304
A warmer climate will increase water demand in most cases. Impacts will be
more significant where water is already scarce, infrastructure poor, and populations
are increasing rapidly. However, there are significant opportunities to increase the
efficiency of water use and adopting practices such as water reuse that will reduce
adverse impacts on human populations. Also, a variety of climate impacts on water
infrastructure (Chap. 10) are likely including natural water capture and storage by
ecosystems (Chap. 9), extreme events damaging reservoirs, dams, aqueducts, drinking water treatment plants, pipes, and wastewater treatment plants.
11.4.1.3 Climate Change Impacts on Water for Food
Agricultural productivity will be impacted both directly by climate change (see
Sect. 11.4.2 below), through impacts on first order interactions of food-systems
with water, and through impacts on higherorder system interactions.
Changes in the earth’s hydrologic cycle will impact the supply of water to crops
from rainfall and soil moisture. Such changes will change the demand for water via
irrigation. Demand for irrigation is expected to increase in many areas such as the
USA, Europe, and parts of Asia, while some areas may see reduced demand for
irrigation, such as South Asia and parts of China. The availability of water for irrigation can mitigate the drop in agricultural productivity associated with agricultural
droughts during meteorological droughts. However, water availability for irrigation
depends on water storage in natural locations like aquifers or reservoirs and on
infrastructure and energy to move water from storage sites to fields.
As already noted, climate change will intensify the earth’s hydrologic cycle and
create greater variability in precipitation in most areas. The impact of this on food
production will depend on many factors, including the level of damage from intense
rainfall, soil characteristics, infrastructure, the likelihood of flood, and actions to
balance water supply and demand. Drying will be particularly pronounced in the
subtropics, the portion of the globe between the wetter tropical regions and midlatitude regions (typically 23° to 35° latitude). This will result in significant impacts
on irrigation water supply also effects on groundwater depletion in such locations as
northern Mexico, southern USA, northern and southern Africa, northern India, and
larger areas of China and Australia.
Most intense rainfall may lead to more soil erosion, reduced soil depth, and
degradation of fertility. This may further impact water quality for other uses.
Of course, greater efficiency in agricultural water use through better management
and technological innovation can reap benefits separate from climate change impacts.
11.4.1.4 Climate Change Impacts of Water for Energy
The world’s energy systems are currently dominated by fuels that utilize large volumes of water in production and use. For example, fossil fuels, which provided 81%
of the world’s Total Primary Energy (TPE) in 2015 (IEA 2017), have considerable
water demands.
P. Saundry
A warmer climate will increase water demand in most cases. Impacts will be
more significant where water is already scarce, infrastructure poor, and populations
are increasing rapidly. However, there are significant opportunities to increase the
efficiency of water use and adopting practices such as water reuse that will reduce
adverse impacts on human populations. Also, a variety of climate impacts on water
infrastructure (Chap. 10) are likely including natural water capture and storage by
ecosystems (Chap. 9), extreme events damaging reservoirs, dams, aqueducts, drinking water treatment plants, pipes, and wastewater treatment plants.
11.4.1.3 Climate Change Impacts on Water for Food
Agricultural productivity will be impacted both directly by climate change (see
Sect. 11.4.2 below), through impacts on first order interactions of food-systems
with water, and through impacts on higherorder system interactions.
Changes in the earth’s hydrologic cycle will impact the supply of water to crops
from rainfall and soil moisture. Such changes will change the demand for water via
irrigation. Demand for irrigation is expected to increase in many areas such as the
USA, Europe, and parts of Asia, while some areas may see reduced demand for
irrigation, such as South Asia and parts of China. The availability of water for irrigation can mitigate the drop in agricultural productivity associated with agricultural
droughts during meteorological droughts. However, water availability for irrigation
depends on water storage in natural locations like aquifers or reservoirs and on
infrastructure and energy to move water from storage sites to fields.
As already noted, climate change will intensify the earth’s hydrologic cycle and
create greater variability in precipitation in most areas. The impact of this on food
production will depend on many factors, including the level of damage from intense
rainfall, soil characteristics, infrastructure, the likelihood of flood, and actions to
balance water supply and demand. Drying will be particularly pronounced in the
subtropics, the portion of the globe between the wetter tropical regions and midlatitude regions (typically 23° to 35° latitude). This will result in significant impacts
on irrigation water supply also effects on groundwater depletion in such locations as
northern Mexico, southern USA, northern and southern Africa, northern India, and
larger areas of China and Australia.
Most intense rainfall may lead to more soil erosion, reduced soil depth, and
degradation of fertility. This may further impact water quality for other uses.
Of course, greater efficiency in agricultural water use through better management
and technological innovation can reap benefits separate from climate change impacts.
11.4.1.4 Climate Change Impacts of Water for Energy
The world’s energy systems are currently dominated by fuels that utilize large volumes of water in production and use. For example, fossil fuels, which provided 81%
of the world’s Total Primary Energy (TPE) in 2015 (IEA 2017), have considerable
water demands.
P. Saundry