Essay on Climate Change by Reid Bryson, Ph.D. Ph.D. D.Sc. D.Engr. (1990 Laureate)

HISTORY!! (Getting back to what it sort of used to be)

Remember Otzi, the Ice Man? The fellow that was found in the mountains between Austria and Italy a few years ago? He had been shot a little over 5000 years ago, and then covered with snow, and more snow, until a few years ago the snow melted back enough for Otzi to be found. Between his burial under snow and his exhumation by nature there was more snow and ice than before, or now. Are we just getting back to what the snow climate used to be?

When the Vikings settled part of Greenland circa 900 CE, they established a settlement that lasted longer than the United States has been around. There was a considerable amount of traffic between Greenland and Europe, by the standards of the time, so some skippers were making their first trip. The directions were, at first, to sail two and a half days west from Iceland to the shore of Greenland where there stood the landmark Blasark (black shirt) Mountain. Then sail down the coast to Eriksfjord, a beautiful broad straight passage across southern Greenland. Reaching the west coast they should turn right up the coast to the navigation marker on Herjolf’s Ness. (About “Bluie West 3”in WW II.) Turning in to Tunugdliarfik Fjord Erik’s homestead Brattahlid was only 75 miles at the end of the fjord (across from Bluie West 1, for you old timers).


After 1200 CE the directions changed. Sail one and a half days west from Iceland to the edge of the ice pack. If it is clear you might see the mountain Hvitsark to the west (snow covered now?), then go all the way down around hazardous Cap Farvel and up the other coast to Herjolf’s Ness. Eriksfjord was no longer open, nor is it now. As of a decade or so ago there were two valley glaciers blocking it from the sides. Yes, I saw them. If Greenland ice diminishes some, will we be getting back to conditions like it used to be?

One of the well known climatic episodes (to well-educated climatologists) is the Little Ice Age. The hemispheric cooling started in the 1400s, really got going about 1570 (see Frobisher’s journal) and was full-blown by mid-1600s. The Pilgrims picked a lousy time to come to America. After a little amelioration, things got worse culminating in the “Year Without a Summer”. Since then the hemispheric temperature has risen, and we even have thermometers to attest to it. Gee, getting back to what it used to be sure doesn’t sound like the sky is falling and catastrophe looms. Besides, warmer weather reduces the Climatic Overhead and we get more income per unit of energy used.

Incidentally, this sequence can be modeled without even referring to anthropogenic carbon dioxide.

The Northern Hemisphere temperature history as modeled using Milankovitch variations in solar radiation modulated by volcanic aerosols, using oceans and carbon dioxide only as minor dependent variables. BP means before 1955 CE.

This figure captures very well, the “little ice age”, the Medieval Warm Period, and other known variations of late BCE and early CE times. The drivers of this model are Milankovitch calculations (average for the entire Hemisphere) and the observed volcanic record. Carbon dioxide is treated as a very minor dependent variable. It is unlikely that a general circulation model which assumes a major role of carbon dioxide can duplicate this known climatic sequence.

Reid A Bryson PhD, DSc, DEngr
(No, no references. They are in the Library and not abstracted in the internet, mostly.)
Feb.5, 2007

Reid A. Bryson Ph.D. D.Sc. D.Engr.
UNEP Global 500 Laureate
Senior Scientist, Center for Climatic Research
Emeritus Prof. of Meteorology, of Geography, and of Environmental Studies
Univ. of Wisconsin, 1225 W. Dayton St., Madison, WI 53706
Ph. 608-262-5814, FAX. 608-263-4190
http://ccr.meteor.wisc.edu/bryson/bryson.html