existence of numerous effects of climate change on growth, distribution, and development of pests there is a lack of cross-collaboration between climate and pest management scientists and this leads to limited knowledge exchange between scientists (Young et al. 2019).

The use of pesticides for control of pests and disease and crop protection is inevitable in agriculture, however, pesticides are posing a threat to the environment and public health. For instance, it has been observed that the use of pesticides is causing in protected areas a severe decrease in the number of insects (Hallmann et al. 2017). Additionally, some of the frequently used pesticides have an accumulative negative effect on human health (Agostini et al. 2020).

It is estimated that pesticide poisoning accounts for 300,000 deaths in a year on a global scale (Sabarwal et al. 2018). Various health disorders are linked with exposure to pesticides, such as childhood leukemia (Kumar et al. 2014), prostate cancer (Roy et al. 2009; Kabir et al. 2018), breast cancer (Niehoff et al. 2016), Parkinson’s disease (Paul et al. 2016), Alzheimer’s disease and multiple sclerosis (Parrón et al. 2014), Respiratory disorders (Fareed et al. 2013).

4 Impact of High CO2 Concentration on Grain Quality

Plants are photosynthetic organisms, therefore elevated concentrations of atmospheric CO2 are prone to have a direct impact on physiology, development, and nutritional composition in plants (Ziska 2008).

Higher concentrations of CO2 have a stimulating consequence on plant growth because of increased photosynthesis (Müller et al. 2014). However, another effect is the reduction of the crops nutritional value in the term of mineral content in the seeds (Mcgrath and Lobell 2013; Leisner 2020).

Research on this effect, elevated atmospheric CO2, on wheat and rice indicated a decrease in total mineral content by 8% (Loladze 2014), and protein, Fe and Zn decreased by 3–17% (Medek et al. 2017; Leisner 2020).

A similar study observed a decrease in protein content in wheat, rice, and barley by 10–15%, in potato by 14%, and soybean by 1.4% (Taub et al. 2008). Another study with a similar experimental design showed a decrease in protein content in maize (11%) (Abebe et al. 2016).

Several studies including leafy vegetables on increased CO2 influence indicate higher content of sugars and vitamin C in edible parts of plants, while nutrients content decreased (Bisbis et al. 2018).

The study of the effects of elevated CO2 concentrations on the chemical content of potato tube showed increased content of glucose and fructose by 22% and 21% respectively, and decreased levels of proteins, potassium, and calcium (Hogy and Fangmeier 2009). Furthermore, a similar study observed lower protein content in wheat (13.4–15.3%) (Fernando et al. 2012).

Elements that are essential for our nutrition, such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), copper (Cu), magnesium (Mg), manganese (Mn), iron (Fe), zinc (Zn), and selenium (Se) (Smith et al. 2018) are found in grains. The impact of raised CO2 concentration on grain nutrient content differs within crops. For example, under the influence of higher concentrations of CO2 canola and wheat (Picture 4) have a lower content of N, however, this is not the case for field pea (Jin et al. 2019).

Picture 4
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Effect of elevated concentration of atmospheric CO2 on nutrient content in crop grain (Jin et al. 2019)

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Previous studies of this impact on wheat reported a reduction in the content of Fe and Zn in the grains (La Puente et al. 2000). More recent studies observed a reduction in nutrients content such as Ca, N, Fe, and Zn in the grains of soybean, sorghum, potatoes, wheat, and barley (Myers et al. 2014; Dietterich et al. 2015).

Spring wheat tested under a high concentration of CO2 revealed a reduction in Ca, Mg, and Mn by 9.7%, 4.2%, and 4.9% respectively (Högy et al. 2010). The same experiment showed an increase in K by 3.9%, P by 1.1%, and Fe by 1.2%.

According to Högy et al. decrease in macroelements is uniform for all wheat cultivar. Also, under experiment conditions with elevated CO2 concentration microelements content is decreasing from 3.7 to 18.3% (Senghor et al. 2017).

The higher concentration of atmospheric CO2 can cause more dietary deficiencies and create a global problem for public health. For example, the content of zinc in significant food crops can be lower, which is prompting dietary deficiency of zinc, on a global scale 2 billion people suffer this deficiency (Myers et al. 2014).

Nutrient deficiencies are more often in less-developed countries particularly concerning micronutrients (Schmidhuber et al. 2018), and the occurrence of anemia will increase since more people will suffer from protein and zinc deficiency (Smith and Myers 2018).

One of the many Sustainable Development Goals by the United Nations General Assembly (2015) is to enhance nutrition and limit all models of malnutrition by 2030 (Wu et al. 2020).

A study on a dietary nutrient deficiency of the population in China prognosticated decreases for both male and female intake of protein, zinc, and iron, as an outcome, the nutrient insufficiency would progress by 1.35–4.42% (Wu et al. 2020).

Other similar studies determined that the average change for the Chinese population in protein intake would be −4.91% (Medek et al. 2017), the iron intake will decrease by 3.8% (Smith et al. 2017), and zinc deficit will enhance by 0.6% (Myers et al. 2015).

The global prognosis is that the average profits of economic growth are higher than the adverse climate change impacts on macronutrient quantities, proteins included, though this prediction doesn’t apply to micronutrients (Nelson et al. 2018).

The reduction of CO2 emissions is a major challenge, hence it is needed to prevent degradation in crop nutrient quality (Wu et al. 2019).

5 Mitigation Strategies in Combating Climate Change Effects

Extreme temperatures followed by drought are showing a negative impact on crop yield and yield variability. Further, this negative impact is leading to increased irrigation, cultivation costs, and negative variations in soil and water quality (Dai et al. 2020; Gomez-Zavaglia et al. 2020). To achieve sustainable agriculture, and to reduce this adverse impact on crop yield, the best option is to breed crop varieties that are drought and temperature tolerant. With this approach, we can improve irrigation efficiency and achieve sustainable use of water for irrigation (Sofi et al. 2019).

Climate change has a significant impact on the effectiveness of pest management control, and on food safety, due to the frequent application of insecticides is needed. FAO advises the use of two simultaneous strategies with actions taken on both, global and local scale, this includes improvement of the system for control and detection, breeding of diseases and pest-resistant crop varieties, and implementing the integrated pest management systems (Sharma 2010). Additionally, a sustainable option is to adjust agricultural systems to enhance the activity of specific cultivation natural enemies and to explore the possibility to use biopesticides or natural essential oils as pesticides (Gomez-Zavaglia et al. 2020).

The essential part of mitigation strategies is the development of integrated monitoring in both sectors, environment, and food, to achieve the early identification of possible problems. Such systems can produce valuable data that can be easily shared on a national and international level and used to improve risk assessment. Adequate control tests are necessary at each step within food chain production to ensure food safety (Zwietering et al. 2010).

The government should provide policies and investment strategies to support education, demonstration training, and to raise awareness about climate change adjustment strategies, especially for smallholder farmers (Thinda et al. 2020).

Mitigation strategies have great success in developed countries, and adaptation options to fight against climate change are very similar on a global level. However, in developing countries, strategies that provide irrigation efficiency or improve crop management are limited.

6 Conclusion

Climate variability has a major influence on crop production, as temperature and CO2 are increasing quality and the quantity of crop production is decreasing. Evaluation of the impact of the global warming observed through recent studies presented that the most often result are yields decrease and yields variability increase.

Crop production is also very vulnerable to variation in the distribution and abundance of pests. One generation of insects per year as a result of higher temperatures are influencing crop yield and requiring a frequent application of insecticides. The more frequent use of insecticides has a strong negative effect on the environment and public health, hence different health complications are linked with exposure to pesticides. Understanding that the use of pesticides is inevitable in crop production it is essential to achieve multidisciplinary cooperation to implement the effects of climate change in the development of improved pest management.

The aforementioned studies observed that higher levels of CO2 in the atmosphere are affecting the nutritional value of crop grains. This impact has an important influence on safe food production, more dietary deficiencies are a potentially public health issue on a global scale.

Analysed three influences are among the most significant. Furthermore, there are impacts that we have not addressed, for example, soil microbe interaction under climate change and extreme weather conditions that can reduce access to food and price increases of a particular product. Additionally, it is crucial to analyse the sociological aspect and national security in the event of food deficiencies.