The strangest aspects of the human experience

How Trees Nearly Ended the World

12/12/2024

You know the age old philosophical thought experiment:

"If a tree falls in a forest and no one is around to hear it, does it make a sound?"

But let me ask you a different question: what happens when a tree falls in a forest? I am talking about the tree, it has fallen it is on the ground. What happens to that tree? Decay. 

Now I'll pose another question: what if it didn't do that? What are the possible consequences of that?

Once Upon a Time

This sounds like another thought experiment, but there was a time this was true. It was 300 million years ago, so no humans were around to hear it, but it did happen

Episode: File 0141: Werewolves of Pangea

Release Date: Dec 13 2024

Researched and presented by Cayla

300 million years ago was the carboniferous period, all those continents we have floating around now were smooshed together into two continents: Laurasia and Gondwana. Throughout this period they would slowly come together to form Pangea, but I am getting ahead of myself

Dinosaurs wouldn't arrive for another 50-80 million years or something like that, but critters had begun to crawl out of the ocean and decided they liked it on dry land, at least sometimes. These would be the first amphibians

One such order of critters were known as the temnospondyls. These were some of the first creatures that walk on dry land. They're pretty neat, squat little 4 legged dudes with lots of sharp teeth.

There were also some invertebrates that look similar to modern insects but, we'll get to them later

What you need to know is it was a hotspot for life. Plants had been doing their thing for some time, but in the last 100 million years temperatures had been slowly dropping and the amphibians and insects weren't big fans of that but what could they do, because the problem was the trees

See a Forest for the Trees

Trees were something else back then, scaled bark and fern like leaves, there's few species still alive today that look like them, and their heights were dizzying and there's a reason for that!

The first trees weren't that tall, but when they died they'd fall over and nothing would happen. Then more trees would grow, and they too would eventually die and fall over. The branches and trees that fell would pile on top of each other, eventually compressing the trees on the bottom into peat and then into coal, and the cycle would repeat

The reason for this is there was simply nothing to eat them. This hadn't really been an issue with previous plant life, lots of bugs and amphibians to snack on things. But trees they were built from sturdier stuff - literally

Trees had developed lignin, a material that was hard and sturdy and is a big part of what makes wood - wood. Having a sturdier form, trees could grow taller. And this material was so sturdy nothing could eat it. it was a pretty good time to be a tree, very little to compete with you, no humans or beavers there to cut you down. Not even the insects could harm you.

Today a tree falls and pretty quickly insects, bacteria and fungi can do away with an entire tree within a couple years depending on the environment. But 300 million years ago, none of those had evolved yet, so a tree fell, and it just stayed there eventually being compressed under the weight of more trees

This made a lot of coal. It's estimated at this time the rate of coal formation was 600 times more than the normal rate. Even wilder, is that 90% of the coal we burn today comes from this period of time. Coal beds from this period are often 35-40 ft deep.

Coal was instrumental in the evolution of human technology, if this hadn't happened, technological progression may have looked entirely different.

At its peak there were BILLIONS of trees, reaching higher and higher in competition with each other, creating the weirdest forest you ever seen, with pencil thin trees stretching up to 160 feet in the sky.

And this is story of how trees just about ended the world

Impacts of No Decay

You would've never guessed trees were so nefarious. You would think a lot of trees would be a good thing, hell today we can't get enough, they are pretty important to nearly all life on the planet, their biggest contribution is the creation of oxygen by the consumption of carbon dioxide.

Today the oxygen concentration in our atmosphere is about 20%, but back then it was around 35% which doesn't seem like a massive change, but it was, some would even call it - mega

Lots of oxygen seems great, and there are creatures that thrived in it. Remember those insects? The oxygen rich atmosphere led to the evolution of giant insects

This is the time of the griffinfly, similar to the dragonfly, except with wingspans of 28". These are the largest flying insects to have ever existed, and it was all thanks to the oxygen rich atmosphere provided by the trees

And it wasn't just big dragonflies

There was also the Pulmonoscorpius kirktonensis one of the first scorpions coming in at 28" at length

And perhaps most terrifying was the arthropleura genus, which were massive millipedes which lived in what is now North America and Europe, which were thought to be a little over 8 ft long

These critters loved to crawl through the veritable jungle gym that was the forest floor.

So good times right?

But why was increased oxygen and decreased CO2 making temperatures drop?

A general rule of the universe is that matter can't be created or destroyed, it just changes state. You can take a pot of water and boil it until the pot is empty, but the water doesn't get destroyed. It just was converted from a liquid to a gas and dispersed into the air of your kitchen as steam.

Trees intake CO2, they spit the O back out as Oxygen and the carbon stays inside. While today we generally think of CO2 as bad, greenhouse gases and all that, global warming etc. But what was happening 300 million years ago was the opposite problem

We need to CO2, well most life does anyways. CO2 hangs out in atmosphere, so when the sun shines on the planet's surface, warming it up, the gases keep some of that heat trapped. Without CO2 that heat escapes back up into space.

So with the trees absorbing all the CO2 from the atmosphere there was bound to be a problem. This is why conservation of matter is important. There is a finite amount of carbon on the planet in various states.

Let's use humans as an example. Plants absorb CO2, they spit the oxygen out which we breath, and the carbon is trapped inside, then we eat those plants, and we use that carbon for energy and to grow, some of it exits our bodies through waste and when we breathe, as we breathe in oxygen and release CO2.

But we do keep a lot of that carbon for ourselves. The average person's weight is about 18% carbon, which is a little over 20 lbs. When we die, bacteria, microorganisms and insects get to work and begin the process of decay. One of the outputs of their work is the release of methane and other gases, which releases carbon back into the atmosphere. We're really only borrowing that carbon temporarily.

So trees also borrow carbon from the atmosphere, which is also released when they decay. But 300 million years ago they didn't decay. The bacteria, microorganisms and insects that existed couldn't digest the lignin which makes up the bulk of trees.

This trapped the carbon in the trees, and with less carbon in the atmosphere more and more heat escaped back into space, ultimately leading to what is known as the Late Paleozoic Ice Age

The cooling temperatures lead to moisture in the atmosphere to fall as snow and not rain, and this snow would begin to build up on the land, as temperatures were not warm enough to melt it. Turns out when snow levels reach about 20 feet deep, it creates enough pressure for the bottom levels to begin to turn into ice. These sheets of ice continued to grow year over year, until continental glaciers formed

A continental glacier or ice sheet is described as a glacier that covers more than 19,000 sq miles, today there are only two remaining, Antarctica and Greenland, and sadly those are melting and that's bad but that's a story for another time. But here's a quick and dirty stat, if both of those melted, the worldwide sea levels would rise 230 ft, note that most of Vancouver is little more than 20 ft above sea level. Yeah that's cool.

If you have never seen a glacier in person it's hard to fathom just how big it is. It varies by glacier, but the Antarctica one is estimated to be about 7,000 ft thick of ice on average, but the general rule is a glacier's thickness is about one-half of the surface width of the glacier. It's not uncommon for glaciers to be 100s of feet thick.

When standing near a glacier, you can feel the cold radiating off it, it's an experience unlike any other and one that's only getting rarer as our planet continues to warm.


And what most people don't realize is that glaciers aren't static and stationary. They are continually moving and expanding out from what is known as the central plateau, which is the tallest point of the ice sheet. If you have been near a glacier and if you really listen, you can hear it moving

Glacier speed varies but on average 3ft per day is pretty common, but some glaciers have been tracked at 70-100 ft per day

All this to explain that because of trees, the surface of the earth was slowly being consumed by ice. It all seemed lost, until it started raining fire

Then Came the Fire

Fire existed long before humans starts rubbing sticks together, naturally most frequently caused by lightning. Typically though, lightning requires pretty dry foliage to ignite and cause a fire, like we see every year in BC, but 300 million years ago, the plant life that hadn't been swallowed by ice was damp

If you've ever tried to light a camp fire with damp firewood, you know this usually a losing battle, at least until you introduce a factor that turns up the heat. Well, you know what can really boost a fire? Oxygen, and the atmosphere was rich with it

Firestorms sound terrifying and that's because they are. Most the firestorms we have seen are manmade often tied with explosives. But they can occur naturally

A firestorm starts with a fire, with the right conditions, the fire will draw in oxygen at high speeds, often assisted by winds, the oxygen fuels the fire and the inertia pushes the fire up, exposing more surface area for more oxygen to get involved. These winds can get so intense creating what is known as a fire tornado or fire whirl

One fire storm can be devastating, the most recent big firestorm occurred in 2009, now referred to as the Black Saturday Bushfires.

On Feb 7 2009 a few bushfires existed in Australia, but winds picked up scattering fire across much of Victoria state and by the end of the day 400 individual fires raged. Fires would not be brought under control until March 14th. It's said 1,737 sq miles were burnt, over 2000 homes destroyed and 173 lives lost. This considered Australia's worst natural disaster in history

These fire happened at a time where humans had already drastically changed the landscape with millennia of logging and development. These fires were actively being fought as well

300 million years ago the amphibians weren't armed with fire hoses. Well those that still lived anyways, as I am sure as you can imagine ice ages do a number to the creatures living in those areas. But these fires were a good things, the atmosphere made them more frequent, and as it burned plants, it released carbon into the atmosphere, which would begin to start trapping heat again, which would begin to cause the ice to melt

And the more the ice melted the more plant matter would be exposed to burn. The world would find a balance again, and in that time, bacteria, microorganisms and insects would evolve be able to decompose trees

One such microbes are known as trichonympha, these tiny suckers live inside termite guts and they're kind of wild looking and those little white crystals you see everywhere? That's cellulose, like the kind that exists in trees, and they are digesting it

Nature is bonkers. It's so damn cool. But shows how a seemingly innocuous change can cause catastrophic events. Our world is intricately connected in so many ways, many we still don't understand and might not until it's too late. If trees could end life as we know it, what could what we're doing to the planet do?

Full Source List


Share