THINKING OF making the switch to non-dairy 'milks to save the planet? Not so fast!

Leaving aside the whole debate about whether liquids squeezed out of nuts and pulses can legitimately be called 'milk' at all, some scientists are warning that the extraction process may not be environmentally sustainable because of its high water use.

Dietary trends and concerns about animal welfare have all contributed to the recent prominence of dairy alternatives, in particular milk substitutes, while dairy consumption in the UK, per capita, has been falling steadily since the 1950s.

The rise in so called 'healthy alternatives such as almond milk has been a major contributor in dairy's decline, but according to researchers at Cranfield University, almond milk is a 'poorly described product', often containing less than 2% almonds, and is largely water, with some added vitamins, minerals, sweeteners and thickening agents. But beyond the misleading packaging and 'health' marketing, there is a much more fundamental concern about its production – water consumption.

Cranfield studies have shown that almond milk production consumes huge amounts of so called 'blue water' – water collected for human consumption or industrial and agricultural applications such as irrigation. By contrast, 'green water' is naturally occurring rainwater that is used by plants or absorbed into the soil. As part of a wider study, Prof.Tim Hess and Dr Chloe Sutcliffe from Cranfield, compared the amount of blue water needed to produce dairy milk and almond milk.

To produce one litre of almond milk requires a staggering one hundred and seven litres of blue water. In comparison, a litre of dairy milk requires just eight litres. This huge variance in the consumption of blue water is more alarming when consideration is given to the geography of the areas that produce almonds.

California in particular has a long history of growing almonds but experiences a very dry climate. Increased demand for farmed products such as almonds has led to the consumption of blue water growing at an unsustainable rate. The Cranfield study found that to grow one almond uses 6.44 litres of blue water. Therefore increasing, or maintaining, production of almonds in an area that has so little naturally occurring water could be considered both 'irresponsible and unsustainable'.

The Cranfield research is to be summarised in a ticketed, one-day course at Cranfield University on September 24. For those who can secure a place it will explain the principles of how the water and carbon footprints of our food can be assessed and why we should be conscious of both if we are to produce truly sustainable food in the future.

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