Many people who discuss climate change believe that if atmospheric carbon dioxide levels rise so does the Earth’s temperature. This idea is simple; has the appearance of unassailable logic; and has not only infected climate science but also political organisations at the highest level. Tragically, such logic has a momentum of its own once embedded in the popular psyche. At the moment in Australia, Prime Minister Scott Morrison, Treasurer Josh Frydenberg and other key figures in Government seem beguiled by such logic.

John Tyndall was the first scientist to quantify the role of ‘greenhouse gases’ in the Earth’s atmosphere. He was an Irish physicist working at the Royal Institution of Great Britain at the behest of the great Michael Faraday. In June 1859, Prince Albert, Queen Victoria’s consort, gave the introduction to John Tyndall’s lecture on an experiment examining the various gases in the atmosphere that today we call ‘greenhouse gases’. Tyndall’s experiment showed that the most dominant gas in the atmosphere absorbing the Earth’s outgoing radiation was water vapour; the minor players were methane, ozone, carbon dioxide and nitrous oxide.

John Tyndall did not see carbon dioxide as a major greenhouse gas. It was subsequent scientists such as Svante Arrenhius (1900) and Guy Stewart Callendar (1935) who fell into the ‘carbon dioxide trap’ and completely overstated the warming role of carbon dioxide in the Earth’s climate system.

Svante Arrhenius, a Swedish physicist, thought low levels of carbon dioxide could explain ice ages and high levels the warm cycles in the Earth’s geological history. The ‘ice age problem’ had become the climate problem of late 19th century science after the Swiss scientist, Jean Louis Rodolphe Agassiz, had proved that ice had recently covered parts of Europe and North America. So, how could there be ice ages? How could the climate of the Earth change so much?

Arrhenius noted the existence of huge limestone deposits in Europe that had been deposited from the ocean in the Ordovician period over 400 million years ago. He argued that high levels of such carbonates in the ocean would necessarily mean high levels of carbon dioxide in the atmosphere due to the common link between dissolved gases in the ocean and those same gases in the adjacent atmosphere. He was right and wrong! The atmospheric levels of carbon dioxide were ten times those of today, but there was an ice age; the very opposite to his theory. Indeed, there had been another ice age 170 million years ago; it also had high carbon dioxide levels (three to four times those of today). So, in attempting to explain ice ages, Svante Arrhenius had overstated the warming role of carbon dioxide in the Earth’s climate system.

Another famous scientist to fall into the ‘carbon dioxide trap’ was Guy Stewart Callendar (1898 -1964). During the 1930s, as a hobby and working from his house in Sussex, this English steam physicist examined temperature records maintained in England, Europe and at the Smithsonian Institution in the USA. He noted that the Earth had warmed around 0.005 degrees C/year between 1900 and 1930 and that carbon dioxide levels were also rising through that period. Callendar blamed the warming on those rising carbon dioxide levels that he thought came from human industrial activity such as the burning of coal.

Like Arrhenius, Callendar was both right and wrong. Between 1900 and 1930 the Earth’s temperature had been rising while carbon dioxide levels rose around 3 parts per million/decade. However, the concurrence of these variables was not proof of their causal relationship as after the second world war, between 1940 and 1970, the Earth’s temperature fell while carbon dioxide levels rose around 6 parts per million/decade; twice the earlier rate. Furthermore, in the early 1960s, just before Callendar’s death in 1964, England endured the coldest winters since the early 1700s. So even though carbon dioxide levels were rising at twice the rate than in the early 1900s there was cooling, not warming. Indeed, if Callendar had conducted his research between 1970 and 2000 instead of between 1900 and 1930, he would have come to the same false conclusion; this was another warming period when temperature and carbon dioxide levels went up in tandem. Callendar, for all his brilliance, had overstated the warming role of rising carbon dioxide levels in the Earth’s climate system.

Today we need to be wary of another ‘carbon dioxide trap’ that is still loaded. It was set by the US Academy of Science in 1979 when it examined computer models and the computer estimates of global warming if carbon dioxide levels doubled. The Academy’s estimate was a range between 1.5oC and 4.5oC and was called the Equilibrium Climate Sensitivity Index (ECS). The Academy had examined the only computer climate models available. These had been developed by Sykuro Manabe and the climate catastrophist, James Hansen.

Forty years have passed since that Academy meeting. It is now easy to check the temperature trends predicted by any number of these computer climate models against actual changes in the Earth’s temperature. Using his models Hansen had forecasted New York to be flooded due to global warming causing a rise in sea level by 2018! The failure of Hansen’s models was damning enough, but over the last 40 years computer models have continually overpredicted global warming. The US Academy’s range of a rise of 1.5 degrees C – 4.5 degrees C, if carbon dioxide levels double, still underlies the models used in the major reports of the Intergovernmental Panel on Climate Change (IPCC –1990, 1995, 2001, 2014). An urgent downgrading of the Equilibrium Climate Sensitivity Index is overdue.

It is not unfair to say that most computer climate models are still on steroids and that the general public and media are being misled. The parameters of climate science are still set by computer programmes that exaggerate the warming role of rising CO2 levels in the Earth’s climate system. Such over-calculation adds fuel to the arguments of catastrophists and environmentalists who predict a fiery Armageddon and who want to quickly phase out fossil fuels before adequate and economically effective alternative energy solutions are developed.