Engineer Joshua Pearce explains how to feed 7 billion people after a global catastrophe.
In 1841, an invasive water mold began
to infect the world’s potatoes. Starting from Mexico, the infectious
agent of blight traveled up through North America, then crossed the
Atlantic. Eventually it reached Ireland, where, as the journalist
Charles Mann described it, “four out of ten Irish ate no solid food
except potatoes, and … the rest were heavily dependent on them.”
The
Great Famine, as it came to be known, could have been avoided in any
number of ways, not least by ceasing the export of food from Ireland to
Britain. But the British government failed to take effective action. The
question of avoiding starvation becomes harder still if some
apocalyptic event causes the whole world to starve. How might a
government prepare for a worst-case scenario?
This is a question
Joshua Pearce, an associate professor of materials science and
engineering, and electrical and computer engineering at Michigan
Technological University, began to think about while working on
providing low-cost drinking water to the developing world. He found the
prospect of disaster terrifying. “This would make us no better off than
the dinosaurs, despite all of our technical progress,” he told me.
“Humanity is too smart for that.”
It sounds pretty terrifying to say, “cut down the rainforests even faster!”
Pearce partnered with David Denkenberger, a research
associate at the Global Catastrophic Risk Institute. They looked around
for detailed existing solutions and found just one: storing lots of
food. But that, the two engineers realized, would probably feed the
global population for a year or less.
So they developed a set of solutions that they believe would
provide five years of food for the Earth’s population, and published a
book about it called Feeding Everyone No Matter What. I spoke to Pearce to find out some of the very gooey ways we might survive the apocalypse.
What kinds of disasters
do you think about?
Let
me take the most likely one: the nuclear winter case. Say two countries
that both have access to nuclear weapons get very angry at each other,
and then retaliate, destroying most of the major cities in the opposite
country. The vast bulk of humanity would survive, eventually. Say maybe
we lost 5 percent of the population. Ninety-five percent of us would
still be alive. But then as those cities burned, you’d end up getting
soot in the upper atmosphere that stays there and darkens the entire
planet. And all the crops fail.
As the world went dark, you’d
have a couple of the more hearty crops survive—the trees would last a
little while. But our standard crops? Your wheat, your rice, your corn?
That’s all dead. You don’t get that harvest, and that’s what we feed the
world with. Vegetable gardens, everything’s just dead. You can’t grow
in darkness. As those crops fail, you’ll start to get hungry; you’ll
start going into your stored food supplies. The historical assumption is
that’s when we all go completely crazy. It’s bad. I’m sure you’ve seen
the movies. There’s no good outcome there. That darkness will basically
stay for around five years, until it starts to rain out of the
atmosphere and then we’ll slowly but surely [get] more and more sunlight
and start to rejuvenate agriculture again.
There’d be a little
bit of conventional agriculture that survives—like the grow houses. For
example, in Japan they have warehouses that just have racks of lettuce
growing under LED lights, and that would still work, but what fraction
of the population would that feed? I’m sure that the wealthy in
whichever culture would still pick tomatoes and lettuce, but the vast
majority of the world would not be eating those.
So what would we eat
after the sky goes dark?
There
are many things that you can eat that we don’t normally consider food,
particularly in the west. Leaves are one of them. You can eat leaves.
You just have to be careful about how you do it. Leaves are high in
fiber and we can’t digest any more than half of it, but if you chew the
leaves and spit out the fiber you can draw out nutrients from it. Or you
can make teas.
Tea in particular is a relatively easy one to
do. Pine needle tea has more than 100 percent of the vitamin C of orange
juice. One could actually make pine needle tea from the pine tree in
your backyard and get your vitamin C for the day. It’s actually a really
good superfood. And in some cultures, like [South] Korea, they even
have pop that is flavored with pine. That’s their drink.
The
other obvious one is insects. The conversion ratios between biomass and
food in insects is much better than say, in cows. Beef production is
unbelievably inefficient the way that we do it. In the west, we
definitely turn our noses up at eating insects. But there are actually
quite a few people throughout the world that eat insects today and, for
feeding everyone, it is a very obvious solution. It’s not like you have
to eat insects raw. You would never know the difference between say, a
sausage patty, a veggie sausage patty, and an insect sausage patty. It’s
all the same! It’s just the spices. Let the food scientists go crazy on
it.
Could the oceans feed us?
If
you looked at the amount of fish that we currently eat, it’s just a
tiny fraction of the human diet. You can expand that much more without
wiping out all the fisheries. If you have significant climate change,
that will result in more upwelling [seawater rise from the depth of the
ocean to the surface], which will be like fertilizing the ocean surface,
and you get more fish. Similarly we can purposely fertilize the ocean
in order to get more fish. So then we have enough fish to feed everyone.
How do you catch it all?
Then we started to look into how many
ships exist—and if we converted all of them to fishing vessels, would
that be enough in order to get enough fish harvested to meet demand? It
turned out you end up with problems such as round trip distance. You
can’t have little fishing boats go out and fish and then drive all the
way back. The solution to that is ship-to-ship transfers of fish, which
luckily, they already do now. So our fish solution is actually one of
the better ones under certain circumstances. [But] it won’t work for
everything. You still need some light.
You’ve also suggested that we eat bacteria. How would that work?
There
are two main sources of bacteria that we looked at. There is a
methane-digesting bacteria that you basically grow on natural gas. And
then we can either eat that directly or process it or say, feed it to
rats and then eat the rats. Then there’s the bacteria that we can grow
directly on wood. Or on leftover mushroom waste. And so this would be
taking down a tree, pulverizing it, turning it into a slurry, and then
letting the bacteria go at it.
When we have full agriculture production—no weird climate stuff going on—we still don’t feed everybody.
So for instance, there are bacteria that secrete
sugars they then use to feed themselves. You can pull out the sugars,
and eat those ourselves and leave the bacteria and the partially
decaying wood pulp. And we can feed that stuff to other things. So for
instance, rats digest wood to some degree, particularly after it is
partially broken down that way. This makes a fairly good solution. We
could feed something similar to chickens. And chicken is something maybe
people would maybe be happier to eat than bacteria milkshakes.
Have you tried some of these solutions yourself?
Oh
absolutely. A lot of it was just to make sure that the taste wasn’t so
bad that it would never happen. Stuff like pine needle tea is really not
that bad. Many insects are, I would even go so far as to say, tasty? If
you get by the initial sort of gag reflex. Let’s say we grow mushrooms
on logs and everybody’s eating mushrooms. Of course, that’s not
too scary. And then the waste product from that goes to feed ruminants
like cows, and then [you’ve got] beef so you know, you can still have
hamburger. It’s not that bad. We might be eating more of the cow than we
do now, but it’s not that bad.
In your book, you talk about this need for a lot of chain saws. Why would we need so many?
All
the trees would be dead, for lack of light. And so we would need to
significantly ramp up our rate of cutting trees down. Plus, temperatures
would drop. We looked at a 10-degree and a 20-degree scenario. In the
20-degree scenario, you start having things like say, all of the wood in
Canada freezes. That type of problem. Even if we want to do things like
chop the wood down and get fields of mushrooms and that kind of thing,
frozen wood is much more difficult to deal with. That’s why global
cooperation is so important. Because we’d basically be harvesting wood
supplies from the equator.
We’re probably the first to ever
calculate how many chain saws there are in the world and what their duty
cycles were and how fast we can manufacture them in order to make sure
that we had enough cutting power. Instead of say, making small handheld
devices, we could move that machinery over to making chain saws. Those
kinds of technical switches, which are really not that hard for an
industry to pull off, would need to be done on a massive global scale in
order to give ourselves the tools we need. And I know from an
environmental perspective, it sounds pretty terrifying to say, “cut down
the rainforests even faster!”
What was the most surprising thing you discovered?
It
turns out that there are several solutions to maintaining the entire
global population with things like feedstocks of primarily fossil fuels
and wood. The reason that’s so surprising is that right now, when we
have full agriculture production—no weird climate stuff going on—we still
don’t feed everybody. We still have little kids starving to death every
day and yet, I know now that we can feed them on wood pulp. It would
certainly be possible. That was very surprising.
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