Nutritious and safe food supply is a vital component of food security. Climate change will directly impact food availability throughout the food value chain, affect the ability of food to move from production to markets. Agriculture activities will hit hard due to its sensitivity to the climate, and therefore decrease access to adequate nutrient-dense foods that impaired nutritional status by consequently affect human diets and nutrition (Secretariat, 2010). Food nutrition will be affected by reducing crop yield, decrease dietary diversity, and reduces nutritional food content (Fanzo, Davis, McLaren, & Choufani, 2018).
An increase in atmospheric CO2 will affect the nutritional value (minerals and protein) for cereals, legumes, fruits, and vegetables (Soares, Santos, Carvalho, Pintado, & Vasconcelos, 2019). The impact is extended to C3 grains and legumes that are the primary dietary source of zinc and iron for most people. It will cause a substantial global public health problem causing loss of 63 million death annually by 2050. C3 crops will be more affected than legumes with fewer concentrations of protein, whereas C4 crops will be affected less. (Myers et al., 2014).
Predicted 550ppm of atmospheric CO2 in 2050 will reduce protein, iron, and zinc concentration of staple food crops by 3 to 17% and affect a significant extent, population that relies on vegetal sources for nutrients, mostly rural population in South & East Asia and Sub Saharan Africa. There will be an additional 175 million people to be zinc deficient, 122 million people to be protein deficient, and 1.4 billion women of childbearing age and children under 5 with greater than 20% anemia prevalence and would lose >4% of dietary iron (Smith & Myers, 2018). There are significant interactions between climatic factors and soil availability of nitrogen, potassium, iron, and phosphorous (Soares et al., 2019).
Climate change will cause an increase in temperature and heat waves that is predicted to become more intense, frequent, and longer-lasting (Lake et al., 2012), expected to cause 95 000 deaths (WHO, 2014). The heat will exacerbate food shortage and affect nutrition, but exposure to extreme heat stress will cause dehydration, organ damage, and fatigue (McMichael & Lindgren, 2011). The high temperature will as well impact food security by increasing the incidence of drought and crop failure as the majority of farmers rely on rainfall for crop cultivation.
Climate change will increase the frequency and duration of drought that will pose adverse effects on agricultural productivity, reduce soil fertility, and the ability of crops to acquire and utilize soil nutrients, intensify food insecurity (Clair & Lynch, 2010). (Hummel et al., 2018) demonstrated that both nutritional quality and the growing area would be reduced in Africa for biofortified beans, under future climate change-induced drought stress scenarios. In particular, they found that iron levels in common bean grains are reduced under future climate-scenario relevant drought stress conditions. In contrast, protein, zinc, lead, and phytic acid increase in the beans under such drought stress conditions. This indicates that under climate-change-induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality. Additionally, drought can increase and modulate the ionic composition of grain in crops (Etienne et al., 2018). On the contrary, provitamin A carotenoid in maize grains is found not to be affected by stress like low soil nitrogen and drought, with a negative correlation detected between grain yield and proVA carotenoids (Ortiz‐Covarrubias et al., 2019)
The inoculated plants showed significant tolerance to drought stress. The seleno-bacteria enhanced the effect of AM fungus in controlling the antioxidant systems that play a role as elicitors of plant drought responses and improving the nutritional quality and physiological and biochemical processes involved in plant drought tolerance (Durán et al., 2016).
Extreme weather events affect the supplies of Micronutrient globally. Excess rainfall and extreme temperature increase the disruption of food distribution by damaging infrastructure or delay shipment and increase the risk of the food damage, spoilage and contamination, therefore limit availability access to safe and nutritious food (Ziska et al., 2016). The effect of extreme events realized more among landlocked developing countries (ranging from 1·95 to 39·19% of what a healthy child’s sufficient average dietary intake should be) and low-income food-deficit countries with significant nutrient supply changes ranging from −1·61 to −7·57% of the average supply. Calcium, folate, thiamin, vitamin B6, and vitamin C can have higher significant levels (Park et al., 2019). Extreme events are likely to introduce contaminants in the food value chain that will affect the nutritional value of food (Ziska et al., 2016). Moreover, it will significantly increase the incidence of diseases like diarrhea and weight for height malnutrition that affect children below three years (Wang, Kanji, & Bandyopadhyay, 2009) and increase of exposure of food to certain pathogens and toxins that will increase the use of pesticides and adversely increase health impact (Ziska et al., 2016).