Climate History

Global Change was one of my favorite courses in college. One of the very first topics covered was Climate History. Climate change deniers often say that the Earth has always changed – and they are right! Actually, when climate change deniers say this, they are proving themselves wrong. They should probably clarify that they believe humans don’t cause climate change. They’re wrong about that, but that’s a story for another day.

The Earth is a living being, always changing and reforming itself.

The Earth is also old. We don’t know much about its history. We just approximate. So, here’s science’s guess at what the Earth’s climate has been like:

*BYA = Billions of Years Ago *MYA = Millions of Years Ago

1. Precambrian – 4.6-2.5 BYA
   • NO LIFE existed at this time. It was just super hot and full of radioactivity.
2. Late Precambrian – 2.5-0.5 BYA
   • Period of glaciation and cool down. There is ice at the south pole.
3. Paleozoic – 570-100 MYA
   • Time of Pangea. Plants! More oxygen.
4. Late Cretaceous – 100 MYA
   • Dinosaurs exist. No ice caps, so lots of water.
5. Late Cenozoic – 100-1.7 MYA
   • Lots of changes! 50-80% of all living things die due to a predicted wild wind storm, global fire, massive tsunami, and drought. All potentially due to an asteroid impact. Asteroid is thought to have happened due to evidence of asteroid dust and iridium. The planets starts to cool.
6. Pleistocene – 1.7-0.01 MYA
   • Series of ice ages where it cools, then warms. Ice sheets and a continent over the North Pole.
7. Holocene – 10,000 YA- today
   • Earth slowly warming. Oscillation between warm and cold, due to many many factors. Little ice ages, then industrial revolution, and Great Warming.

Earth changes whether we like it or not. I’m not really worried about Earth. It’s gonna be around a looong time. I’m worried about humans. Whether or not we cause the changes to climate, we still have the responsibility to address those changes and come up with solutions to our survival based on those changes.

In Soil We Trust,

Tiffany