7
(Elsaeed 2012). Moreover, as a result of sea level rise, intrusion of saline water in
low coastal areas could occur, which will influence the quality of fresh water aquifers (Bates et al. 2008). The combined effect of higher temperature and the reduction
of water availability in regions affected by falling precipitation could result in an
increase of crop evaporative demands, following by reduction in crop yield, where
temperature restrains crop growth (FAO 2005).
The UNEP (2013) reported that climate change will affect the extent and productivity of both irrigated and rain fed agriculture across the globe, increasing crop
water demand and decreasing crop productivity in many regions. FAO (2012) predicted that by 2030, the world population will grow beyond 7.5 billion inhabitants,
which will have a significant impact on water usage for food. They also predicted
that food demand will increase by 50% and water use in irrigation will increase by
30%. In Egypt, Alkitkat (2017) projected that the Egyptian population in 2030 will
increase by 32%, compared to the population value recorded in 2014. Accordingly,
the demand for food is expected to increase. For example, the demand for wheat is
expected to increase by 53% (Ouda and Zohry 2017), for maize by 40% (Zohry and
Ouda 2017a) and for faba bean by 68% (Zohry and Ouda 2017b). Furthermore, de
Fraiture and Wichelns (2010) indicated that, under a pessimistic low yield scenario
in 2050, water consumption by the crops will increase by 53% and lands needed to
achieve food production goals will increase by 38%.
1.6 Climate Change and Agricultural Soil
Soils has a major role in supplying macro and micro nutrients to all kinds of crops
grown in it, thus they are important for food security. Because climate is one of the
most important factors affecting the formation of soil, climate change could result in
soil deterioration (Karmakar et al. 2016) and consequently it has the potential to
threaten food security through its effects on soil properties and processes (Pimentel
2006). Increased temperature is likely to have a negative effect on carbon allocation
to the soil, leading to reductions in soil organic carbon and creating a positivefeedback in the global carbon cycle (Wan et al. 2011). Increased temperatures lead to
increased carbon dioxide release from soils to the atmosphere leads to more increases
in temperature (Cole et al. 2018). Rising atmospheric carbon dioxide levels, elevated
temperature, altered precipitation and atmospheric nitrogen deposition caused by climate change, affect soil chemical, physical and biological functions (IPCC 2007).
A decline in soil organic matter levels lead to a decrease in soil aggregate stability, infiltration rates and increase in susceptibility to compaction, run-off and susceptibility to erosion (Gorissen et al. 2004). Furthermore, increased salinization and
alkalization would occur in areas where evaporation increased or rainfall decreased
(Varallyay 1994). Transient salinity increases as capillary rise dominates, bringing
salts into the root zone on sodic soils. Increased subsoil drying increases concentration of salts in the soil solution. Conversely, the severity of saline scalds due to
1 Water Scarcity Leads to Food Insecurity
(Elsaeed 2012). Moreover, as a result of sea level rise, intrusion of saline water in
low coastal areas could occur, which will influence the quality of fresh water aquifers (Bates et al. 2008). The combined effect of higher temperature and the reduction
of water availability in regions affected by falling precipitation could result in an
increase of crop evaporative demands, following by reduction in crop yield, where
temperature restrains crop growth (FAO 2005).
The UNEP (2013) reported that climate change will affect the extent and productivity of both irrigated and rain fed agriculture across the globe, increasing crop
water demand and decreasing crop productivity in many regions. FAO (2012) predicted that by 2030, the world population will grow beyond 7.5 billion inhabitants,
which will have a significant impact on water usage for food. They also predicted
that food demand will increase by 50% and water use in irrigation will increase by
30%. In Egypt, Alkitkat (2017) projected that the Egyptian population in 2030 will
increase by 32%, compared to the population value recorded in 2014. Accordingly,
the demand for food is expected to increase. For example, the demand for wheat is
expected to increase by 53% (Ouda and Zohry 2017), for maize by 40% (Zohry and
Ouda 2017a) and for faba bean by 68% (Zohry and Ouda 2017b). Furthermore, de
Fraiture and Wichelns (2010) indicated that, under a pessimistic low yield scenario
in 2050, water consumption by the crops will increase by 53% and lands needed to
achieve food production goals will increase by 38%.
1.6 Climate Change and Agricultural Soil
Soils has a major role in supplying macro and micro nutrients to all kinds of crops
grown in it, thus they are important for food security. Because climate is one of the
most important factors affecting the formation of soil, climate change could result in
soil deterioration (Karmakar et al. 2016) and consequently it has the potential to
threaten food security through its effects on soil properties and processes (Pimentel
2006). Increased temperature is likely to have a negative effect on carbon allocation
to the soil, leading to reductions in soil organic carbon and creating a positivefeedback in the global carbon cycle (Wan et al. 2011). Increased temperatures lead to
increased carbon dioxide release from soils to the atmosphere leads to more increases
in temperature (Cole et al. 2018). Rising atmospheric carbon dioxide levels, elevated
temperature, altered precipitation and atmospheric nitrogen deposition caused by climate change, affect soil chemical, physical and biological functions (IPCC 2007).
A decline in soil organic matter levels lead to a decrease in soil aggregate stability, infiltration rates and increase in susceptibility to compaction, run-off and susceptibility to erosion (Gorissen et al. 2004). Furthermore, increased salinization and
alkalization would occur in areas where evaporation increased or rainfall decreased
(Varallyay 1994). Transient salinity increases as capillary rise dominates, bringing
salts into the root zone on sodic soils. Increased subsoil drying increases concentration of salts in the soil solution. Conversely, the severity of saline scalds due to
1 Water Scarcity Leads to Food Insecurity