Farming and Water
In Part 1 of Farming and ESG, we covered the challenges with stubble burning. In Part 2 we are now looking at water consumption. Farming feeds the world and employs over 30% of the global workforce. Unfortunately, this scale of production uses over 70% of the world’s freshwater supply.
All crops need water; however, some crops have far higher demands. Rice requires huge volumes of water, over 2,500 litres per kilo of rice, about 10 times that of potatoes. However, even “inefficient” rice is far more efficient when compared to nuts (almonds, pistachios, etc.). Nuts require around 15,000 litres of fresh water to produce a single kilo of nuts. This is 30 to 60 times more than potatoes.
To put this into scale: California nut production consumes around three times as much water as the whole of Los Angles.
The table below gives examples of some of the most well-known crops
|Crop||Litres of Water Required per Kg of Crop (Low)||Litres of Water Required per Kg of Crop (High)|
|Almonds (in California)||14,000||16,000|
Water v Calories v Complexity
While overconsumption of water is a challenge, with climate change and increased droughts, it is a far more complex issue than simply “more water is bad”. Understanding farming and water consumption require comparing many complex factors, including the source of the water and the comparative calorie production.
For example, a litre of water from Wales (known for its rain) is less of an issue than a litre of rain in California, which suffers droughts. Calorie production is another important factor. While nuts consume huge amounts of water, they also produce high calories – around ten times more calories per kg than potatoes.
What I’m worried about is that if there isn’t sound science under [how companies are judged] we’re going to make a lot of big mistakes along the way,” he says. “This isn’t tobacco where we just want to get rid of a product. This is really complicated . . . If the changes aren’t science-based we could not do any good or we could even do harm.” – Dariush Mozaffarian, dean of the Tufts University Friedman School of Nutrition, Science and Policy in Boston
For this reason, its very important to look at not just the input (the water) but the output (the calories).
It’s also important to understand the nature of water availability. For example – high water demand crops, like nuts, are more of problem ins sunny California than they are in wet Wales….but there is a reason there are no cashew farms in Wales.
Remote sensing can measure the quality of water (this will be covered in a later episode) and is also being used to look at water management, but there are still challenges with this method.
This article covers water management in detail, and is a meta study of the different methods.
A few key points from this article
- The overwhelming majority of agricultural water use worldwide remains unmetered.
- A key factor for low levels of metering is incomplete records and technical challenges of implementation.
- In surface water irrigation systems, illegal off-takes from canals or rivers are common.
- Growing body of research exists that seeks to leverage satellite remote sensing
- A review of over 1,000 pages, and 40+ in detail found that the remote sensing for water management are not yet accurate enough
While there is no simple solution yet, a lot of research and effort are being directed to tackle this issue – which reflects the overall complexity.