Quote:
Originally Posted by scottw
Temperature changes recorded in the GISP2 ice core from the Greenland Ice Sheet (Figure 1) (Cuffy and Clow, 1997) show that the global warming experienced during the past century pales into insignificance when compared to the magnitude of profound climate reversals over the past 25,000 years. In addition, small temperature changes of up to a degree or so, similar to those observed in the 20th century record, occur persistently throughout the ancient climate record.
Figure 1. Greenland temperatures over the past 25,000 years recorded in the GISP 2 ice core. Strong, abrupt warming is shown by nearly vertical rise of temperatures, strong cooling by nearly vertical drop of temperatures (Modified from Cuffy and Clow, 1997).
Figure 2 shows comparisons of the largest magnitudes of warming/cooling events per century over the past 25,000 years. At least three warming events were 20 to 24 times the magnitude of warming over the past century and four were 6 to 9 times the magnitude of warming over the past century. The magnitude of the only modern warming which might possibly have been caused by CO2. (1978-1998) is insignificant compared to the earlier periods of warming.
Figure 2. Magnitudes of the largest warming/cooling events over the past 25,000 years. Temperatures on the vertical axis are rise or fall of temperatures in about a century. Each column represents the rise or fall of temperature shown on Figure 1. Event number 1 is about 24,000years ago and event number 15 is about 11,000 years old. The sudden warming about 15,000 years ago caused massive melting of these ice sheets at an unprecedented rate. The abrupt cooling that occurred from 12,700 to 11,500 years ago is known as the Younger Dryas cold period, which was responsible for readvance of the ice sheets and alpine glaciers. The end of the Younger Dryas cold period warmed by 9°F ( 5°C) over 30-40 years and as much as 14°F (8°C) over 40 years.
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Where is this cut and pasted from? Easterbrook's guest editorial on the Free Republic?
Let me make a comparision here. I can go find a PhD geologist (Say Dr. Marcus Ross, Liberty University) who is a fervent believer in young earth creationism. Doesn't refute evolution.
Same thing here, you find Easterbrook, with a LONG record of being a skeptic (and contributor to Glenn Beck' Show), with, in this case 15 year old data.
I was at his infamous presentation at the 2006 GSA Meeting. There is a good reason the stuff he posts in the Free Republic is not peer reviewed; it would not stand. The events he has mentioned have distinct causes independent of atmosphereic CO2. Things that, if they occured today would have the same result (Like large, sudden releases of freshwater to the ocean after draining a huge glacial lake).
but then again it's snowing in January. No climate change here