By H. Sterling Burnett, Heartland Institute
Research recently published in the journal Atmosphere concludes that carbon dioxide is only one possible forcing factor driving recent climate changes, and probably not the dominant one.
Reviewing the literature since World War II, the author, Stuart Harris, Ph.D., a professor emeritus of geography with the University of Calgary, finds multiple other explanations have been offered in various studies at various times for recent climate changes, beyond today’s current bete noire, carbon dioxide.
Atmospheric carbon dioxide is only suggested as a cause in one theory, which, despite its wide acceptance by politicians, the media, and the public, ignores the findings in other studies, including the ideas found in the Milankovitch Cycles. [Increased carbon dioxide] also does not explain the well-known NASA map of the changes between the global 1951–1978 and the 2010–2019 mean annual temperatures. The other theories by oceanographers, earth scientists, and geographers fit together to indicate that the variations in climate are the result of differential solar heating of the Earth, resulting in a series of processes redistributing the heat to produce a more uniform range of climates around the surface of the Earth. Key factors are the shape of the Earth and the Milankovitch Cycles, the distribution of land and water bodies, the differences between heating land and water, ocean currents and gateways, air masses, and hurricanes.
Harris notes that historical warming and cooling preceded changes in carbon dioxide concentrations. In addition, he points out that the recent modest increase in global average temperature began in the later part of the 19th century and early 20th century, before significant human greenhouse gas emissions, and that temperatures since then have risen and plateaued a couple of times even as carbon dioxide concentrations steadily increased.
As a result, he argues climate changes are now, and historically have been, driven by external factors like solar activity, and internal factors, such as Milankovitch cycles and how the Earth’s rotation moves fluids, and the way the Earth responds to “uneven solar heating of the surface of the Earth and the movements of the excess heat in the tropics towards the cooler polar regions, primarily by the movements of ocean currents, modified by the movements of air masses.”
Whether or not the factors Harris identifies are driving present climate change, two things we can say with some certainty about them: they impact the climate; and they are inadequately accounted for, or completely ignored, in climate model representations of the Earth’s climate and model outputs.
H. Sterling Burnett, Ph.D. is the director of The Heartland Institute’s Robinson Center on Climate and Environmental Policy and the managing editor of Environment & Climate News.