Overpopulation and water scarcity leading to world future food crisis

| July 12, 2020 | Leave a Comment

small vegetable garden

Author(s): Gioietta Kuo


The future of our food supply should undoubtedly be the number one concern of our world today.   What affects this future food supply?  It is well known that the world is already overpopulated today at 7.7 billion and is predicted to have 9.7 billion  in 30 years time in 2050.  This is destined to happen irrespective of what measures we take today.  Only after 2050 may we expect a leveling off if we adopt sensible steps[1].   


Apart from food, water is the other essential element for our existence,   Water is consumed throughout the food production process, from growing the animal’s food and the drinking water animals drink, to the overall meat production process.

To produce enough food to sustain the planet’s population, it is estimated that 52,8 millions of water per second are required [2]  Of our total water consumption, food accounts for roughly 66%.   It is ubiquitously hidden in everything we consume.  For example one needs

  • 240 gallons of water to produce a loaf of bread
  • 46  gallons to produce a soda
  • 12 gallons for a serving of potato chips
  • 108 gallons to produce a gallon of tea from planting
  • 1956 gallon to produce  coffee
  • 872 gallons for one gallon of wine and 296 gallons for one gallon of beer
  • Subsidiary products like eggs requires 496 gallons ,  a pound of cheese requires 483 gallons and a pound of butter  665 gallons 122 gallons for 2 pints of milk 
  • other items like fruit juice requires gallons of water   

According to a UN water scarcity report[3]  over 2 billion people live in countries experiencing high water stress.  It is estimated that by 2040  some 600 million children will be living in areas of extremely high water stress   leading to maybe 700 million people being displaced worldwide.  

Typical values for the volume of water required to produce common foodstuffs [4]

Foodstuff Quantity Water consumption, litres
Chocolate 1 kg 17,196
Beef 1 kg 15,415
Sheep Meat 1 kg 10,412
Pork 1 kg 5,988
Butter 1 kg 5,553
Chicken meat 1 kg 4,325
Cheese 1 kg 3,178
Olives 1 kg 3,025
Rice 1 kg 2,497
Cotton 1 @ 250g 2,495
Pasta (dry) 1 kg 1,849
Bread 1 kg 1,608
Pizza 1 unit 1,239
Apple 1 kg 822
Banana 1 kg 790
Potatoes 1 kg 287
Milk 1 x 250ml glass 255
Cabbage 1 kg 237
Tomato 1 kg 214
Egg 1 196
Wine 1 x 250ml glass 109
Beer 1 x 250ml glass 74
Tea 1 x 250 ml cup 27
Source: IME



Although in principle enough food is produced around the world to feed more than enough  the global population.  But according to Unicef 2019 [5] more than 820 million people go hungry each year.

Factors which contribute to hunger are  strongly related to  overpopulation and poverty. This involves interactions among an array of social, political, demographic, and societal factors. People living in poverty frequently face household food insecurity, use inappropriate care practices,  live in unsafe environments that have low access to quality water, low sanitation,  hygiene, and inadequate access or availability to health services and education. Conflict is also a key driver of severe food crises.  This includes famine—a fact officially recognized by the UN Security Council in May 2018[3]4 . Hunger and undernutrition are much worse when conflicts are prolonged and political  institutions are weak.  Unfortunately the number of conflicts is on the rise today,  worsened by climate change.  Some  have also impacted food availability in many countries and thus contributed to the rise of food insecurity. 

This underscoring the immense challenge of the UN Zero Hunger target by 2030.  Hunger is on the rise in almost all African subregions leading to Africa having the highest prevalence of undernourishment in the world.  The Unicef report calls for actions to safeguard food security and nutrition through economic and social policies that counteracts slowdowns,  providing social safety nets and ensuring universal access to health, education, and contraception.   Basically one should tackle inequalities to ensure sustainability at all levels of society.

Overpopulation increases uncontrolled urbanization and expansion of cities leading to more infrastructure and using up of resources.    At the same time,  this increases carbon dioxide emission Into the atmosphere resulting in more climate change.  It is  imperative to reduce fossil fuel, adopt alternative renewable energy and nuclear power.



How Many People Can It Support?

According to Harvard’s food expert Edward O. Wilson if everyone became vegetarian then the carrying capacity could be 10 billion as far as food is concerned. 

Already we have hit a limit in measuring the ecological footprint of this burgeoning population – the amount of biologically productive land and water a person requires for producing the resources it consumes.  

According to the UN food and agriculture organization, 11% of our land surface is being used for growing crops.  An even bigger area is being employed for livestock grazing since water is essential for the food we produce.  

We have to feed more than 9.7 billion people in less than 30 years.  This is an increase of 25% from the current population.  Yet many say we need to produce may be 35% in food. This estimate highlights a stark challenge for the global food system. The world is getting richer, especially the developing  populous countries of China and India. There is a demand for eating high protein meat products.  In China pork is the much preferred meat.  While India remains a predominantly a vegetarian nation,   there is a growing demand for beef and seafood in coastal regions.

According to the World Wildlife Fund, water used for livestock production is expected to rise by 50 per cent by 2025 and at present it accounts for 15 per cent of all irrigated water.

The global average water footprint of beef is 15,400 liters per kilo, which is predominantly green water – water from renewable sources – (94 percent).

The water footprint related to animal feed takes the largest share with 99 percent of the total consumption, while drinking and service water contribute just one per cent to the total water footprint.

However, drinking water is 30 percent of the blue water footprint.

To achieve this life satisfaction for the ever increasing population will demand  a constraint on economic social governmental policies.

According to the United Nations, water use has grown at more than twice the rate of population increase in the last century. By 2025, an estimated 1.8 billion people will live in areas plagued by water scarcity, with two-thirds of the world’s population living in water-stressed regions as a result of use, growth, and climate change. The challenge we now face as we head into the future is how to effectively conserve, manage, and distribute the water we have not only in the US but across the globe. In fact,  agricultural withdrawals account for 69% of water use around the world.

The food crisis is more complex and National Geographic has published an excellent article highlighting 5 necessary steps for managing the future food crisis [ 6]. We list here briefly the 5 steps to follow:

  1. Increase agriculture.  Agriculture is among the greatest contributors to global warming.  It  has cleared  forests and grasslands and reduced biodiversity, There are 2 concepts as to how to manage and control  agriculture. Conventionally we use modern mechanization on a large scale, with irrigation, fertilizers, pesticides and modern genetics in seeds.  This method should increase yields.   The  other concept is based on local and organic farms  which increase demands and help themselves out of poverty  – by adopting techniques that improve fertility without synthetic fertilizers and. pesticides.

Industrial agriculture, along with subsistence agriculture, is the most significant driver of deforestation in tropical and subtropical countries, accounting for 80% of deforestation from 2000-2010. Upward of 50,000 acres of  forests  are cleared by farmers and loggers per day worldwide and a large part is   destroyed in the Amazon basin.  This extreme clearing of land, especially for animal agriculture, results in habitat loss, amplification of greenhouse gases, disruption of water cycles, increased soil erosion, and excessive flooding.

The current contribution of agriculture to deforestation varies by region, with industrial agriculture being responsible for 30% of deforestation in Africa and Asia, but close to 70% in Latin America. The most significant agricultural drivers of deforestation include soy, palm oil, and cattle ranching.We have already cleared an area the South America to grow crops.  And to raise livestock an area the size of Africa.    So we can no longer afford to increase food production through agriculture expansion.  In fact most of agriculture is used to produce cattle, soybeans for livestock, timber and palm oil.  We must avoid further deforestation. Industrial farming has already used you large tracts of land.  We should look to organic farming on smaller plots with individual farmers which not only increase yields but left themselves out of poverty.

    1. Grow more on the farms we have 

In Africa, Latin America and Eastern Europe,  we can try to increase yields on less productive farmlands by using high tech precision farming systems.  With techniques   taken from organic farming, such as computerized weather forecasting, exact matching of fertilizers to the soil, drip feeding irrigation  and etc,     we can boost yields by several times.

  1. Use resources more efficiently

Today’s commercial farming has started to make huge strides, finding innovative ways to better target the application of fertilizers and pesticides by using computerized tractors equipped with advanced sensors and GPS. Many growers apply customized blends of fertilizer tailored to their exact soil conditions, which helps minimize the runoff of chemicals into nearby waterways.

Organic farming can also greatly reduce the use of water and chemicals—by incorporating cover crops, mulches, and compost to improve soil quality, conserve water, and build up nutrients. Many farmers have also gotten smarter about water, replacing inefficient irrigation systems with more precise methods, like subsurface drip irrigation. Advances in both conventional and organic farming can give us more “crop per drop” from our water and nutrients.

4. Shift diets  Why is it that to feed an extra 25%  of populations in 2050 we are talking about increasing food production by 50-100 %?  It is because today only 55% of the world’s crop calories feed people directly, the rest are fed to livestock( about 36%) or turned into biofuels and industrial products ( around 9%).  For every 100 calories of grain we feed animals, we get only 40 new calories of milk, 22 calories of eggs, 12 of chicken, 10 of pork and 3 of beef.  Finding more efficient ways to grow meat and shifting to less meat intensive diets could free up a large number of food for the world.   See the previous chapter on the Earth’s carrying capacity and shifting to diets using less water.  As we have mentioned,  the world is getting richer,  especially developing countries in China and India.  There is a growing demand for high calorie meats.   A shift to soybean based diets would  better provide for the world’s overpopulation. 

5.  Reduce waste

Between 500 and 4,000 liters of water are required to produce 1kg of wheat.  According to the UK Institution of Mechanical Engineers(IME) [4], as much as 2 billion tonnes of  food are wasted every year – equivalent to 50% of all food produced.  This means  30-50% (1.2 – 2 billion tonnes) of total food produced every year is lost before reaching a human mouth.  In poor countries food is often lost from the farmer  due to unreliable storage and transportation.  Of all the steps for increasing food for mouths to feed, surely reducing waste  is the most direct and effective way?

The publication entitled ‘Global food: waste not, want not’ also aims to highlight the wastage of energy, land and water. Approximately 3.8 trillion cubic meters of water is used by humans annually with 70% being consumed by the global agriculture sector. The amount of water wasted globally in growing crops that never reach the consumer is estimated at 550 billion  cubic meters.

IME claim that water requirements to meet food demand in 2050 could reach between 10-13.5 trillion cubic meters per year – about triple the current amount used annually by humans. 


In sum,  there is a limit to large scale conventional industrialize farming.   We should. use more organic farming using modern techniques of weather forecasting, sensors, GPS,  matching of fertilizers to soil, subsurface drip irrigation  and prevent runoff. 

Most of all, we should reduce waste which at the moment is half what the world produces. 

The  National Geographic in its article [6} on feeding 9 billion has produced many succinct ideas.in how to overcome the impending future food crisis for the planet. Its conclusion is excellent.  We are living at a pivotal moment in history.   So far, in history we have adopted the philosophy of more and more food to feed the growing overpopulation.   This we do by deforestation and increasing agriculture.  But time has come for serious reflection.    We cannot continue on this route.  We have to change our mind set –   To eliminate the vast food wastage at the same time to switch to a more vegetarian diet to release the pressure on meat eating.   Most importantly   we should improve   our food security worldwide –  to mitigate  the source of our crisis  – overpopulation and water scarcity.



[1]  Growing Global Overpopulation and Migration are Destabilizing our World,   Gioietta Kuo, 


[2]. Food and Water: How Much is Needed to Produce Our Food …

[3] https://www.unwater.org/water-facts/scarcity/

 World Water Development Report 2020 | UNWater

[4]  How much water is needed to produce food and how much do …
https://www.theguardian.com/news/datablog/2013/jan/10/how-much-water-food-production-waste Jan 10, 2013 Meat production requires a much higher amount of water than vegetables. IME state that to produce 1kg of meat requires between 5,000 and … 

[5] World Hunger, Poverty Facts, Statistics 2018 – World Hunger
The state of food security and nutrition in the world 2019 …



[6[  Feeding 9 Billion | National Geographic 


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