“The Greenland Ice cores show many instances of dizzying changes. The temperature can go up or down 10 to 15 degrees Centigrade in a few years, or in 40 years. There have been periods where Greenland heated 1 degree per year for 5 years – which is 100 times faster than our current warming. It might plateau there for 30 years or so, and then go into another 5 year period of 1 degree warming per year.
“The Earth’s climate is NOT STABLE. There have been 24 warming events found in the ice cores in the last 115,000 years. Studying the warming, about 14,000 years ago, as discussed by scientist Geoffrey C. Bohling, they found 10-15 degrees C happening in 1 to 2 years.
. . .
Work by David Archer at the University of Chicago showed the last time Earth had 400 ppm CO2, was about 2.5-3 million years ago. Sea level was 20 meters higher – 65 feet higher!! Earth was less than 2 degrees C warmer than now.
[39:30] Scientists Foster and Rohling looked at relative sea level. There was a fairly stable plateau of about 14 meters higher than today; 45 feet higher, which lasted from about 300 ppm to about 600 ppm; over 600-700 ppm you start to melt all of Antarctica, and sea level eventually goes up 70-80 meters.
We are at 400 ppm, and Jim White bets we will hit 600 ppm at the end of the century.”