Snowball Earth

[Mr_Jefferson_24]

[Spitfire of ATJ]

1. Note the bottom of this familiar chart...

[cantbeserious]

2. Nice Documentary

eom

[padruig]

3. not to confuse correlation with causation

This is a interesting documentary but has a number of flaws both in logic and presentation. While it does not specifically mention (as the accompanying graph does) that the first potential snowball event could have occurred about 2bya, it does not follow that the event was associated with the shift from a reducing atmosphere to an oxidizing atmosphere.

Contrary to the suggestions of the documentary, we've always known that the gas mixture of our atmosphere was fundamental to our planetary surface temperature.

What drives me nuts about these documentaries is that they are never updated to reflect new work conducted in the field. It is now a first year undergraduate exercise to calculate the amount of solar radiation (insolation) required with a given amount of non condensing green house gases to provide the temperature range we see today on the Earth. This exercise alone gives us an energy balance model for the Earth that will tell us if an glacial age extending to the tropics is possible.

(but I loved the music - parts lifted from the Matrix films I believe)

[kenfrequed]

4. Agreed.

There are numerous problems with the snowball theory not least of which would be energy input and heat trapping needed to overcome a global albedo effect.