Yes, it is a well known that the Earth went through extreme hot and extreme cold eras, which resulted in major extinction of life. The range of average global temps was 10 to 25 C. We are around 14 C now. The evidence comes from the fields of paleoclimatology and paleogeology.
We teach this is my energy and environment course.
________________________________
From: Phys-l <phys-l-bounces@mail.phys-l.org> on behalf of Anthony Lapinski <alapinski@pds.org>
Sent: Thursday, April 15, 2021 11:26:54 AM
To: Phys <phys-l@phys-l.org>
Subject: [Phys-L] snowball Earth
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While I was discussing the Hubble Law and expansion of the universe today
in my astronomy class, a student (senior) asked me an unrelated question
about the snowball Earth idea - that the Earth's surface was completely
frozen in the past, much more than a typical "ice age." How could this
happen? Is there any strong evidence for this? Does anyone teach this idea
or know of good research/papers (appropriate for high school kids)?
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