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As the world's population increases, food and water resources will be ever more strained. By 2050, we will need to feed a population of nine billion people, two billion more than today. The UN Food and Agriculture Organisation (FAO) estimates that farmers will have to produce 70% more food by 2050 to meet the needs of the world's expected 9-billion-strong population. That amounts to 1bn tons more wheat, rice and other cereals and 200m more tons of beef and other livestock.
(General Problem)
(Farmland not increasing)
The amount of land available for farming is not going to increase.
But as it is, most available farmland is already being farmed, and in ways that decrease its productivity through practices that lead to soil erosion and wasting of water.
This means that to meet the world's future food needs, a major "sustainable intensification" of agricultural productivity on existing farmland will be necessary, the FAO said in its report, State of the World's Land and Water Resources for Food and Agriculture.
(Climate is changing)
More climate uncertainty --> more risk in crop production
Climate change, including climate variability, has a direct impact on water availability and irrigation. Notably the loss of ground and surface water, as well as increases in evapotranspiration will place greater stress on the limited availability of fresh water. (Connor J, Schwabe K, King D, Kaczan D, Kirby M (2009) Impacts of climate change on lower Murray irrigation. Australian Journal of Agricultural and Resource Economics 53: 437–456.)Multiple studies have concluded that climate change will have an impact on water availability for agriculture. Notably the loss of ground and surface water, as well as increases in evapotranspiration will place greater stress on the limited availability of fresh water. (Connor J, Schwabe K, King D, Kaczan D, Kirby M (2009) Impacts of climate change on lower Murray irrigation. Australian Journal of Agricultural and Resource Economics 53: 437–456.)
Data on water withdrawals for US states (1985–2005) show that both climate change and resulting water deficits are highly positively correlated with moisture deficit (precipitation - PET). If current trends hold, climate change would increase agricultural demand for irrigation in 2090 by 4.5 -21.9 million ha. Without significant increases in irrigation efficiency, climate change would also increase the average irrigation rate from 7,963 to 8,400–10,415 m3ha.
(McDonald RI, Girvetz EH (2013) Two Challenges for U.S. Irrigation Due to Climate Change: Increasing Irrigated Area in Wet States and Increasing Irrigation Rates in Dry States. PLoS ONE 8(6): e65589. https://doi.org/10.1371/journal.pone.0065589)
(General Problem)
(Farmland not increasing)
The amount of land available for farming is not going to increase.
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More climate uncertainty --> more risk in crop production
(Irrigation is important)
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