The most common argument dairy industry critics like to roll out is that there are ‘plenty of alternatives to milk.’ Turns out, one of the most popular ‘plant milks’ isn’t as great as advertised.

If you were asked to name the hottest new beverage in the dairy case these days, would you guess correctly?

The answer is almond milk.

According to the WhiteWave Food Company, one of the leading marketers of “plant milks,” the firm’s first-quarter sales of almond milk were up 50 percent from the same period in 2013. In an earnings report for investors in May, CEO and founder Greg Engles told Bloomberg Businessweek that almond milk now comprises about two-thirds of all plant-based milk sales in the United States, well ahead of early arrival soy milk, with a 30 percent share, and rice and coconut milks.

Plant-based alternatives to dairy milk are indeed gaining significant market share. According to a report in TIME magazine, U.S. sales of plant-based dairy alternatives such as soy, almond, and rice milk have averaged an annual growth rate of 10.9 percent since 1999. Bloomberg Businessweek reported that in 2013 the non-dairy milk category has become a $1.4 billion market, one that’s expected to hit $1.7 billion by 2016.

And almond milk is the king of the category.

Of course, dairy milk still comprises 90 percent of all fluid milk sold in the United States. But cow’s milk consumption is dropping. To quote from a 2103 USDA report, “Dairy consumption has held steady at 1.5 cup equivalents, [although] Americans are drinking progressively less fluid milk. Since 1970, per capita fluid milk consumption has fallen from 0.96 cup-equivalents to about 0.61 cup – equivalents.”

A big piece of that lost market share has been captured by almond milk. Why? Ask most consumers, and organoleptic considerations aside, a substantial majority will typically agree that almond milk is a better “environmental choice” than cow’s milk. The reasoning goes something like this: It’s made from nuts, and nuts grow on trees, and trees are green, so voila! Almond milk must be “green.”

Plus, cows make manure, which smells terrible, so almond milk has to be a better for the environment, right?

Not so fast. Let’s dig a little deeper.

A watered down nut slurry

As a food product, almonds themselves are highly nutritious, with just one ounce (a handful) providing six grams of quality protein, three grams of fiber and 12 grams of monounsaturated and polyunsaturated fats, plus a fair amount of vitamins and minerals. However, it’s a different dietary story with almond milk.

Although most brands boast about the low calorie count per serving — an eight-ounce serving of unsweetened almond milk is only 30 to 35 calories — there’s a reason for that. The main ingredient is filtered water. That’s why an eight-ounce glass of almond milk offers only has one gram of protein and less than of one gram each of fiber, versus almost 8 grams of protein in a comparable size serving of cows milk.

By the way? Of those 30 “delicious” calories, 25 (or 83 percent) are from fat. What you’re buying for the $3.50 to $4.00 it costs for a two-quart carton is basically a container of water laced with a dose of ground almonds, plus some emulsifiers to maintain the suspension and food gums to mimic the mouthfeel of dairy milk.

But here’s the most disturbing aspect of the sudden surge in almond milk sales, which is fueled in large part by all the vegetarian advocates who ceaselessly demonize cow’s milk: It requires more than a gallon of water just to grow one single almond.

And guess who supplies 90 percent of the world — not the North American, the world — market for almonds? California, a state currently experiencing its most severe drought in half a century, according to statistics from the US Drought Monitor service at the University of Nebraska. Agriculture already consumes about four-fifths of the Golden State’s available water for irrigation, and that’s before accounting for all the processing water required to manufacture almond milk.

Even as the drought worsens across the heart of California, the growth of the state’s almond industry continues unchecked. In the last 20 years alone, according to the California Department of Food and Agriculture, total acreage planted in almond groves has soared from just over 400,000 acres to more nearly 900,000 acres — all of which require irrigation year ’round, regardless of the lack of rainfall.

A dairy operator can shrink the herd, leave some pastureland fallow and if necessary, import forage to deal with a prolonged drought.

An almond grower has zero flexibility. Those sprawling orchards need water, fertilizers and regular applications of pesticides, no matter how severe the water shortage gets.

So after consumers get past the marketing blitz touting almond milk as the greatest alternative to dairy in the history of animal agriculture, they’re left with several inescapable facts: The product costs more than milk, impacts the environment in highly negative ways and provides but a fraction of the nutritional value of cow’s milk.

No doubt, all the self-appointed vegan gurus will keep urging their followers that, “You don’t have to drink milk. There are so many wonderful alternatives.”

Alternatives? Yes.

Wonderful? Not so much.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.