How will our food system change in the wake of a huge asteroid strike, according to experts!

An asteroid fell into Earth's atmosphere and crashed into the sea floor about 66 million years ago, causing an explosion more than 6,500 times more powerful than the nuclear bomb dropped by the United States on Hiroshima.

The collision sent clouds of debris and sulfur into Earth's atmosphere, blocking out the sun's light and warmth for about two years. Photosynthesis stopped, which meant plant growth stopped, and the dinosaurs became extinct.

But fossil records show that fungi thrived in the aftermath.

According to science journalist and Vox editor Brian Walsh, this makes the fungus essential for human survival if such an apocalyptic event were to occur in the future.

Walsh's 2019 book, End Times, examines how catastrophic events, whether natural or man-made, threaten our existence. In it, he suggests, three types of potential disasters — asteroid impacts, supervolcanic eruptions, and nuclear war — all have one thing in common: They can block sunlight needed to feed plants.

To survive, he says, people will need to adopt sunless agriculture.

Research indicates that the consequences of supervolcano eruptions and nuclear bombs could be similar to the repercussions of the asteroid that wiped out the dinosaurs.

About 74,000 years ago, for example, the Toba supervolcano eruption sent clouds of sulfur dioxide into the atmosphere, reducing sunlight by up to 90%. This volcanic winter may have reduced the global population to just 3,000 people, based on one analysis.

And if enough nuclear bombs (thousands of them) exploded, it could also lead to a nuclear winter that would reduce sunlight levels by more than 90%, according to a 1983 paper co-authored with Carl Sagan. Global temperatures could drop as low as 45 degrees Fahrenheit (25 degrees Celsius) in this scenario.

"Such a rapid and severe cooling could make farming impossible, even in those areas that escaped the missiles," Walsh writes.

In other words, without sunlight, our diet would crash.

Walsh's mushroom-growing solution comes from David Dinkenberger, the civil engineer who proposed it in a 2014 book about post-apocalyptic farming, Feeding Everyone No Matter What.

"Maybe when humans become extinct, fungi will rule the world again. Why don't we just eat mushrooms and not become extinct?" said Dinkenberger.

If clouds of debris or ash block out the sun and rapidly cool the climate, trillions of trees will die.

While we use wood to grow mushrooms, Walsh said, we can also use dead tree leaves.

"The ground leaves can be made into a tea to provide missing nutrients such as vitamin C, or fed to ruminants such as cows," said Dinkenberger.

Dead trees can feed other life forms, such as mice and insects.

Mice can digest cellulose, the sugar that makes up 50% of wood. So Walsh suggests that whatever the fungus leaves behind can be fed to rats. 

What's more, mice reproduce quickly and probably don't need sunlight to do so. It takes a rat just six weeks to reach sexual maturity, and from there it takes just 70 days to give birth to seven to nine mice. In Dunckenberger's calculations, all of humanity could eat rats after just two years.

Insects can also provide protein, and many of them could survive the sun's calamity.

Walsh wrote: "The same qualities that make insects so plentiful and so persistent will allow many species to survive the most widespread and climate-altering existential catastrophe. Beetles can feed on dead wood, and humans can feed on beetles."

Already considered a staple food in some parts of the world, insects are gaining traction in others. Walsh describes an insect food fair in Richmond, Virginia, where he tasted a pasta dish with ground meatballs of crickets called orzo orzo, and fried mealworm larvae.

And Walsh's book debunks another popular idea about how we feed ourselves during the end of the world: cannibalism.

He says that wouldn't help in the aftermath of a catastrophe that would put humans at risk of extinction, because others simply aren't a sustainable source of food. Walsh points to a 2017 study in which a group of undergraduates calculated how long the human race would last on cannibalism alone. They found that only one person would survive after 1,149 days (about three years).

He adds, however, that building a new agricultural system will require working together. He believes such cooperation would most likely be in a disastrous scenario.

Walsh writes: “For all our fear of what comes next, and for all our bleak stories, collapse and strife do not yet give us disaster. This is why Homo sapiens lived at the earliest opportunity with extinction - the Toba super-explosion - and this is the only way we can survive the next phase." 

Source: ScienceAlert