Can Supercrops Feed 10 BILLION People?
Today's video is supported by Bill and Melinda Gates
Hey smart people, Joe here.
If you tried to sum up the last 150 years or so in one image, it might be this one:
It's a chart of exponential growth, and it shows that some things change faster over
time.
You could apply it to life expectancy.
Or compound interest.
Or any number of things.
But especially population growth.
But back in 1798 a guy named Thomas Malthus noticed that not everything grows this way.
Population growth was exponential but how much food we grow was not.
This caused people to worry…
Yet, here *we* are today.
Because that collapse didn't happen.
So how did we avoid that disaster?
That answer is important, because people are doing *this* again and
we have a new, even scarier disaster to avoid.
[OPEN]
The first time we defused the population bomb, it was mostly thanks to an agricultural level-up
known as the Green Revolution, and it's a big reason most people in the world have
enough to eat today.
At least for now.
Because even though population growth is slowing down, now we have another new scary line to
deal with: Carbon emissions and climate change.
There will be 2 billion more people on Earth by 2050 and three-fourths will be born where
climate change is going to hit hardest.
And because a lot of the food we grow feeds animals so we can eat them, this much population
growth actually means we'll need this much more crops.
This means farmers need to level up again in order to deal with droughts, floods, and
generalized chaos while still feeding more and more hungry mouths.
In the mid-20th century, Mexico, Africa, and much of South Asia faced starvation.
A book called The Population Bomb predicted famines would kill hundreds of millions of
people.
But luckily science came to the rescue before that could happen.
Researchers, led by a guy named Norman Borlaug, bred new versions of crops like rice and wheat
that resisted pests and gave larger harvests, which kept starvation at bay.
Instead of crossing a few plants together to try for a new variety, Borlaug crossed
thousands and thousands, using crop types from all over the world.
He found a wheat variety that made more kernels per plant, and crossed to make it shorter
so those big heads wouldn't fall over.
Ol' Norman & friends saved about a billion lives in the process.
Yeah, with a B. Somebody give that guy a Nobel Prize!
From the 60s to the 90s, rice and wheat yields doubled in Asia, food got cheaper, and more
people got more calories and avoided dying.
It was such a big deal, One farmer in India even named his child after a life-saving rice
strain: IR8.
How's the next Green Revolution going to work?
Some people think we can hack plant biology to get out of this pickle, using modern genetic
techniques to give plants new traits like drought, disease, and pest resistance.
Genetically modified crops containing helpful genes taken from other organisms are already
common in places like the US and Asia.
But debates over their environmental effects have kept them out of the ground in places
like Europe and Africa.
And while GM crops like pest-killing corn have lowered pesticide use by 90% in parts
of the world, some bugs like rootworms are already developing resistance to the bacterial
toxin inserted into the corn's DNA, proving just how hard it is to stay one step ahead
of nature.
Many people think the next Green Revolution won't require this extreme genetic hacking.
Instead, they believe it'll mean doing things the same way farmers have done them for thousands
of years, just doing them better with modern science.
Farmers have followed this ancient recipe for centuries: Select plants with a desired
trait, cross-pollinate, pick the best offspring, and repeat.
Very slow, and not that precise.
Wouldn't it be better if we could accurately pinpoint desirable traits, and control the
cross-pollinated offspring to speed up this same ancient recipe?
Researchers have sequenced the complete DNA genome of several crop species and done just
that.
In 2006, scientists identified a rice gene called sub1.
It comes from a variety that doesn't give much yield, but it allows rice plants to survive
underwater for weeks.
Cross-pollinate that variety with a more delicious one with a higher yield, and instead of waiting
for them to grow up to see which carry the gene, just screen baby plants' DNA.
Saves months, even years compared to the old way.
And there's no time to waste, because rising sea levels and more frequent floods are one
of the most serious impacts of climate change.
The world's poorest farmers are often on the most flood-prone land, and rice strains
like this could mean the difference between future feast or famine.
Biotechnology like this?
It's just a more high-tech version of what farmers have always done.
These new ways of doing old things are showing a lot of promise, but some scientists think
we should go the other direction and be even more aggressive with how we hack plant biology.
They're trying to play with the biology of photosynthesis itself.
Crops like corn and sugarcane do photosynthesis using 4-carbon molecules, while rice and wheat
use 3-carbon molecules.
And since C4 plants usually require less water and fertilizer, scientists are trying to re
engineer C3 plants piece by genetic piece to make more with less in a hotter, drier
world.
The first Green Revolution saved a billion lives, but it wasn't perfect.
As the same few crop varieties spread around the world, we lost a lot of local food diversity.
Today most of the world eats the same few things.
And in the process many of the world's most vulnerable farmers became dependent on expensive
and enviromentally-contaminating pesticides and synthetic fertilizers.
Local knowledge built from thousands of years of agricultural history was almost lost.
Science made their lives easier, but it also forced them to live a different way.
And in an uncertain future, that might not work.
Like most big scientific problems, the next Green Revolution won't have just one answer.
It will involve old knowledge from people who know their land better than anyone else,
using new science by people at the cutting edge of human progress, and probably a few
crazy, futuristic things we've never tried before
Because to keep up with how fast the world is changing, we have to plant as many ideas
as we can in order to keep on growing.
Stay curious
Hey guys.
This video is made possible by all of our great supporters on Patreon.
This video is also made possible by Bill and Melinda Gates.
I've been thinking a lot about milestones.
And there's one milestone from the last year I can't get out of my head.
When atmospheric carbon dioxide levels hit 415 parts per million in 2019.
I got to visit Hawaii last year when we shot a special PBS series called “Stellar”.
And I could see the Mauna Loa observatory, where they measure the planet's CO2 levels
on the mountain behind me.
I couldn't get it out of my head: We crossed a CO2 threshold our planet hasn't seen for
maybe 3 MILLION years.
It's a milestone I would like to not repeat.
Now that I'm a parent, I know if I don't try as hard as I can to help reverse this
trend now, I'll regret it later.
That's why I keep making climate videos on this channel.
It's why I took a big risk and launched a whole other channel about climate science
called Hot Mess.
Knowing that I'm working hard to help the future keeps me optimistic.
It keeps me focused on more hopeful milestones.
Climate change isn't something that's going to go away on its own.
It is 100% up to us.
And solving it and adapting to it will mean taking big risks, thinking of bold ideas,
like the ones you just heard about.
We have to swing for the fences, or we will come up short.
Big risks we take today can pave the way for future opportunities.
That's why this year Bill and Melinda Gates are sharing reflections on some of the Big
Risks they've taken in global health and education over the last two decades, and why
they'll continue making big bets in climate and gender equality in the next two.
You can hear more about what they're reflecting on, and what big ideas they've got in store,
in this year's Annual Letter.
It always gives me something new to think about, and I hope you'll check it out.
Just check the link down in the description.
Thanks, and see you next time.
