Good Morning John, I want to tell you about one of the  coolest things I’ve ever found out about in my life.

It really threw me for a loop–  and I want to throw you for the same loop. So, join me on the journey.

When studying life on our planet, it is sometimes useful to think about,  like, how much the living matter of the planet weighs. On its own. This is enough of this coat.  On it’s own the idea of living matter is pretty freaking weird, right?  Living matter.  But that’s what we are.

And matter has mass. Like, I have about 90,000 grams of living matter. Or do I?

Like not really. Most of it’s water. Like, life couldn’t exist without it,  but it isn’t really a part of the living system.

It’s kind of just like an ocean that I’m carrying around  with a sac with me everywhere I go so that I can do the chemistry that is life. What the scientific establishment  has decided to do is just to count the carbon? Which makes sense.

I think that’s a good   way to do it. Of course,  it’s not perfectly precise but it’s precise enough. We call this biomass.

For example if you look at the biomass  of all mammals around a third of it is human beings. If that seems weird to you, it’s gonna be way weirder than that. That’s like the least weird thing in the video.

Another third is COWS! Just cows. And you might be thinking that leaves another third  for wild animals.

I’m sorry, no.  A further 30% is the rest of the agricultural animals. And 4%. 4% of mammal biomas  is wild mammals. All of the whales and elephants, and skunks and armadillos and shrews.

Now is that the weirdest thing in the video?  No, it’s not. I used to think when  I heard this stat, that this meant that there  used to be 100% wild mammals, and now, like 96% of them  have been replaced by agricultural animals and humans. But that’s not what happened.

Around 100,000 years ago, humans had a very tentative foothold  on the planet. Pretty insignificant species in terms of biomass. And at that point wild mammal biomass was at it’s peak,  but it had been roughly the same for a very long time.

It wasn’t increasing, it wasn't decreasing,  it was quite stable. Between 100,000 years ago and 10,000 years ago,  human biomass changed some, but was still pretty insignificant  to 10,000 years. But wild mammal biomass dropped by like 25%.

A very big, very fast drop. We call this the quaternary megafauna extinction. It was an extinction event of almost entirely very large mammals.

Lots of debate about this,  definitely a contributor to it was humans. It’s very tightly coincided with the arrival with humans in North  and South America, and separately, in Australia. But what happens next is the very weird part.

Between 10,000 years ago and 100 years ago agriculture happens. Like, in a big way.  Wild mammal biomass falls by a further third. But the total mammal biomass increases beyond what it ever was.  Purely because of humans and livestock.  And now in the year 2022 humans by themselves represent  three times more biomass than all mammals combined before humans.

We are heavy. And in the last 100,000 years there has been an 85% decrease in the  wild mammal biomass and an 800% increase in the total mammal biomass. Throughout this video I’ve been trying not to have  any particular judgment about whether the world should be the way that it is,  just that it’s fascinating that it is the way that it is.

But entering into our conclusion here. Aaah– it’s bad.  Like, it’s bad to have an 85% decrease in wild mammal biomass. But it’s all very complex.

Like the earth is absolutely 100%  its historical maximum of complicated brains. I don’t know if y’all caught this, but a few days ago some days  ago some baby was born that was the 8 billionth person on the planet.  I hope they at least got a certificate. So I don’t really know what to say  about this, except that obviously we need to be doing all of this quite  thoughtfully because this is a very big and fast change.

And I think that you can actually make the case that we are actually doing  it more thoughtfully now then we were 100 years ago. It’s also really great to be able to get coffee and socks delivered  to your door once a month and to know  that there are people working hard to try and do that as thoughtfully as possible. Coffee plantations can, for example, can often lead to deforestation,  but be done in partnership with a forest.

The small farmers of the Awesome Coffee Club work hard  to decrease deforestation and to practice regenerative agriculture. The sock club is closing Monday. There will not be another Vlogbrothers  video between now and then, so if you wanna sign up,  you’ve gotta do it now.

The coffee club will remain  open perpetually! John, I’ll see you on Tuesday