Early Earth Reflection

The Habitable Planet Section One video was very informative about how the Earth transformed drastically from an uninhabitable planet to one that can easily sustain life. It explained how our planet was not always the place we know it to be now and how complex life forms are a relatively recent addition to the overall timeline of the Earth. The two main reasons why the Earth became habitable for complex life forms were due to the stabilization of the planet’s temperature with the greenhouse effect and the rise of oxygen levels.

While I was familiar with some of the topics mentioned in the video, I did not know that complex organisms were a relatively new addition to the planet - only starting to appear 550 million years ago. I also was not aware of the fact that the Earth was once completely covered in ice and had similar conditions to Mars. I’m still a little unclear as to when major events such as ice ages occurred in relativity to the timeline of the planet. While the video did a very nice job explaining why ice ages occur, it did not really tell us when they occurred.

I knew a little bit about the greenhouse effect prior to watching this video, but I did not know much about the entire carbon cycle behind it. The scientists in the video quite obviously knew what they were talking about, but brushed over the carbon cycle rather quickly. I would have liked the video to have gone a little more in-depth with a topic as complex and interesting as the carbon cycle. It is essentially the reason we exist today and I feel like the video could have spent more time explaining it.

I did learn a lot of new information from the video though. One of the things that really caught my attention was exactly how important geology is to better understanding our planet. Geologists can use rocks to explain almost the entire history of the Earth. They use rocks to determine things such as ice ages and oxygen level increases. They also use the rocks to find fossils and piece together various species’ evolutionary history. I was incredibly fascinated by all of this and cannot wait to learn more!

Image Citations:
Snowball Earth - http://images.spaceref.com/news/oosnowball.earth.2.jpg
Carbon Cycle - http://www.esrl.noaa.gov/gmd/outreach/carbon_toolkit/images/carbon_cycle.jpg