(Laughter)

or rather cow manure.

One cow produces 25 tons of manure every year.

And that's great because manure is a fantastic organic fertilizer.

It's chock-full of nutrients to grow our grains and vegetables.

Humans have been using animal dung as fertilizer for 10,000 years.

Without it, agriculture would have never been possible.

And that was true until about 100 years ago

when we started using petrochemical fertilizers like nitrogen.

Soon after that, manure as a fertilizer started to become much less valuable.

Today, manure looks more like this

- this is a manure pit in Switzerland -

or like this: a manure lagoon in the United States.

Now, a lot of these farms

or let me call them what they are, animal feeding factories,

don't grow the food for their animals themselves anymore.

So to them, manure is not a precious fertilizer,

instead it is just a problem that has to be managed.

This is but one of many aspects of how our industrialized agriculture today

has become so broken

that many now believe that our only ethical response may be becoming vegan.

I'm here to tell you:

please do keep eating meat and cheese.

We need animals for a sustainable agriculture,

but please stop eating

meat and cheese from animals that were fed on human food

like grains, and corn, and soybean.

Instead, only eat meat and cheese from cows that were fed on grass

like they were meant to.

I am going to tell you how that one choice is going to allow us

to tackle some of the greatest challenges we're facing today: climate change,

global soil degradation and world hunger.

In Switzerland, farmers still tried to use manure

as an organic fertilizer as best they can.

But in winter, pastures are covered with snow

so the cows are being kept indoors.

So the farmer has to store the manure in a manure pit

until he can bring it out in the springtime.

The problem is that, after a while, manure starts to rot,

and all those precious nutrients start

to turn into toxic substances like ammonia and evaporate.

Puff! And all those precious nutrients are gone.

In Germany alone, 600,000 tons of ammonia evaporate like this every year.

Standing next to one of those manure pools can feel like you're inhaling acid.

And in fact ammonia causes acid rain.

And when brought out to the field,

that manure seeps into our groundwater and rivers

and causes massive greenhouse gas emissions.

Let me take a step back and tell you how I got mixed up in all this shit.

I originally studied economics in China where lived for three years

until I got dangerously ill from the food I was eating there.

I had to take a timeout

and I was getting really paranoid about food,

so I decided to move

from a country with probably the lowest food safety standards

to... well, here, Switzerland.

I went to work on an organic farm close to Bern

and that was the first time that I got wind of this problem:

organic fields being sprayed with half rotten manure.

I always assumed that organic agriculture

is equal to sustainable agriculture.

But spraying fields with half rotten manure

didn't fit into my idea of sustainable agriculture.

And in fact, this whole manure business is not very sustainable at all.

Let's put aside the fact that I came home smelling like shit,

and taking one shower wasn't enough to get that smell off me.

That manure, when brought out to the field

is so aggressive it literally burns the plants,

and the soil takes a real beating as well.

Earthworms, that are the backbone of a healthy fertile soil,

come rushing to the surface suffocating,

only to be picked off by birds.

I thought there's got to be a better way to do this,

a better way than spraying our organic fields with half rotten manure

so I did some research and I came across an interesting master thesis

where I really thought this is something we ought to try out.

Oktoberfest is just behind us

so I'm sure you've all had a chance to eat some nice 'sauerkraut.'

But have you ever wondered

why everything in your fridge will go bad at some point,

but sauerkraut will stay good, basically forever?

(Laughter)

Well, the reason are these fantastic bacteria called lactic acid bacteria.

They take the sugar in the 'kraut'

and convert it to lactic acid making the 'sauerkraut' sour,

and thus stopping all other rotting bacteria.

In sauerkraut production, we end up with these leftover juices,

sauerkraut juice, that is chock-full of lactic acid bacteria.

Now, some people like to drink that.

It's supposed to be great for your digestion,

but let me tell you, I've tried it and I prefer a cold beer,

and so the most other people,

so this juice ends up as a waste product.

Millions of liters of it in Switzerland alone.

So I thought: why don't we take that sauerkraut juice

and put it into the manure to conserve it,

and stop all the nutrients from getting lost?

I told some friends about this idea and got them all excited about it.

We met with some top scientists in Switzerland

and put together a concept to actually implement this.

So I called the CEO of the largest sauerkraut factory in Switzerland

and told him about this idea,

and he was actually quite open to it.

Now I just need to find a farmer who would be willing to join us on this.

I ended up getting an invitation to give a pitch at the annual meeting

of the Swiss Organic Pastor Beef Association.

I was all excited and told the group of farmers

pretty much what I had just told you now,

and I asked them if anyone would be willing to join me on this.

And the room went silent.

No one put up his hand.

It was not very encouraging at all.

But after almost everyone else had left,

one courageous farmer from the Alpine region of St. Gallen,

Mr. Pirmin Koller, came to me and said:

"You know what, now that no one else is listening"

(Laughter)

"I'll give this a try with you."

So, together with the Zurich University Applied Sciences,

we put together some research parameters, and within a few weeks,

we were pouring thousands of liters of sauerkraut juice into Pirmin's manure.

And you know what? It worked!

That manure didn't smell anymore,

and all those precious nutrients didn't turn into toxic substances

like ammonia anymore and evaporated.

And Pirmin's grass turned just a little greener as well,

making his neighbor's little bit jealous

- I guess sometimes the grass really is greener on the other side of the fence -

(Laughter)

so suddenly, this wasn't just a crazy idea anymore.

A whole bunch of people got really excited about this.

The World Wildlife Foundation awarded us a grant,

and at the Falling Walls conference in Berlin,

we won the first prize out of 1,000 projects.

And that caused quite some media attention;

Swiss and German TV did segments on us

and we got a whole lot of coverage in Swiss and German newspapers as well.

And that was great because after that,

farmers from all over Switzerland, all the way to America and Australia,

contacted me,

and within three months, we had six pilot projects up and running.

But, as the results started to come in,

we realized that manure has

a much higher buffer capacity than we originally anticipated.

We needed about ten times the amount of sauerkraut juice

to conserve the manure over a six-month period.

Instead of a few thousand liters,

we now needed tens of thousands of liters.

And that's not great news because it's not Oktoberfest every day

so we don't have enough sauerkraut juice available to really scale this idea.

I realised that if I want to tackle this manure problem,

I'm going to have to understand farming from the ground up,

so I decided to become a farmer.

I'm now in my third year of a four-year vocational training program

to become an organic dynamic farmer living and working on a farm.

But not just any farm.

I work on an organic cattle farm

where they do something pretty special with their manure.

They turn their manure into pure fertile compost.

Now let me quickly explain to you how that happens

and how that is going to help save our climate and soils

and help make the world's most disadvantaged regions

food independent again.

I'm going to have to go back 3,000 years to the Indios of South America.

South and Middle America was home to some highly advanced civilizations,

with cities as large as 300,000 people.

When we Europeans were still taking a dump in our backyards

and dying of the plague,

they had already figured out an intricate sanitary system.

They would use clay pots as their toilets.

When they were done