Trillions of cubic meters of water is used to grow crops each year
Ever wondered how much water it takes for humans to cultivate the world’s primary crops? A recent study illuminates some startling numbers.
Our demand for water keeps increasing, despite our improved ability to grow more food with less water. This escalating demand could lead to a cluster of environmental and socio-economic problems.
Water footprint of crops
The research, led by experts from University of Twente, scrutinized the water footprints of 175 crops spanning from 1990 to 2019. What’s a water footprint? Simply put, it’s the amount of water used in the production process.
This study separated water into two types – green and blue. The green kind comes from rainfall, while the blue kind is derived from irrigation and groundwater.
“We need to differentiate between these two water types as they play different roles in ecosystems and society,” said Oleksandr Mialyk, a postdoctoral researcher at the Multidisciplinary Water Management group.
On a brighter note, the study revealed that around 80% of the scrutinized crops in 2019 required less water per ton than they did in 1990. So, we have become better at using less water to produce more food.
Surge in water usage for crops
Sadly, the productivity rise hasn’t stopped the overall water footprint of crop production from inching higher. Since 1990, it surged by nearly 30%, or 1.55 trillion m3 (That’s roughly 410,132 billion gallons).
“Our estimate for 2019 stands at 6.8 trillion m3 of mainly green water, which is around 2,400 liters per person per day,” said Mialyk.
The most surprising part? A whopping 90% of the total increase happened between 2000 and 2019.
More crops, more water
So, what sparked this rise? The researchers highlight three significant socio-economic factors. First, our fast-paced globalization and economic growth have notably amplified our consumption of a variety of imported crops and crop products.
In addition, there has been a shift in our global diets towards more water-guzzling products like animal produce, sweetened beverages and junk food.
Finally, many government efforts to secure energy and promote green initiatives have increased the production of crop-based biofuels.
Versatility in water consumption of crops
Interestingly, these socio-economic shifts have mainly boosted the cultivation of “flex crops.” These crops can be transformed into a myriad of products such as food, animal feed, and biofuels.
This flexibility gives farmers, investors, and insurers a safety net, reducing financial risks linked to crop production.
Over the last few decades, largely thanks to aggressive agricultural lobbyism, the production of these flex crops has rapidly shot up.
The three biggest ones – oil palm fruit, soya beans, and maize (corn for many of us) – account for half the total water footprint increase of crop production from 1990–2019.
Water-guzzling nations
India, China, and the United States are the biggest water consumers. But, the total water footprint increase has primarily happened in the tropics, often coupled with other environmental impacts like deforestation and biodiversity loss.
“This region offers optimal geographical conditions for crop production while favorable agricultural policies attract investments from large agrifood corporations,” explained the researchers.
Environmental implications of the study
The intricate relationship between water usage and agriculture bears considerable environmental consequences. Extensive water consumption, primarily of green water, often results in diminished natural resources, ecosystem disruptions, and heightened groundwater depletion.
These effects lead to losses in biodiversity and degradation of local habitats, which are often difficult to reverse. Furthermore, increased reliance on irrigation can exacerbate soil salinity and reduce soil fertility, posing severe long-term challenges to sustainable agriculture.
An understanding of these environmental implications is crucial for developing effective water management strategies to ensure future agricultural sustainability.
Increasing water use for crops
“Our data suggests that humanity will keep increasing water consumption for crop production in the following decades,” said Mialyk.
However, all hope isn’t lost. The researchers believe that there remains a lot of untapped potential in improving crop water productivity and shifting production to less water-scarce areas.
Moreover, a broader adoption of less water-intensive diets and minimizing the reliance on first-generation biofuels could also help.
“”Our research shows that we have many problems and now it is time to work on the solutions for a more water-sustainable future of crop production,” concluded Mialyk.
The study is published in the journal Environmental Research Letters.
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