Michael Simpson of Sheffield University did the literature review and tells it like it is in his recent paper The Scientific Case Against Net Zero: Falsifying the Greenhouse Gas Hypothesis published at Journal of Sustainable Development (2024). Excerpts in italics with my bolds and added images.
Abstract
The UK Net Zero by 2050 Policy was undemocratically adopted by the UK government in 2019. Yet the science of so-called ‘greenhouse gases’ is well known and there is no reason to reduce emissions of carbon dioxide (CO2), methane (CH4), or nitrous oxide (N2O) because absorption of radiation is logarithmic. Adding to or removing these naturally occurring gases from the atmosphere will make little difference to the temperature or the climate. Water vapor (H2O) is claimed to be a much stronger ‘greenhouse gas’ than CO2, CH4 or N2O but cannot be regulated because it occurs naturally in vast quantities.
This work explores the established science and recent developments in scientific knowledge around Net Zero with a view to making a rational recommendation for policy makers. There is little scientific evidence to support the case for Net Zero and that greenhouse gases are unlikely to contribute to a ‘climate emergency’ at current or any likely future higher concentrations. There is a case against the adoption of Net Zero given the enormous costs associated with implementing the policy, and the fact it is unlikely to achieve reductions in average near surface global air temperature, regardless of whether Net Zero is fully implemented and adopted worldwide. Therefore, Net Zero does not pass the cost-benefit test. The recommended policy is to abandon Net Zero and do nothing about so-called ‘greenhouse gases’. [Topics are shown below with excerpted contents.]
1. Introduction
The argument for Net Zero is that the concentration of CO2 in air is increasing, some small portion of which may be due to human activities and that Net Zero will address this supposed ‘problem’. The underpinning consensus hypothesis is that the human emission of so-called ‘greenhouse gases’ will increase concentrations of these gases in the atmosphere and thereby increase the global near surface atmospheric temperature by absorbance of infrared radiation leading to catastrophic changes in the weather. This leads to the idea that global temperatures should be limited to 2°C and preferably 1.5°C to avoid catastrophic climate change (Paris Climate Agreement, 2015).
A further hypothesis is that there are tipping points in the climate system which will result in positive feedback and a runaway heating of the planet’s atmosphere may occur (Schellnhuber & Turner, 2009; Washington et al., 2009; Levermann et al., 2009; Notz & Schellnhuber, 2009; Lenton et al., 2008; Dakos et al., 2009; Archer et al., 2009). Some of these tipping point assumptions are built into faulty climate models, the outputs of which are interpreted as facts or evidence by activists and politicians. However, output from computer models is not data, evidence or fact and is controversial (Jaworowski, 2007; Bastardi, 2018; Innis, 2008: p.30; Smith, 2021; Nieboer, 2021; Craig, 2021). Only empirical scientifically established facts should be considered so that cause and effect are clear.
From the point of view of physics, the atmosphere is an almost perfect example of a stable system (Coe, et al., 2021). The climate operates with negative feedback (Le Chatelier’s Principle) as do most natural systems with many degrees of freedom (Kärner, 2007; Lindzen et al., 2001 & 2022). The ocean acts as a heat sink, effectively controlling the air temperature. Recent global average surface temperatures remain relatively stable (Easterbrook, 2016; Moran, 2015; Morano, 2021; Marohasy, 2017; Ridley, 2010) or warming very slightly from other causes (Sangster, 2018) and the increase in temperature from 1880 through 2000 is statistically indistinguishable from 0°K (Frank, 2010; Statistics Norway, 2023) and is less than predicted by climate models (Fyfe, 2013). This shows the difference between the consensus view and established facts.
The results imply that the effect of man-made CO2 emissions does not appear to be sufficiently strong to cause systematic changes in the pattern of the temperature fluctuations. In other words, our analysis indicates that with the current level of knowledge, it seems impossible to determine how much of the temperature increase is due to emissions of CO2. Dagsvik et al. 2024
The IPCC has produced six major assessment reports (AR1 to 6) and several special reports which report on a great deal of good science (Noting that the IPCC does not do any science itself but merely compiles literature reviews). The Summaries for Policy Makers (SPM) are followed by most politicians. Yet the SPM do not agree in large part with the scientific assessment by the IPCC reports and appear to exaggerate the role of CO2 and other ‘greenhouse gases’ in climate change. It appears that the SPM is written by governments and activists before the scientific assessment is reached which is a questionable practice (Ball 2011, 2014 and 2016; Smith 2021).
Other organizations have produced reports of a similar nature and using a similar literature (e.g. Science and Public Policy Institute; The Heartland Institute; The Centre for the Study of CO2; CO2 Science; Global Warming Policy Foundation; Net Zero Watch; The Fraser Institute; CO2 Coalition) and arrived at completely different conclusions to the IPCC and the SPM (Idso et al., 2013a; Idso et al., 2013b; Idso et al., 2014; Idso et al., 2015a, 2015b; Happer, et al., 2022). There are also some web pages (e.g. Popular Technology) which list over a thousand mainstream journal papers casting doubt on the role of CO2 and other greenhouse gases as a source of climate change. For example, a recent report by the CO2 Coalition (2023) states clearly Net Zero regulations and actions are scientifically invalid because they:
- “Fabricate data or omit data that contradict their conclusions.
- Rely on computer models that do not work.
- Rely on findings of the Intergovernmental Panel on Climate Change (IPCC) that are government opinions, not science.
- Omit the extraordinary social benefits of CO2 and fossil fuels.
- Omit the disastrous consequences of reducing fossil fuels and CO2 emissions to Net Zero.
- Reject the science that demonstrates there is no risk of catastrophic global warming caused by fossil fuels and CO2.
Net Zero, then, violates the tenets of the scientific method that for more than 300 years has underpinned the advancement of western civilization.” (CO2 Coalition, 2023; p. 1)
With such a strong scientific conviction the entire Net Zero agenda needs investigating. This paper reviews some of the important science which supports and undermines the Net Zero agenda.
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3. Greenhouse Gas Theory
The historical development of the greenhouse effect, early discussions and controversies are presented by Mudge (2012) and Strangeways (2011). The explanation of the greenhouse effect or greenhouse gas theory of climate change is given in the IPCC Fourth Assessment Report Working Group 1, The Physical Science Basis (IPCC, 2007, p. 946):
“Greenhouse gases effectively absorb thermal infrared radiation emitted by the Earth’s surface, by the atmosphere itself due to some gases, and by clouds. Atmospheric radiation is emitted to all sides, including downward to the Earth’s surface. Thus, greenhouse gases trap heat within the surface-troposphere system. This is called the greenhouse effect.”
This is plausible but does not necessarily lead to global warming as radiation will be emitted at longer wavelengths in other areas of the electromagnetic spectrum where greenhouse gases do not absorb radiation potentially leading to an energy balance without increase in temperature.
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3.1 The Falsifications of the Greenhouse Effect
There are numerous falsifications of the greenhouse gas theory (sometimes called ‘trace gas heating theory’, see Siddons in Ball, 2011, p.19), of global warming and/or climate change (Ball, 2011; Ball, 2014; Ball, 2016; Gerlich & Tscheuschner, 2009; Hertzberg et al, 2017; Allmendinger, 2017; Blaauw, 2017; Nikolov and Zeller, 2017).
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3.1.1 The Ideal Gas Law
PV = nRT (1)
The average near-surface temperature for planetary bodies with an atmosphere calculated from the Ideal Gas Law is in excellent agreement with measured values suggesting that the greenhouse effect is very small or non-existent (Table 1).
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3.1.2 Measurement of Infrared Absorption of the Earth’s Atmosphere
It is now possible to calculate the effect of ‘greenhouse gases’ on the surface atmospheric temperature by (a) using laboratory experimental methods; (b) using the Hitran database (https://hitran.org/); (c) using satellite observations of outgoing radiation compared to Stephan-Boltzmann effective black body radiation and calculated values of temperature.
The near surface temperature and change in surface temperature can be calculated. The result is that climate sensitivity to doubling concentration of CO2 is (0.5°C) including 0.06°C from CH4 and 0.08°C from N2O which is so small as to be undetectable. Most of the temperature change has already occurred and increasing CO2, CH4, N2O concentrations will not lead to significant changes in air temperatures because absorption is logarithmic (Beer-Lambert Law of attenuation) – a law of diminishing returns.
Figure 1. Delta T vs CO2 concentration
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Ball (2014) summarizes a great deal of the geological science:
“The most fundamental assumption in the theory that human CO2 is causing global warming and climate change is that an increase in CO2 will cause an increase in temperature. The problem is that every record of any duration for any period in the history of the Earth exactly the opposite relationship occurs temperature increase precedes CO2 increase. Despite that a massive deception has developed and continues.” Ball (2014: p. 1).
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“Because of the absence of any physical evidence that CO2 causes global warming, the main argument for CO2 as the cause of warming rests largely on computer modelling.” Easterbrook (2016: p.5).
The results of the models are projected far into the future (circa 80 to 100years) where uncertainties are large, but projections can be used to demonstrate unrealistic but scary scenarios (Idso et al., 2015b). The literature that is used for the IPCC reports appears to be ‘cherry picked’ to agree with their paradigms that increasing CO2 concentrations leads to warming. They ignore the vast literature in climatology, atmospheric physics, solar physics, physics, physical chemistry, geology, biology and palaeoclimatology much of which contradicts the IPCC’s assessment in the summary for policymakers (SPM).
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3.1.4 Anthropogenic CO2 and the Residence time of Carbon Dioxide in Air
There is a suggestion (IPCC) that the residence time of CO2 in the atmosphere is different for anthropogenic CO2 and naturally occurring CO2. This breaks a fundamental scientific principle, the Principle of Equivalence. That is: if there is equivalence between two things, they have the same use, function, size, or value (Collins English Dictionary, online). Thus, CO2 is CO2 no matter where it comes from, and each molecule will behave physically and react chemically in the same way.
The figures above illustrate how exaggerated claims are made for CO2 based on the false assumption that CO2 resides in the atmosphere for long periods and can affect the climate. These results are enough to falsify the ideas of anthropogenic global warming caused by CO2 and shows how little human activity contributes to CO2 emissions and concentrations in air. The argument is clear, that if the fictitious greenhouse effect were real for CO2 the human contribution would have no measurable effect upon the climate in terms of global average surface temperature.
The residence time of CO2 in the atmosphere is between 3.0 and 4.1 years using the IPCC’s own data and not the supposed 100 years or 1000 years for anthropogenic CO2 suggested by the IPCC summaries for policy makers (Harde, 2017) which contravenes the Equivalence Principle (Berry, 2019).
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4. Conclusions
Like many other researchers it was assumed there was robust science behind the greenhouse gas theory and that Net Zero was essential to achieve, but after investigation it now appears that the greenhouse gas theory is questionable and has been successfully challenged for at least 100 years (Gerlich and Tscheuschner, 2009). Much better explanations for planetary near surface atmospheric temperatures are available based on robust, empirically derived scientific laws such as the Ideal Gas law.
