#exClimate week 2, Ancient Climate.
This week was quite interesting. Second week of the course, I'm enjoying it more than I was expecting, and even if I'm not a big fan of multiple choice questions, I'm taking all of this as a challenge with myself.
Talking about the course, this week we answered to three important questions:
How was Earth self-regulating itself in the past?
How can we have records of ancient climate changes?
Why is this important?
Obviously for this purpose we assumed Earth is a self-regulating system, with feedback mechanisms and cycles, as we said in previous week.
How was Earth self-regulating in the past?
There's a lot of study on paleoclimate recently, probably hoping that those studies can help us solve the puzzle of the challenges we have to face in the future. Since the beginning, our planet was self-regulating itself. Even if the Sun, our engine, was less brighter in those early ages, we know for sure the Earth was indeed warmer, probably because of a thicker atmosphere that help keep the warm inside. A thicker atmosphere means a high level of carbon dioxide and other greenhouse gasses. As the carbon dioxide falls down to lithosphere mixing with rain, dissolving silicate rocks that ultimately became carbonate rocks, our atmosphere went less thicker, so by the time the Sun went brighter, the system can compensate the extra heat coming from the star.
But there's a sidekick, as if the Earth gets so cold that ice can reach the tropics, then almost nothing can stop it from enveloping all the planet in a frozen land. At least for a while, because even if this happens (and it was happened for sure 600 million years ago), there's a way out, and the answer is again in the carbon dioxide cycle and volcanoes activities.
Studying this, we also learned that our precious Sun one day will be not so precious, because as it gets warmer, we escape from the habitat zone were there can be liquid water.
We also learned there is a cycle that involves how Earth is moving as a space object. It's called the Milankovitch cycle, and it involves Eccentricy, Obliquity and Precession (many ancient cultures were obsessed about those three factors, do you wonder why?).
How can we have records of ancient climate change?
There's indeed tons of instruments we can use to have access to ancient climate change evidences. Historical data for sure, but to go even further in the past we can look at ice cores and tree rings, or corals and pollutes. Sure when it comes to ancient clima it's better to have different types of evidence that could give a proper idea of what was going on so many times before we were born.
Why is this important?
Basically, this is important because looking in the past could give us answers for the future, showing us threads and dangers we might have to face. The Hockey Stink Curve, for example, show us proofs that there's something going on with the climate in our age, and that maybe carbon dioxide has a primary role with that. As a person who deeply love history I understand clearly why we are looking in the past. Human history can give us tons of bad and good examples, showing us our deepest roots and our evolution. Ancient climate changes can show us what might will happen if we're enough carefully with this delicate balance.
It's a part of the story of Earth, and we can choose to learn from it or not.
