What’s the big deal with carbon anyway?
The history of carbon emissions is repeating itself (in reverse).
Our world out of balance: An Ancient Tale
At Hazel Blog, we like to think about how green agricultural practices can encourage keeping the ecological footprint of agriculture as small as possible.
But how does reducing agricultural deforestation and the resources needed for food production fit into the biggest ecological question: climate change?
You’d have to live under a pile of coal rocks to miss the rise of climate change in the public consciousness, but what’s really going on? The story of how our carbon got out of whack leads back 300 million years.
History is Repeating Itself: In Reverse
Pick up your grade school biology book and turn to the bit on the dinosaurs. You’ll probably see a big, inscrutable table that looks something like this:
Find “Carbon”, Source
Today, we’re interested in the part that says (unsurprisingly) “carboniferous period”.
Look past those images of the first tetrapods, and you’ll see A LOT of evergreen trees. The forests of the time put anything we have today to shame. During the carboniferous period, plants discovered the evolutionary equivalent of the wheel -- what we scientists call “ligninous tissue”.
Somewhat more popularly called “wood”. Wood was fantastic because it provided excellent structural support, while being distinctly untasty to herbivores of the day. (Eons later, we would use it for the same purposes actually.
Don’t have to worry about cows eating their barn) In fact, the biopolymer at the heart of wood, lignin, was so un-tasty, that paleontologist believe for millions of years nothing really knew how to eat it, even fungi.
Funny picture isn’t it? Giant pine forests, with each dead tree piling on top of the other for millennia, and no way to break them down.
Kind of the opposite of deforestation. And so, for millions of years, trees sucked in carbon dioxide and never gave it back to the atmosphere by decomposing.
All the carbon is mine! Source
With all this carbon missing, atmospheric carbon dioxide levels fell fast. By the end of the carboniferous period, average global temperature had fallen by 8 degrees celsius (14 degrees fahrenheit).
Carbon dioxide levels fell by roughly 75% over the carboniferous period, and oxygen rose to 35% of the atmosphere(compared to just 20% today).
Glacial expansion drove down sea levels, and the earth dried and cooled. In other words, those forests did a number on the climate. This intense climate change drove an extinction called “the Carboniferous Rainforest Collapse”.
Eventually bacteria, termites, and fungi learned how to eat wood at get at those pesky trees. Much of those ancient forests, however, were gone and buried by that time.
This ancient store of carbon became the coal that we dig up today. In fact, the scientific literature usually just refers to these giant, ancient forests as “coal forests”.
Termites: “Bet you think we’re not that bad now.” Source
So why does it matter today?
The world’s supply of coal is a carbon reservoir from the carboniferous period. Each time you burn coal to turn on a light, or run your dishwasher, you are using energy stored from photosynthesis 300 million years ago and sequestered from bacteria in lignin.
And you are setting free carbon dioxide to warm the earth as it did before ancient forests shuttled it away. A little detail I forgot before: prior to the carboniferous period (during the late Devonian), atmospheric carbon dioxide levels reached 15 times what they are today, and average surface temperatures are believed to have reached 30 degrees celsius.
Plant ecology plays a critical role in climate, one that we’re only just starting to understand. By conserving our forest and rainforest ecology and reducing the impact of our agriculture, we help promote ecological equilibrium.
As for coal: Let’s keep that stuff in the ground.