If you think winter in Chicago is cold…
After reading Mr. McKinley’s post about temperature changes, I started wondering what causes an “ice age.” I’ve heard about the ice age Earth went through however many bagillion years ago, but I’ve never really understood what makes that happen or how long it lasted. It turns out there are a few theories as to what causes ice ages. One is continental drift. As most people know, the continents today are not situated the same as they were even a year ago. The continents continue to move every year, because they are made up on techtonic plates. The shift in plates causes mountain ranges, ocean depth and size, and variety of other terrain changes. In turn, these changes effect the atmosphere and can cause temperature and climate change around the globe potentially leading to an ice age.
Another theory for development of an ice age is the amount of iron in the ocean. That seems like such an arbitrary thing, but apparently it can cause a big change. But think of it this way….iron in the ocean would stimulate plant growth, which would pull more CO2 out of the atmosphere, which would cool down Earth! This is an example of how delicate our world really is. Alongside that theory, is the main idea that the amount of CO2 in the atmosphere alters the Earth’s climate. When there is more in the ocean, the planet cools off. When there is more in the atmosphere, the planet heats up…take global warming as an example. There are many other theories to what may cause ice ages including astronomical factors, asteroid impacts, etc. Thinking about a world covered in ice sheets makes January in Chicago seem like a tropical breeze….
Picture: http://commons.wikimedia.org/wiki/Image:Inlandeis_Russels_Gletscher.JPG
Article: http://www.arctic.uoguelph.ca/cpe/environments/climate/climate_past/ice_cause.htm
