Brrrrrrr! Ice Ages

 What caused the ice ages?

One thing that contributed to the ice ages was the positioning of the continents.  When the continents blocked the warm water flow from the equator to the poles - it created cold areas that were snowed on and then couldn’t warm up - forming glaciers.


Another contributor is the Milankovitch cycles - these are changes in the Earth’s orbit, rotation, and axis tilt that causes the climate to change (over the course of many years)

https://www.youtube.com/watch?v=iA788usYNWA

There were 5 major ice ages:  

  • the Huronian (2.4-2.1 billion years ago)

  • Cryogenian (850-635 million years ago)

  • Andean-Saharan (460-430 mya)

  • Karoo (360-260 mya) 

  • Quaternary (2.6 mya-present)



Uh - Quaternary said 2.6 mya to present...present - like now?

Yes - very true - but our overall temperature is up (and increasing due to climate change) and we have been pretty well out of it since 12,000 BCE.

Let’s listen to an expert (don’t worry - I found him on the web)

https://www.youtube.com/watch?v=HGPDxlz3KN0

This video promotes more of the idea of the history of the world is just one big ice age. But the better takeaway is that if you ask 10 scientists how many ice ages there were - you will get 12 answers. There are still a lot of unknown variables and these are the best guesses of current science.