Scientists on most sides of the climate debate agree that the effect of carbon dioxide is ameliorated as more of the gas enters the atmosphere. After all, there is no other realistic way to explain how temperatures have been lower on Earth in the past, while CO2 levels have been between 10-20 times higher. On one side of the ‘saturation’ debate, the effect is seen as minimal and unimportant. But others argue that at current atmospheric CO2 levels around 420 parts per million (ppm), most of the heat radiating from the surface has already been trapped. The latter view has the advantage of providing a more coherent explanation of the behaviour of climate across the historical and paleo record, but it leads to the inevitable conclusion that rising levels of CO2 are no threat to the planet, and in many ways are beneficial. Needless to say under ‘settled’ climate science, this hypothesis is either ignored or demonised in favour of the Net Zero-friendly version that seeks to downplay and ignore any hint of saturation.
The saturation effect can be described in simple terms by the example of loft insulation in a house. After a certain point, doubling the lagging will have little effect since most of the heat trying to escape through the roof has already been trapped. In the atmosphere, CO2 and other greenhouses gases such as water vapour and methane only radiate heat back to the surface in limited bands of the infrared spectrum. It is more complex than the loft analogy suggests, and detailed work on the subject was published two years ago by Princeton Emeritus Professor William Happer and the Canadian physicist Professor William van Wijngaarden. These two distinguished atmospheric scientists analysed around 330,000 lines of the HITRAN spectrum to observe and calculate the ability of five greenhouses gases to radiate heat. For full scientific details, their paper can be viewed here, while a recent podcast by Tom Nelson here broadcasts a detailed presentation by Dr. van Wijingaarden.
The above graph is used to show the result of their work across the spectrum. The blue line shows 394 watts per square metre (W/m2) being radiated back to space without any greenhouse gases in the atmosphere. This would lead to a world about 33°C colder than it is now. CO2 only radiates heat back in certain narrow bands and this can be seen by the dipped black line. The marginal effect of doubling current levels of CO2 is seen by the red line, and this is said to amount to trapping just a further 3 W/m2, and a rise in temperature of no more than 0.75°C.
Needless to say this work has been ignored in the important science journals and its findings have not been reported in mainstream media. Why is this? It’s not difficult to provide an answer. At a stroke, it eliminates the need for Net Zero, a political project now embedded in many countries around the world and supported by an almost unlimited transfer of wealth to many controlling and financially-interested elites. In addition, as a collectivist project seeking to change society, Net Zero is particularly appealing to many on the Left.
In his recent paper, ‘Challenging “Net Zero” With Science’, Happer made it clear that the diminishing warming value of CO2 was logarithmic, with 88% of possible warming having already occurred. “This means that from now on our emissions from burning fossil fuels will have little impact on global warming. We could emit as much CO2 as we like with little warming effect. There is no climate emergency threat at all,” he wrote.
Happer and van Wijngaarden’s work is backed up by other scientists. The German physics professor Dieter Schildknecht notes that atmospheric increases of CO2 past 300 ppm, “cannot lead to an appreciably stronger absorption of radiation, and consequently cannot affect the Earth’s climate”. He found that doubling CO2 led to 0.5°C warming as the saturation “was close to 100%”. The atomic physicist Dr. Boris Smirnov is another who has worked on the radiative abilities of greenhouse gases. He suggests that doubling CO2 would lead to a rise of only 0.4°C in global temperature, with the human contribution put at a “negligible” 0.02°C. Most of these warming figures from 0.02°C to 0.75°C are in margin of error territory, and would be impossible to discern in any natural warming phase. For their part, alarmists frequently quote rises of up to 6°C in the next 80 years.
There are many parallels in this climate science debate with Covid. Even before the first lockdown, there was enough evidence from the isolated Diamond Princess cruise ship and northern Italy to show that Covid was a respiratory disease that was only a major worry for the very old and already ill. The young were barely affected and the healthy had almost nothing to fear. But hard observations and evidence were supplanted by computer models painting wildly improbable ‘reasonable worst case’ scenarios. The Hancock WhatsApp messages show clearly what happened next. Seemingly incapable of independent inquiry, emotional politicians panicked, shut down society and were unable to find a way out of they mess they had themselves caused.
As with climate, alternative narratives were demonised, ‘garbage in, gospel out‘ models were central to misinformed Government policy, hard Left, fear-driven solutions of command-and-control were promoted, and a compliant mainstream media was enrolled to spread whatever daily message was seen as appropriate by the increasingly clueless politicians.
The saturation effect of CO2 is a plausible hypothesis that is backed up by many reasoned scientific calculations and observations. It is deserving of widespread critical debate and analysis. Human-caused global warming, and the implied suggestion that CO2 is the main climate thermostat, is a simplistic hypothesis that is unable to explain any climate changes in the past. It doesn’t have a single credible science paper that proves its validity. It fails many of the tests of scientific inquiry, and relies for its longevity on the ludicrous suggestion from many interested parties that the science is settled and beyond dispute.
Chris Morrison is the Daily Sceptic’s Environment Editor.
Stop Press: Britain has fired up back-up coal power stations for the first time ever. This is the inevitable consequence of successive Governments’ green energy policies – we’re having to rely on coal again to generate power. The Telegraph has more.
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