This commentary originally appeared in Forbes on June 30, 2016
A decade ago, the California legislature approved legislation to increase the cost of energy as a way to reduce carbon dioxide emissions in the Golden State. During the floor debate I suggested that the Earth’s orbital precession might have something to do with the climate, given that our planet entered and emerged from numerous ice-ages before the advent of industrialization.
The response to my citation of the Milankovitch-precession and attendant solar forcing as an explanation for the ebb and flow of global glaciation was sharp, “Poppycock! Flat earth!” came the retort. I was clearly a rube for suggesting that man-caused CO2 emissions might not be the main driver of the global climate.
Now comes a new study which sheds light upon the interaction between the Earth’s precession (its wobbly 23,000 year dance around the Sun), ice buildup, carbon dioxide, dust and the rapid onset of interglacial periods. The bottom line is that CO2 has an important role to play—but not in the way we’ve been told for the past two decades
The problem with the Earth’s past periods of pre-industrial glaciation and warming is that, as the UN’s Intergovernmental Panel on Climate Change (IPCC) itself noted in its 2007 report, “The quantitative and mechanistic explanation of these CO2 variations remains one of the major unsolved questions in climate research.” In other words, we don’t know what caused large swings in atmospheric carbon dioxide in the past.
The unknown mechanism for CO2 fluctuations in the past has led to myriad climate model failures in the present as climate researchers assume carbon dioxide drives the global climate. But, as Ralph Ellis, the author of “Modulation of ice ages via precession and dust-albedo feedbacks” notes, “The primary feedback involved in modern terrestrial temperature feedbacks is said to be CO2 (plus H2O), and so it is assumed that CO2 must also be closely involved in the interglacial warming process (Hansen et al., 2012). But there is a problem with this suggestion, because high CO2 concentrations during an interglacial always result in cooling while low CO2 concentrations during a glacial maximum always result in warming…”
This is a revolutionary claim. If the global warming alarmists are correct, rising CO2 could lead to runaway planetary warming while conversely, low CO2 levels would result in runaway cooling. The geologic record of the planet shows the opposite, however, with long periods of glaciation interrupted by occasional 5,000 year periods of warming.
Ellis’ work explains these cycles by completely reinterpreting CO2 ’s role in our climate. He writes:
Ice age CO2 reductions coincide with an increase in ice sheet extent and therefore an increase in global albedo, and this should result in further cooling of the climate. But what actually happens is that when CO2 reaches a minimum and albedo reaches a maximum, the world rapidly warms into an interglacial. A similar effect can be seen at the peak of an interglacial, where high CO2 and low albedo results in cooling. This counterintuitive response of the climate system also remains unexplained, and so a hitherto unaccounted for agent must exist that is strong enough to counter and reverse the classical feedback mechanisms.
The answer to both of these conundrums lies in glacial dust, which was deposited upon the ice sheets towards the end of each glacial maximum.
The reason for all the dust just before the end of an ice-age is simple: CO2 levels fall as the planet cools, eventually causing a die off of land-based plants, especially in arid areas such as the high steppes of Mongolia. CO2 starvation causes plants to compensate but that compensation itself makes them more vulnerable to lack of water. What then happens is a rapid loss of vegetative cover that results in increasing amounts of dust in the air. That dust then coats the layers of snow in the northern hemisphere’s landmasses, significantly decreasing its albedo or reflectiveness. This causes the ice to melt at an increasing pace until the planet emerges from its ice-age—until the process repeats itself.
Ellis illustrated the historic connection between CO2, dust and temperature over the past 800,000 years in this graphic.
Ellis concludes his abstract by noting that his new thesis, “…is simple, robust, and comprehensive in its scope, and its key elements are well supported by empirical evidence.” Which, charitably, is more anyone can say about any of the current crop of climate models that are rooted in the belief that modern civilization’s use of carbon-based energy is driving our planet inexorably towards extinction.
Mr. DeVore, a Forbes contributor, was also a California Assemblyman and is a Lt. Colonel in the U.S. Army Retired Reserve.