Though asteroids are small, rocky objects that orbit the Sun, they can bring tsunamis, shock waves and flattening winds that could be catastrophic. The space rocks approach towards the Earth due to the gravitational forces that affect them. It is said that one day, all life on Earth will extinct and an asteroid could be the possible reason. Shocked to hear that? Well, about 66 million years ago, a gigantic asteroid (space rock) collided with Earth, creating an explosion over 6,500 times more powerful than the nuclear bomb the US dropped on Hiroshima. The impact sent clouds of debris and sulphur into Earth's atmosphere, blocking the sun's light and warmth for about two years. Photosynthesis ground to a halt, which meant no more plant growth and due to which surviving dinosaurs starved to extinction. These days you must be hearing a lot about hovering all around the Earth. What if they hit us? Unfortunately, we do not have any weapon to destroy those asteroids, neither we have any other means to save ourselves. However, according science journalist and TIME editor Bryan Walsh, mushrooms can be used for human survival if such an apocalyptic event occur in the near future.
It is worth mentioning here that the new book of Walsh known as "End Times," examines how catastrophic events, both natural and human-made, threaten our existence. He has mentioned three types of potential catastrophes including asteroid impacts, supervolcano eruptions and nuclear war. Interestingly, all the factors are common as they could wind up blocking the sunlight needed to feed plants.
In his book, Walsh writes, "Blot out the sun, and even the best-prepared survivalist, a master of the wilderness, will starve to death along with everyone else." Walsh further noted that in a bid to survive, people would need to adopt sunlight-free agriculture - cultivating mushrooms, rats, and insects.
According to a research, the consequences of supervolcano eruptions and nuclear bombs could be similar to the aftermath of the asteroid that brought the end of dinosaurs on the Earth. According to the analysis, about 74,000 years ago, the Toba supervolcano eruption sent clouds of sulphur dioxide into the atmosphere, due to which sunlight was cut by as much as 90 per cent. That volcanic winter might have reduced the global human population to just 3,000 people, the analysis said.
"Such rapid and drastic cooling could make arming impossible, even in those regions spared by the missiles," Walsh writes. “Without sunlight, in other words, our food system would break down,” he noted.
It is worth mentioning here that the solution of cultivating mushroom in Walsh's book was adopted from David Denkenberger. Yes, you read it right. David Denkenberger was the first to suggest mushroom cultivation in a book about post-apocalyptic agriculture, called "Feeding Everyone No Matter What." Civil engineer by profession, David Denkenberger published his book in 2014.
According to the Denkenberger, when humans go extinct the world will be ruled by fungi again. "Why don't we just eat the mushrooms and not go extinct?" he told Walsh.
As per the calculations of Walsh, a 3-foot-long, 4-inch-wide log should produce 2.2 pounds of mushrooms in four years.
“While we're using the wood to grow mushrooms, we could use the dead trees' leaves, too,” Denkenberger said. "The ground-up leaves could be made into tea to provide missing nutrients like vitamin C, or fed to ruminant animals like cows or rats," Denkenberger told Walsh.
Rats, much like mushrooms, can digest cellulose, the sugar that makes up 50% of wood. So anything the mushrooms leave behind could be fed to the rats, that way, any human survivors could eat meat.
What's more, rats reproduce quickly and they probably don't need sunlight to do it, Walsh adds. It takes a rat just six weeks to reach sexual maturity, and from there only 70 days to produce seven to nine babies. In Denkenberger's calculations, all of humanity could be eating rats after just two years.
Insects could also provide protein, and many of them would survive a sun-blotting catastrophe."The same qualities that make insects so abundant and so persistent would allow many species to weather even the most extensive, climate-changing existential catastrophes," Walsh writes. "Beetles can feast on dead wood, and humans can feast on beetles." "They were both passable," he writes. "If I were starving, though, I'd manage."
It is to be noted that a car-sized asteroid slams into the Earth's atmosphere about once in a year. On the other hand, an asteroid large enough to threaten the existence of life on Earth arrives once in every few million years.