Geological Eras

Era:                     Years after 1950(?) it began:


Cenozoic                 65,000,000 years ago


Mesozoic                250,000,000


Paleozoic                540,000,000


Neoprotozoic          900,000,000


Mesoprotozoic      1,000,000,000     


Paleoprotozoic      2,500,000,000


Archaean              3,880,000,000


Hadean                 4,500,000,000


Each of these Eras may be divided into Periods. Cenozoic may be too young to have Periods.


I am pretty sure that most of these Eras belong to the Phanerozoic Eon.
 

Up-to-Date on Climate Change

Here are some notes related to climate change. I have have rechecked or updated these notes since I made them, but they are the best I have here and now:

• World temperatures rose a bit the 1400s and then dropped into the "Little Ice Age" beginning in the 1500s.
• In the 1500s sea levels were higher than they are now.
• Looking at fairly recent world temperatures, it looks as though they last peaked in about 1000 BC.
• Those interested in global temperatures tend to think in geological time.
• What's geological time?
• How do 'experts' take the temperature of the world?
• How do sea levels move up and down in relation to average temperatures?
• What were the average global temperatures in 500 BC, 1100 AD, 1400?
• The slide into our most recent drop in world temperatures lasted for about 100 years from 1500 to 1600.
• Right now, geologically speaking, it looks as though the earth has entered on of the warmest periods in the last 400,000 years.
• The last time average global temperature was as high as it is now may well have been 125,000 years ago.
• The last temperature low was about 21,000 years ago.
• What's a temperature low?
• There are a significant number of good climatologists who see a general warming trend from about 16,000 years ago.
• What is  significant number?
• How do you recognize a good climatologist?
• I got to thinking tat the earth has been on a general cooling trend for the last 350,000 years.
• Does that mean that I should forget about a warming earth?
• I'm gong to get my cooler started this month.
• Children of today may love to see strong evidence that the earth has been on a cooling trend for 4,000,000 years.
• They may be pleased that their is fair evidence that the earth has been in a cooling trend for 60,000,000 years.
• What is strong evidence?
• What is fair evidence?
• What is the evidence?
• In the larger picture, global warming looks like a small blip.
• How well a human may live through a geological blip may be worthy of our attention.
• As you educate me a bit here, I'll pass on what I learn.