"Water is the hidden imbalance in U.S./China trade..."

Water is interesting stuff.
We'll have a few posts on it over the next week or so, starting off with something easy: virtual water.
From the Wilson Quarterly, Summer 2019:

The Big Leak
...The stakes for the climate and the economy are high.  

As you read this, you’re likely wearing some piece of clothing that is made in China. After all, over half of the world’s clothing is made in China.

The pervasiveness of clothing made in China in U.S. markets is certainly one of the things that comes to mind when talking about the balance of trade between the two nations.

But there is a hidden price tag on all the clothing that is made in China. It’s a considerable sum—and growing—that is skewing the trade relationship and putting its future at risk.

That hidden price tag is water. 

This hidden water in products, often referred to as virtual water, plays a significant role in the global goods trade. Water is hidden in more than just textiles; it goes into everything we use, eat, and wear. Crops must be irrigated, fuel sources must be fracked, and materials must be processed with water.

As goods are shipped and traded around the world, the water used to make or grow them is therefore also traded. When significant changes in the trade status quo occur, so does a nation’s water imports or exports—and thus its overall water supply.

If China hopes to keep its place as the world’s clothier, it must do a better job of stewarding its own water.

A Shifting Balance

One unforeseen impact of the ongoing U.S.-China trade war is a shift in the way water is spent between the two nations.

In 2017, China was the United States’ largest trading partner. Before the imposition of tariffs, China exported many water-intensive products to the United States; China is the world’s largest exporter of hidden water, and the United States is the largest importer.

Yet as trade between the two nations has stymied, the “water balance” between both the United States and China has changed.

For example, China imported zero soybeans from the United States in November 2018. Compared to the same month last year, the 4.7 million tons China imported from the United States not only represent $1.8 billion of lost value for U.S. farmers, but also a net gain of 5.08 billion cubic meters of virtual water for China.

This new reality means that the U.S. and China must adjust their water budgets—or else risk shortages. 

China’s per-capita available freshwater supply is one-quarter that of the U.S., making it especially at risk of a water shortage. China’s per-capita availability is 2,061.91 cubic meters, compared to the United States’ 8,844.32 cubic meters.

Yet despite the U.S.’s significantly larger water resources, it is China that is leaking water in the current trade regime. China exported a net 2.4 billion tons of virtual water to the United States in 2012—enough water to support 6.3 million households for a year.

Much like a carbon footprint, water consumption has a footprint. It comprises not only the water we use for drinking, laundry, and other daily uses, but also the hidden water in our products.

Clothing the world requires a lot of water: first to wash the cotton, then to manufacture it into a garment, and finally to dye and treat it. And the water required goes up when you factor in pollution: the chemical waste from this process is often dumped into rivers. 

As China continues to make more clothing, its water supply faces a double whammy: first, by sacrificing thousands of liters of freshwater for the manufacturing, and then again by polluting its own rivers, many of which are now too contaminated for human contact....

...MUCH MORE 

We've looked at virtual water a few times:

January 2013  

"PNAS Study: Population Growth Will be Constrained by the Limits of Trading Virtual Water (Food)" 

One of the few Limits to Growth that actually is a limit rather than some sort of scarcity meme.

However even this should be beatable if some smart people can do the deep dive into the wonder and magic (okay, chemistry and physics) that is H2O.
We'll be hearing about virtual water with increasing frequency, right now there are only 298,000 hits in a Google search....[now up to 459,00]

February 2014 
California Drought: Why Farmers Are 'Exporting Water' to China

March 2016
Shipping U.S. Water To Saudi Arabia
As we've noted elsewhere this is an example of what the hydrology pros call 'virtual water'.