Lee C. Gerhard, PhD, CPG has been studying and writing about climate change science for more than 30 years.
Gehard’s background is geology, and he is retired from the Colorado School of Mines as the Getty Professor of Geological Engineering and as Director and State Geologist of the Kansas Geological Survey.
Historical Myopia, A Modern Disease
Missing from the current climate hysteria is any indication that alarmists who forecast cultural crisis from a gradually warming earth have any knowledge or understanding of climate history. They are caught in their own hubris, thinking that only their lifetime experience captures the total reality of earth’s climate dynamics. Implicit in their myopia are assumptions that carbon dioxide (CO2) is the single most important driver of climate change, present climate change is beyond historical norms, that humans can materially alter an Earth dynamic system and that warming will inevitably continue.
No formal test of the carbon dioxide-as-climate-driver theory has been permitted, but that is of no consequence, nor are the scores of technical papers theorizing the atmospheric physical details, both pro and con, of understanding the causes of climate change. The one critical question that remains to be resolved is: Is there proof that our current climate and concurrent recent changes are in any way extraordinary when compared to pre-industrial changes?
Fortunately, that question can be answered with empirical data without resorting to computer models. Oxygen isotope data and CO2 data from Arctic and Antarctic ice cores provide empirical historical temperature and carbon dioxide concentration over several hundred thousand years. Reliable empirical and interpreted information about temperature changes over human history has been collected and made accessible by Lamb (1995) and by numerous other less comprehensive studies (see Table 1 in Lamb, 1995, for detailed descriptions of data types and significance).
Ice core data not only instruct us with examples of past rapid large amplitude temperature swings but also document that rising temperature causes rising CO2, the direct opposite of the prevailing theory (Fischer et al, 1999) (the graphic former Senator Gore used to demonstrate CO2 driving temperature actually proved the reverse). What caused such temperature swings? Bond et al (2001) documented glacial thawing periods in the North Atlantic Ocean that were accompanied by beryllium isotope excursions that prove coincident increased solar intensity. Whether increased solar energy resulted from solar changes, orbital changes or both is not clear (Zahn, 2002). There is no indication in the data that carbon dioxide played any role in driving the melting episodes.
Recurring cycles of temperature change are evident in the geologic and human historic record (Hoyt and Schatten, 1997; Davis and Bohling, 2001). Three of these cycles are of particular importance. The ten to eleven-year solar cycle is well-recognized and is of minor importance to climate change calculations. The millennial (~1000 year) and the Gleissberg (60-80 year) cycles are very important to understanding climate change. In reverse chronologic order, there is the putative Modern maximum, then the Medieval, Roman, and Minoan cycles. The Medieval is the best studied of these, owing to data availability and proximity to modern history. During the temperature maximum two Viking agricultural colonies flourished on Greenland. Viking expeditions explored parts of eastern North America and there is anecdotal evidence that Chinese vessels transited the Northwest Passage. The cycles do not change temperatures rapidly, although it appears that warming happens faster than later cooling. By 1400 the Greenland communities were cut off by ice and all perished. In the larger context, several lines of evidence and data show that 4000 years ago Earth was much warmer than today. That is apparently when agriculture was firmly established and communities were organized.
From 4000 years ago to present, the Earth has been cooling episodically, the cooling interrupted only by the millennial warm peaks, each of which is cooler than its predecessor. Earth is not in a warming crisis. If there is to be a human crisis, it is because of cooling. So why the hyperbole about warming?
The Gleissberg Cycle is important because it encompasses a normal human life span, giving greater importance to individual experiences rather than the longer climate change history. The current cycle began in North America in the mid-1930’s, the U. S. high was 1934. It bottomed out around 1970, and reached its apex again about 1999. For the average American, the last 50 years has been warming and there is no memory of the previous parts of the cycle. Global warming is what people have experienced, although they have no understanding of the larger context (It must be noted that government temperature data from weather stations has been greatly corrupted by “corrections” to make older data colder, thus showing more warming). “Ever” cannot be casually defined as just the last 50 years. Alarmists who state current temperatures as “hottest ever” are either uninformed or devious.
Archibald, (2022) illustrates the current solar cycle intensity compared to previous cycles, indicating the likelihood of cooling to take place over the next decades. This statement is speculative. What we have learned from climate history is that human society prospers during warm periods and suffers during cold episodes. Increased CO2 and warm temperatures have greatly increased food production, while prospective cooling might harm that advance.
Takeaways from knowing climate history:
1) Knowledge of climate history obviates the need to consider either carbon dioxide or detailed atmospheric physics to know whether there is no “climate warming crisis” today or in the future.
2) The Earth has been cooling for more than 4000 years and will continue to cool for the foreseeable future, although the cooling is episodic rather than linear.
3) There is no global warming crisis. Modern temperature changes are well within normal natural change parameters.
4) Increased concentration of carbon dioxide has little effect on climate compared to natural effects.
5) Earth’s atmosphere is historically low in carbon dioxide to nourish plant growth; satellite images document greening of arid regions over the past 30 years.
6) Climate change is driven by solar and orbital variations, modified by large scale ocean current changes.
7) Earth appears to have entered the downturn part of a Gleissberg Cycle. History demonstrates human society suffers in cold times. Perhaps technology will prevent widespread harm.
Archibald, David, 2022, Solar Update: The Wentworth Report. Feb. 2, 2022.
Berner, R., 1994, 3Geocarb IIA Revised model of atmospheric CO2 over Phanerozoic time: American Journal of Science, v.291, p. 56-91.
Bond, G., B. Kromer, J. Beer, R. Muscheler, M. N. Evans, W. Showers, S. Hoffmann, R. Lotti-Bond, I. Hajdas, G. Bonani, 2001, Persistent solar influence on north Atlantic climate during the Holocene: Science, v. 294, p. 2130–2136.
Davis, J. C., and G. Bohling, 2001, The search for patterns in ice- core temperature curves, in L. C. Gerhard, W. E. Harrison, and B. M. Hanson, eds., Geological perspectives of global climate change: AAPG Studies in Geology 47, p. 213–230.
Fischer, H., M. Wahlen, J. Smith, D. Mastoianni, and B. Deck, 1999, Ice core records of atmospheric CO2 around the last three glacial terminations: Science, v. 283, p. 1712–1714.
Hoyt, D. V., and K. H. Schatten, 1997, The role of the sun in climate change: New York, Oxford University Press, 279 p.
Lamb, H. H., 1995, Climate, history, and the modern world, 2d ed.: New York, Routledge, 433 p.
Zahn, R., 2002, Milankovitch and climate: The orbital code of climate change: Joint Oceanographic Institutions for Deep Earth Sampling Journal, v. 28, no. 1, p. 17–22.
“I never fully accepted or denied the anthropogenic global warming concept until the furore started after NASA’s James Hansen’s wild claims in the late 1980s. I went to the [scientific] literature to study the basis of the claim, starting with first principles. My studies then led me to believe that the claims were false.” — Dr Lee Gerhard: [email protected]