Read the news on any given day and you’re likely to find two themes: we are running out of water and we need more food for a growing population. A new study that is the first to quantify the possibilities of water management as it is related to increasing crop production examined current crop production levels and the potential effects of various water management strategies offers hope for increased production, but the numbers show that it’s not nearly what we will need.
The new study, supported by the EU ENSEMBLES project, is part of a larger investigation by the EU into the impact of climate change on water and agriculture. In essence, the study found that harvesting run-off water and reducing evaporation from soil could be combined to create a 20% increase in global crop production.
The Intergovernmental Panel on Climate Change ran model predictions and came up with a troublesome scenario: If the global population in 2050 is 10 billion we will need an additional 5000 km3 of water each year to produce enough food for everyone. With that in mind, they looked at what kind of water efficiency strategies we will need in the future.
The way the world irrigates now, we produce around 13.3 gigatons (Gt) of food. If we take that to mean just over 2 Gt of food per billion people is being produced right now, if our present population grows to 10 billion, we will need about 20 gigatons just to keep food production levels steady with what they are now.
The study estimated that a 25% reduction in evaporation could create 0.80 Gt more food, with semi-arid regions like the mid-west USA and Southern Africa having the best chance at increasing production.
Collecting 25% of runoff water could also increase food production by 1.52 Gt, with this increase having the most luck in tropical and wet regions like Central America and Brazil. The two strategies together could create about 2.50 Gt, or 20%, more food- not enough for the projected population increase.
The study also looked at how many people would be water-stressed by 2050 if the population rose to 10 billion. If a new global water management strategy could reduce evaporation by 25% and harvest an additional 25% of water runoff, water availability could fulfill food demand in most developed countries but not for countries in North Africa, the Middle East and South Africa.
Yes, that is as bad as it sounds. It means that 6 billion people, close to the population of the entire earth right now, will not have enough water to produce a healthy diet.
In short, we need to do as much as we can to increase water efficiency and management, and then come up with some even more innovative solutions to create healthy living conditions for the next generations.