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Hemp helps solve the water problem

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Cotton is thirsty. Very thirsty. For 1 kg of usable cotton fibre, you need on average almost 10,000 litres of water[1]. To give you a feeling of what this means: The cotton sold in Germany in 2010 needed almost twice as much water to be grown than all German private households and companies used in total during that entire year.

 

But at the same time cotton likes it warm and sunny. No wonder it originally evolved in tropical climate. Ironically, cotton is grown mostly in dry regions today. A main reason is that rain is bad for the parts of the plant we humans would like to use: If cotton capsules are exposed to rain and soak it up, they can go bad. So 75% of the world’s cotton today come from irrigated fields [2]. We are talking about fresh water taken from rivers, lakes, or groundwater. Most of the irrigation takes place by simply flooding the fields, and a lot of the water just evaporates unused (but hey, it’s cheap and simple!) [3]. In countries like Uzbekistan, one of the biggest cotton producers in the world, the water used by cotton comes almost exclusively from irrigation, as there is very little rainfall.

 

This is a disaster. We see soil salination, which makes agriculture harder or impossible. Groundwater levels drop, which means drinking water becomes more scarce. And we are already talking about dry regions, where water insecurity can be a problem anyway. Entire countries are already getting into conflict over water. And that’s not the end of it.

The Aral Sea before cotton irrigation started to dry it up (source of image: NASA)
The Aral Sea before cotton irrigation started to dry it up (source of image: NASA)
The Aral Sea in 2017 (source of image: NASA)
The Aral Sea in 2017 (source of image: NASA)

The most blatant example of what cotton cultivation can do is the disappearance of the Aral Sea, one of the most severe environmental disasters caused by humanity. The Aral Sea in Central Asia used to be the fourth largest inland body of water in the world, roughly the size of Ireland. When the Soviets diverted the two rivers that fed it in the 1960s into a gigantic network of channels to feed cotton, the Sea started to dry up. Today, it is almost gone. It’s not just about beaches and a fishing industry that’s disappeared. The Aral Sea was important for the regional climate, and its demise has destroyed much of the agriculture in the region. Chemicals (pesticides, fertilizers, you name it) once washed into the Sea and stored in the seabed are now blown throughout the region with the dust, causing extremely high cancer rates, respiratory diseases and all other kinds of health conditions [4]. Child mortality rates in the Aral Sea region are the highest in the world. Some call it “Silent Chernobyl”.

 

How hemp could change this? 1 kg of useful fibre needs around 2.500 litres of water, of which zero litres have to come from irrigation.[5] Do the math.

 

Notes:

[1] Cherrett, Nia/Barrett, John/Clemett, Alexandra/Chadwick, Mattes/Chadwick, M.J. (2005): Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester, Stockholm, p. 19.

[2] Cherrett, Nia/Barrett, John/Clemett, Alexandra/Chadwick, Mattes/Chadwick, M.J. (2005): Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester, Stockholm, p. 18.

[3] Cherrett, Nia/Barrett, John/Clemett, Alexandra/Chadwick, Mattes/Chadwick, M.J. (2005): Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester, Stockholm, p. 20.

[4] Small, Ian/van der Meer, J./Upshur, R.E.G. (2001): Acting on an Environmental Health Disaster. The Case of the Aral Sea, Environmental Health Perspectives 109 (6), pp. 547-549.

[5] Averink, J. (2015): Global Water Footprint of Industrial Hemp Textile, Enschede, S. 45