Good morning, John. It is the last day of Pizzamas and to celebrate,  I want to show you one of my favorite maps.

I would, in fact, love to pay someone to attempt to make, like, a scientifically informed yet beautiful version of this map that provides as much detail as possible in helping folks understand where the land that they are on now was when all of the land was smushed together into one giant supercontinent.

In the middle  of this supercontinent, you can see a place where there was once this, like, warm, swampy, nameless area that would one day become the United Kingdom.

Now, at that same time 300 million years ago, and on that land, something remarkable was happening. In the space of around 50 million years, land plants went from a maximum height of around 30 centimeters to a maximum height of around 30 meters.

This was a very fast change and resulted in some very intense problems, including, we think, a mass extinction event.

So what happened was plants that could get higher than other plants got access to more sunlight, and if you didn't get high, you were in the shade and you died.

So, there was a very strong selective pressure toward plants getting taller, and that resulted in some biochemical innovations like tougher plant tissues and also big, deep roots.

Importantly for us today, and also everybody who was around back then, there was a pretty big gap between when plants figured out how to create those strong hard tissues and when other organisms figured out how to break them down. Meaning plants were sucking CO2 out of the atmosphere to build those tissues, but there was a limited number of paths for breaking those tissues down and re-releasing the carbon dioxide.

It's basically the opposite of the problem that we have today. Carbon dioxide concentrations in the atmosphere plummeted. And that, combined with tree roots breaking up rocks and releasing a ton of new minerals into the oceans, is probably what kicked off the late Devonian mass extinction event.

Now, do I blame trees for creating that mass extinction event? No, they didn't know what they were doing,  but it does seem like they did do it.

But. I said before that this event was also important for us today, and it was. Because all that new vegetation wasn’t decomposing, a lot of it ended up getting buried and over time, smushed together through geological processes where it later would form coal. And in this warm, swampy part of the world at the center of Pangea, that was happening a lot 300 million years ago.

Fast forward a bit. Around 2000 years ago, people on that same land started digging up that coal and burning it to heat their homes and cook their food. But the burning of coal in that land would remain a pretty insignificant thing until around 150 years ago. At that point, this place, because of its ancient history and the luck of tectonic movement keeping much of that coal close to the surface of the land, and also because of the particular history and culture of its people, it began a process of digging up and burning coal that created a graph that very much looked like a roller coaster that would always, always go up.

The first ever coal-fired power plant was built in London in 1882. At its peak, coal produced 76% of the UK's power. And that peak was around 40 years ago. So, like, not ancient history. But now, I would like to show you  a video taken this week of the UK's power mix. And there it was. The last coal-fired power plant in the UK has shut down.The end to a 300-million-year-old story.

Now, certainly the rise of natural gas as a cleaner, cheaper source of fuel was a big part of that peak beginning to plummet in the 90s. But also the 2008 Climate Change Act was a big part of it. And also, in 2015, people of the United Kingdom said that they were going to  phase out coal over the next ten years, and then they did that.

But also a big part of that was the complete geographic luck that is the UK’s relatively fantastic position with regard to wind resources.

So there's a lot going on here, but this is a big deal. And in the circles I travel in, it was celebrated enthusiastically, though I get the impression that most people didn't really notice.

Per-capita CO2 emissions in the UK are now lower than they were in 1854. But of course also, this happened the same week as a flood that has  absolutely ravaged a part of my country that I love very dearly and where I have friends right now trying to figure out how to put  their lives back together.

And we know that that flood happened because our newer, warmer atmosphere carries more water. And that happened because we have been digging up old trees and burning them. And that coal was there because 300 million years ago, there was an evolutionary arms race for access to the Sun that resulted in a fundamentally changed Earth.

I kind of can't believe I get to be a witness to the story of Earth,   but even weirder than that, and also more intimidating, I get to be a participant.

The trees caused their mass extinction. And in a way, that is less worrying than people doing it, because people theoretically know better. But also, the trees were worse. Like, not morally, of course; practically, though, because the trees couldn't do anything to stop themselves. But we can.

I don't know that we will, at least not as fast as we need to. But if given a choice between that one and this one, I'll take this one because at least now we have some agency. At least now there's a chance.

John, thank you for a wonderful Pizzamas. As always, 100% of profit from Pizzamas gets donated to help Partners in Health build healthcare systems in places where they are most needed.

Everybody, today through the weekend is the last time to get Pizzamas stuff. We sold out of a bunch of things, but we also undersold on some things. So because we need to get that inventory out of the warehouse, we got some amazing deals right now.

Let's take a look at the spreadsheet I just got of the Pizzamas sales. There's a 50% discount on the lunchbox, 45 on the blanket, 35 on the pimple patches, 50% on the tattoos and the clog charms.  I guess we legally can't say Croc. And then 60% on the BRAT shirts, and 60% on a bunch of stuff that we have left over from previous years. Also, if you get that steeply discounted  blanket, you also get a free Pizza John print. I'll put a link to all this in the description.

All for the love of the bit and all to support Partners in Health. John, I'll see you tomorrow.