Reprinted from The Environmentor, vol. 10 no. 5, pp. 18-19

“The Soup of the Soup”

One day when Nasrudin Hodja answered a knock at his door, there stood his old friend Hassan from the next village! Even better, Hassan had brought a nice plump duck. “For you, my friend,” said Hassan. “I raised it myself!”

“Wonderful! My wife will roast it. We will have a feast. Come in, come in.” 

Nasrudin's wife was an excellent cook. Soon beautiful smells filled the house. They sat for a long time over dinner eating duck with rice and vegetables, and telling stories.

After Hassan had left, Nasrudin was happy to see that they had enough leftovers for another good meal.


The next afternoon, Nasrudin's wife made a tasty pilaf from the leftover duck meat with the leftover rice and vegetables. They were about to sit down to their dinner when another knock came at the door.

There stood a man whom Nasrudin recognized, though he could not recall the name. “Good day,” said the man. “I am the neighbor of your friend Hassan from the next village, who brought you the duck.” This man's hands were empty. 

Nasrudin realized that they had met months ago. And he knew the rules of hospitality. “A friend of Hassan's is a friend of mine. Come in and join us. We were just about to have supper.”

So they ate the tasty pilaf, but they didn't have much in common to talk about, and Hassan's neighbor left right after they finished eating.

Nasrudin's wife saw that they still had the bones of the duck, and some vegetables. “These will make a good soup for tomorrow.”


Next day, she simmered the duck bones with herbs and more vegetables. She was indeed a good cook. The soup smelled wonderful! Nasrudin was looking forward to it when –

There was a knock at the door. Nasrudin reluctantly opened it to a man who looked only vaguely familiar. “I am a friend of the friend of Hassan, who brought you the duck.” The man sniffed the air appreciatively. His hands were empty.

But Nasrudin knew the rules of hospitality. He sighed. “Come in then, and eat with us.”

This man enjoyed the duck soup so much that only a few bones and shreds of carrot remained.


The next day, another stranger came to the door empty-handed. “I am a friend of the friend of the friend of your friend Hassan, who brought you the duck!” He sniffed hopefully, but there was no smell of cooking.

Nasrudin sighed and invited him in. “Be seated,” he said, “I was about to prepare supper.”

He went into the kitchen and spooned bits of many-times-cooked carrot into two bowls. He filled the bowls with hot water from the kettle, and brought them to the table with two spoons.

“What is this?” asked the guest.

“For you – the friend of a friend of a friend of Hassan– I serve the soup of the soup of the soup of the duck. Enjoy.”

But the stranger soon left, and no more visitors came from the next town.

Nutrient Dilution

Hassan's roasted duck was full of flavor and nutrition the first night, but every time Nasrudin and his wife had to stretch the leftovers by adding less nutritious ingredients (rice, water) each portion provided less protein, minerals, and vitamins as well as less flavor.

When plants grow unusually fast, they can build a lot of tissue out of carbohydrates, cellulose, and water but they are not laying down as much protein, minerals, or vitamins as in normal growth. Animals who depend on such plants can experience what scientists call “nutrient dilution.” They may fill their bellies, as Nasrudin and his guests did on rice and broth, but they will not thrive.

Climate change skeptics point out the carbon dioxide (CO2) is essential to photosynthesis. Plants trap the sun's energy by converting CO2 and water into sugars from which they make starch, cellulose (wood), protein, and other cell biochemicals. Increased CO2 in the atmosphere (“CO2 fertilization”) will feed plants and make them grow bigger/faster, right? What's wrong with that?

The problem is that plants also require Nitrogen, Phosphorus, Potassium, and trace minerals (Calcium, Manganese, etc). When scientists enrich a plant's environment with extra CO2 but do not provide other increased minerals, they find that many crop plants (wheat, rice, peas, soybeans) and wild prairie plants can indeed grow bigger/faster – but the nutrient value of the resulting grain or hay is significantly lower than in control plants. This “Nutrient Dilution” can have bad effects on the health of animals that depend on these plants.

Scientists studying 20 years of grasshopper populations on the Konsa prairie in Kansas found that 5-year fluctuations in climate combined with long-term CO2 increases to reduce the capacity of this tall grass prairie to support a dominant herbivore. Scientists studying artificial “CO2 fertilization” of fruits and vegetables measured significant declines of 5-40% in mineral content. Some experiments also found increased susceptibility to insect attack in the fast-growing plants.

The climate change skeptics are right: CO2 indeed acts like a fertilizer for plants! But the force-fed plants are not as nutritious for animals or humans. They are “the soup of the soup of the soup” compared to plants that grow at normal rates.



“Soup of the Soup” – a Sufi tale


Facts about Nutrient Dilution: (original research report)

High CO2 Makes Crops Less Nutritious by Eli Kintisch