The Minor Greenhouse Gasses: CO2 – CH4 – N2O


This note is about the mis-representation and the resulting excessive policies implemented to address “Man-made” Climate Change that do not appreciate simple arithmetic, scale, proportionality and self-harm.

Although studiously ignored by all Climate Alarmist thinking, the Water in the atmosphere whether as Vapour or as Clouds is the main Greenhouse Gas, accounting for roughly 85% – 95% of the total warming effect.  That Greenhouse effect is essential to all life on Earth, maintaining the habitability of the planet.  The Greenhouse effect of Water in the atmosphere varies according to latitude, local climate and local humidity roughly within that range.  Mankind has no influence on the amount or distribution of water in the atmosphere.

Atmospheric CO2 at 420 parts per million is still at a low level when compared with those earlier eons when plants evolved:  plant photosynthesis is wholly dependent on the CO2 in the atmosphere.  Whatever the Climate Alarm propaganda asserts, any Man-made added CO2 can in no way be considered as pollutant, considered to be “unclean” or in any way threatening.

Carbon Dioxide in the atmosphere is the foundation of all life-on-Earth.

These calculations assume a simple 10% value for the influence of all the minor Greenhouse Gasses  CO2 – CH4 – N2O.  Because of the variability of the Global Warming effect world-wide this is an over simplification, nonetheless the scale of the calculations are correct.

The calculations here show:

  • further CO2 emissions by Mankind from burning fossil fuels cannot produce any dangerous overheating.
  • the ongoing activities of Mankind are not capable of radically affecting Climate.
  • there is no risk “a Man-made Global Warming disaster”.
  • in the past, several million years well before the existence of Mankind, when CO2 was at much higher levels, (~5000+ ppmv), the radiation physics properties of the  lowest segment of CO2, (0-400 ppmv), made a consistent ~+2.3°C contribution to Global temperatures.
  • but as the CO2 warming effect diminishes logarithmically as its concentration increases those historic high levels of atmospheric CO2 did not cause runaway overheating.
  • at the current level of ~420ppmv, the warming effect of CO2 is so saturated that the effect of any CO2 increase whether Natural or Man-made can now only be marginal, a few 1/10ths of a °C for doubling CO2 concentration:  this effect is progressively diminishing in its potential.
  • all releases of CH4 and N2O, whether Natural or Man-made have always been limited by their inherent chemistry, which ensures they dissipate rapidly in the atmosphere.  Emissions of CH4 and N2O react rapidly leaving only a minor dilute residues in the atmosphere that cannot cause any significant Global warming.

Together, the three minor Greenhouse gasses account for roughly 10% of the ~33°C Greenhouse warming effect to date.  The total effect to date amounts to ~+3.3°C.

Only CO2 has had any real relevance to the overall Greenhouse effect.  That contribution to Global temperature from the lower concentrations of CO2 has persisted at ~+2.71°C over the past 650 million years of the Phanerozoic epoch.  Screenshot 2023-03-09 at 09.35.42.png

For the last ~170 million years, the level of atmospheric CO2 has been declining progressively, reducing from ~2800 ppmv to arrive at the low level of ~180ppmv during the last ice age only 20,000 years ago.  This reduction of CO2 levels has been caused by the irrevocable sequestration of Calcium Carbonate by ocean life, as limestones, chalk, marble, etc.  

Man-kind’s CO2 emissions from industrialisation have only made a contribution to the growth of CO2 levels since the mid 1800s.  The outcome of the logarithmic diminution effect is that any further Natural or Man-made CO2 emissions can only have very limited warming effect, making any further Man-made contribution to CO2 emissions irrelevant to future Climate warming. 

Screenshot 2023-03-07 at 07.58.17

As the lowest concentrations of CO2 in the atmosphere were vastly more effective for warming, that CO2 warming contribution to Global temperature at ~+2.7°C, persisted through many previous Ice Ages over the last 600 million years.  

More recently, only 20,000 years ago at the end of the last Ice age, the level of atmospheric CO2 came very close to the terminal level of 150 ppmv, where plants can no longer survive.  At 180ppmv, CO2 was only ~20% above the level at which all life on earth could have been entirely eliminated by the failure of plant photosynthesis for lack of atmospheric CO2. 

Holocene Context for Catastrophic Man-made Global Warming

Man-kind’s CO2 emissions from industrialisation can only have contributed to the growth of CO2 levels in the last ~150 years.  The global temperature contribution from CO2 growth between 300 – 400 ppmv has only been ~+0.11°C  Now at its current 420ppmv level, the warming effect of CO2 has become virtually saturated and further CO2 emissions are only capable of having very limited warming effect.  This makes any Man-made contribution to CO2 levels irrelevant going forward.  Accordingly, all the limited actions by Western Nations to limit their CO2 emissions and in the pursuit of “Net Zero”, are therefore:

  • pointless because the developing world will continue to surpass the West’s CO2 emissions
  • unnecessary
  • irrelevant
  • costly
  • self-harming
  • environmentally destructive
  • and incidentally technically unachievable because of the non-availability of scarce mineral resources to support the proposed technologies.


If the calculations here are even close to Climate reality, they wholly negate any concern for Mankind’s future influence on the Climate and make all Western efforts to control World overheating redundant by controlling CO2 emissions very wasteful. 



The Minor Greenhouse gasses, CO2 – CH4 – N2O:  roughly 10% of the ~+33°C Greenhouse effect

Carbon Dioxide CO2:  currently ~420/1,000,000  parts per million

Global Warming Potential 1 

Estimated Greenhouse effect up to 420 parts / million  ~+2.71°C of which the Man-made temperature component can generously be estimated at ~+0.16°C.

The logarithmic diminution effect means that the lowest concentrations of CO2 are responsible for most of its warming capability.  Those levels persisted long before the existence of Mankind.  The logarithmic diminution effect decreases the influence of CO2 on temperature with increasing CO2 concentrations as is shown below, so at 420 ppmv only ~13% of the CO2 warming capability remains.  This is a 1% effect, equivalent to ~+0.33°C.Screenshot 2023-01-13 at 10.05.31.png

As far as the future effect of probable growth in CO2 concentration is concerned, there are well established and cogent technical reasons, in radiation physics, that mean that as CO2 concentration increases, so its warming capability diminishes.  From the current atmospheric concentration of CO2 at ~420 parts per million onwards, the CO2 warming effect is almost completely saturated.   Whether derived Naturally from the outgassing of warmer oceans or being Man-made, any further CO2 release into the atmosphere will have very little influence on Global temperature in future.

As the CO2 warming effect diminishes as CO2 concentrations increase, the true extent of the contribution of “Man-made Carbon Pollution” to increased Global temperature has been:

  • Much exaggerated
  • Much propagandised
  • Induced enormous fear of a Man-made catastrophe from the use of fossil fuels.

But even if CO2 levels were doubled, (ECS, Equilibrium Climate Sensitivity) the temperature outcome could well be as low as ~+0.33°C overall.

So, further Man-made CO2 emissions are no longer of any concern.

This logarithmic diminution effect is well understood and is well accepted by the Climate Science establishment.  It is referenced in the detail of its scientific IPCC reports.  But this crucial effect is neither explained nor emphasised to those involved in policy development.  This crucial fact that the influence of CO2 is currently saturated is deliberately omitted from the politically drafted any IPCC Summaries for Policy makers.

However positive this news might be, the fact that future Man-made CO2 emissions really present a non-problem is very inconvenient for the current established narrative of Catastrophic Climate Alarmism now.  Those fears are being used to undermine the Western use of fossil fuels and thus Western societies.

Professor William Happer explains this scientific process, involving the complexities of radiation physics, limiting any future warming effect from atmospheric CO2 in this presentation.

Professor William Happer shows that the according to his detailed analysis of radiation physics doubling of CO2 in future, (ECS, Equilibrium Climate Sensitivity), can only have  ~<1% effect on temperature for any doubling of CO2 concentration going forward.  The logarithmic diminution effect means that doubling CO2 concentration from ~420 ppm onwards to 840 ppm could well result in a value as low as ~+0.33°C.

Screenshot 2022-11-10 at 18.06.55.png

To paraphrase Professor William Happer:

The important point here is the red line on this chart.  It shows what would happen if the concentration of CO2 was doubled.  The gap between the black line and the red line shows the extent of the effect of doubling CO2.  So, you can see that doubling CO2 now makes virtually no difference.

On the basis of this miniscule difference, we are supposed to give up our liberties, give up the gasoline engines in our automobiles, give up all the benefits of Western Industrial society and submit to dictatorial Government controls.

The message I want you to understand is:  don’t let anyone convince you that is a good bargain:  it is in fact a terrible bargain.”


A diagram of Logarithmic Diminution of CO2 warming

Screenshot 2023-03-09 at 10.51.41.png

This diagram shows the following:

  • CO2 overall capable of contributing ~8.2% of the 33°C  ~2.7°C:  data EPA.
  • The absolute lower limit of CO2 concentration for the viability of photosynthesis and thus all life on Earth is ~150ppmv
  • The significant temperature effect of the lower concentrations of CO2: up to the plant viability level of 150 ppmv is already achieving ~70% of the temperature contribution of CO2.
  • The low level finally reached during the last ice age 180ppmv, only ~20,000 years ago: this was extremely close to the fatal level for planetary extinction of 150ppmv.
  • The lowest level reached during the last ice age 180ppmv already accounted for ~75% of CO2 warming effectiveness, equivalent to ~+2.0°C.
  • The CO2 temperature contribution from 180ppmv up to 420ppmv since the last ice age ~+0.4°C to reach the current 2020 temperatures.
  • The limited temperature effect of doubling CO2 up to 840ppmv from now on ~+0.33°C or ECS Equilibrium Climate Sensitivity because the temperature effect of CO2 is now so close to saturation.
  • The rapidly diminishing temperature effects of increasing CO2 concentration.
  • The damaging effect of lowering levels of CO2 on plant life and thus all life on Earth, dependent on photosynthesis.
  • The improving productivity of plant life with increasing concentrations of CO2.



Methane CH4: ~1,900 / 1,000,000,000 parts per billion

Global Warming Potential ~20 x CO2

Total Global estimated Greenhouse effect ~0.33°C:  estimated Man-made temperature component ~0.062°C

Methane is a more powerful Greenhouse gas than CO2.  However, Methane reacts rapidly with Oxygen in the atmosphere:  it oxidises back to CO2 and Water almost immediately.  So, Methane dissipates quickly on its release.  ~80% of Methane is continually released from natural sources and dissipates.  The common example is as Marsh Gas where its oxidation is even visible when released in higher concentrations over swampy ground as “will-o-the-wisp”.  The remaining ~20% is from agribusiness and industrial leakages.   As Methane oxidises rapidly in the atmosphere, the residual level of Methane is self-limiting and so remains low.

As a result of its the low residual concentration of Methane has a small warming effect.  Like CO2 its effect also diminishes logarithmically with any increasing concentration.

Click to access Methane-and-Climate.pdf

Nitrous Oxide N2O:  53 / 1,000,000,000:  parts per billion

Global Warming Potential ~230 x CO2

Total Global estimated Greenhouse effect ~0.198°C with an estimated Man-made temperature component ~0.010°C

If Nitrous Oxide did not react on its release into the atmosphere and were able to maintain high concentrations, it would indeed be a very powerful greenhouse gas but at ~53 parts per billion it is virtually absent from the atmosphere.  The bulk, ~95% of atmospheric N2O release is produced naturally, (largely from nitrogen cycle with the natural decomposition of organic matter and to a lesser extent from continuous atmospheric lightning strikes.  N2O reacts immediately and dissipates on its release into the atmosphere.  A balance of ~5% arises from Man-made emissions industrial processes, fuel burning and diesel transport.

This paper from 1999 concluded that because of the immediate reaction of N2O in the atmosphere it was not a pollutant threat to health even in a crowded city like London.

“TRANSPORT and HEALTH in LONDON a Report for the DEPARTMENT of HEALTH   1999”

“Nitrogen dioxide N2O at high concentrations has a variety of environmental and health impacts. It can be a respiratory irritant, may exacerbate asthma and possibly increase susceptibility to infections. In the presence of sunlight, it reacts with hydrocarbons to produce photochemical pollutants such as ozone.

Nitrogen oxides have a lifetime of approximately 1 day with respect to its conversion to nitric acid.  This nitric acid is in turn removed from the atmosphere by direct deposition to the ground, or transfer to aqueous droplets (e.g. cloud or rainwater), thereby contributing to acid deposition.”

Transport and Health in London

The exaggerated Green concerns over the virtually harmless and rapidly dissipating N2O emissions from diesel vehicles lead to the Volkswagen emissions scandal.  The whole VW emissions question was a confection resulting from VW’s attempt to by-pass ill-considered regulations that were put in place to address what is in fact a self-limited, non-problem of N2O emissions from diesel vehicles.  In spite of N2O being a very marginal climate pollutant, transportation induced N2O emissions in the West are now largely avoided by the use of AdBlue exhaust technology.

This is not to say the particulate matter mainly from older diesels are not a real pollution problem.

As Nitrous Oxide breaks down rapidly in the atmosphere, its residual level is self-limiting and remains low.  At its very low residual concentration Man-made N2O contributes virtually nothing to Global warming, an immeasurable 1/100°C  ~0.01°C, from a total N2O effect of ~0.19°C.

Nitrous Oxide at really high concentrations, were they able to exist, could correctly be classed as a pollutant.

Nitrous Oxide and Climate


Nitrous Oxide and Climate

C. A. de Lange, J. D. Ferguson, W. Happer, and W. A. van Wijngaarden

November 30, 2022


Higher concentrations of atmospheric nitrous oxide (N2O) are expected to slightly warm Earth’s surface because of increases in radiative forcing. Radiative forcing is the difference in the net upward thermal radiation flux from the Earth through a transparent atmosphere and radiation through an otherwise identical atmosphere with greenhouse gases. Radiative forcing, normally measured in W m−2, depends on latitude, longitude and altitude, but it is often quoted for the tropopause, about 11 km of altitude for temperate latitudes, or for the top of the atmosphere at around 90 km. For current concentrations of greenhouse gases, the radiative forcing per added N2O molecule is about 230 times larger than the forcing per added carbon dioxide (CO2) molecule. This is due to the heavy saturation of the absorption band of the relatively abundant greenhouse gas, CO2, compared to the much smaller saturation of the absorption bands of the trace greenhouse gas N2O. But the rate of increase of CO2 molecules, about 2.5 ppm/year (ppm = part per million by mole), is about 3000 times larger than the rate of increase of N2O molecules, which has held steady at around 0.00085 ppm/year since the year 1985. So, the contribution of nitrous oxide to the annual increase in forcing is 230/3000 or about 1/13 that of CO2. If the main greenhouse gases, CO2, CH4 and N2O have contributed about 0.1 C/decade of the warming observed over the past few decades, this would correspond to about 0.00064 K per year or 0.064 K per century of warming from N2O.

Proposals to place harsh restrictions on nitrous oxide emissions because of warming fears are not justified by these facts. Restrictions would cause serious harm; for example, by jeopardising world food supplies.



The Man-made contributions to the Greenhouse Effect

CO2 is increasing mainly form the outgassing of slightly warmer Oceans over recent millennia.  CO2 is largely absorbed by natural photosynthetic processes, the increased levels of CO2 have already achieved very significant, beneficial greening of the biosphere.  CO2 emissions are retained in the atmosphere to a certain extent and their absolute levels are increasing.

Screenshot 2023-02-07 at 11.44.15

Screenshot 2023-01-01 at 10.46.06.png

In these simple calculations it is assumed that all the extra CO2 emissions since the Little Ice Age, 280ppm – 420ppm, ie +~140ppm are Man-made.  This is an overestimate.  But when accounting for the logarithmic diminution effects at progressively higher CO2 levels this amounts to ~6% of the whole ~2.71°C attributable to CO2 resulting in a Man-made component of ~+0.16 °C.  A more likely but still conservative Man-made contribution to the CO2 Greenhouse effect could be about half the growth in CO2 concentration since the Little Ice age:  percentage data EPA.

The values shown above fully account for the fact that ancillary Greenhouse gasses CH4 – N2O are much more effective Global Warming agents.  But their very low residual levels as they react rapidly in the atmosphere almost dissipate almost immediately.

At its lower concentrations, (0 – 280 ppmv), long before Man-kind existed, CO2 achieved more than ~80% of its warming potential and has always made a real contribution to Global temperature, up to ~2.5°C.

The Man-made element of other Greenhouse gasses, CH4 – N2O are irrelevant in the their contributions to Man-made Global warming.  As their warming influence is trivial, any action to control or limit these minor Greenhouse gasses is pointless and potentially very damaging.  Injudicious and unnecessary action to control those emissions particularly any limitation of N2O, is capable of doing vast damage to the Western economies and particularly to Western agribusiness.  Banning the use of Nitrogen fertilisers can lead to a 50% reduction in crop yields.

Some Western governments are taking actions to control the use of Nitrate fertilisers, which according to these findings could only make a difference to the Man-made Global warming contribution of about 1/100°C, 0.01°C at most, even if those limiting actions were applied Globally.  The two Western Nations currently acting on Nitrogen Dioxide emissions by limiting Nitrate fertiliser use are involved in the productive agribusinesses of Canada and the Netherlands.

Action to limit artificial Nitrogen fertilisers in Sri Lanka has immediately destroyed the verdant and viable economy of  22 million people.  In less than a year Green policies have lead to socioeconomic breakdown and famine.

In other words, the Man-made contribution at current levels of Minor Greenhouse gasses is marginal and can only remain so going forward.  Any concern over human emissions of N20 with a global effect of ~1/100°C is entirely unwarranted but its control and attempts at its imitation have the potential to be hugely destructive of the food supply of Western and Global civilisations.


Some Conclusions

These proportional calculations show that the Man-made contribution to Global Warming / Climate Change from CO2 and Methane emissions can only be marginal going forward.  They are absolutely miniscule from extra Nitrous Oxide.

But Climate alarmists and Climate activist administrations have indulged in a massive over exaggeration of the adverse Man-made impact of using Fossil fuels and the effect of other nominal “pollutants” on the Greenhouse effect to support and promote their obsessive, quasi-religious beliefs in an impending and sudden Man-made Climate Catastrophe.

In Geopolitical terms, the message of absolute and immediate catastrophe promoted by Green thinking can only be regarded as the continuation of the Cold War intent on damaging the economies of Western societies.  The security danger to the West posed by Green thinking was fully recognised by NATO Secretary General Anders Fogh Rasmussen in 2014, citing for example the substantial covert Russian financial support for Greenpeace and many other Western environmental NGO’s.

But this fifth column “Green thinking” has successfully infiltrated Western Governments and all levels of Western society so that the actions to react to the now minor forward Climate effects of emitted Greenhouse gasses are now undermining the economic viability of Western Nations.

This effective Green campaign against Western civilisations has managed to eliminate even the possibility of privately funded exploration for indigenous natural Gas produced from Fracking throughout Europe.  These resources could well have been brought on stream over the past decade.  Had Fracking for Gas not been obstructed by Russian originated malicious propaganda supporting Green dogma, Europe and particularly Germany would now be largely independent of Russian gas imports and Russia would not now be in a position to intimidate European Nations in the Winter 2022 – 2023 in the course of it pursuit of its war in the Ukraine.

So, the all actions to combat Catastrophic Man-made Global overheating and from attempting to control Man-made Climate Change arise from an attractive preoccupation to demonstrate Western “Virtue” in “nominally saving the planet”.  China, India and all developing Nations, ~80% of the world population and already ~65% of the world CO2 emissions, rightly have no concerns for their own escalating CO2 output:  they will continue to  grow their emissions of CO2 as they continually advance their development and they will happily watch the economic self-harm inflicted on Western economies.

Screenshot 2022-08-05 at 07.34.26

All efforts to limit Western releases of CO2 and other minor Greenhouse gasses are thus entirely futile.

As the underdeveloped Nations continue the advance of their well-being Global Man-made, CO2 emissions will roughly double if they were to reach China’s present level of CO2 emissions.

China And India Will Watch The West Destroy Itself – OpEd

The ill-considered Western “Virtue” of appearing to do the “right thing for the “Climate” overpowers any rational and quantified consideration of the consequences.  Any questioning of that “dogmatic consensus of Climate Catastrophe” results in immediate denigration of all opposing views, rather than in the concerned questioning of the matter, which should be the normal response under any ordinary scientific thinking.  The denigration of the opposing Climate Change views had a close parallel in the reaction to opposing views to Covid-19 lockdown policies:  likewise those policies have now been shown to be hugely damaging to Western civilisation and economies.

In spite of the enormous cost and damage to Western enterprise in attempting to achieve “Net Zero”, the Climate alarmist lobby has managed to avoid any “Red team – Blue team ” questioning due diligence questioning their overriding quasi-religious view of an impending man-made Climate Catastrophe.

The damage is already evident in the reliability and costs of Western Power generation.  The effects are now coming to the Western agribusiness, for example in the Netherlands and Canada.  In those Nations damaging policies are being pursued to affect N2O emissions, which might influence Global warming but the extent of the warming potential Globally is to a maximum extent an absolutely undetectable ~1/100°C.

Accordingly Western Green policies have:

  • ignored and obscured the minor scale of the warming effect of any Man-made emissions in contributing to the Greenhouse effect and the potential for Global temperature increase going forward.
  • ignored the miniscule effects that any local Western CO2 emissions mitigation measures might ever achieve to avert the asserted Catastrophic Climate Change.
  • immediately put the whole of the European economy at risk in the Winter of 2022 – 2023.  This damage and the extra costs of Energy are likely to persist for several years to come.
  • rendered European economies susceptible to energy blackmail by Russia in pursuing its aggression in Ukraine.
  • withheld investment, (via ESG, Environmental Social Governance), and vastly damaged previously established and reliable Fossil Fuelled and Nuclear power generation systems:  these are the only technologies capable of doing the heavy-lifting for Electrical Power generation and providing the reliable support essential to advanced Western societies.
  • called into question the productivity of Western agribusiness to influence a potential Global temperature effect as small as ~0.01°C.  Influencing a 1/100°C change in Global Temperature would be both undetectable and immeasurable, well within any margins of measurement error.


These simple calculations show that all concerns about the Minor Greenhouse Gasses CO2 – CH4 – N20 and all policies and expenditures on Climate mitigation going forward are worthless and irrelevant.  All Climate mitigation efforts could well be terminated without any damage to the Biosphere and Mankind. 

Indeed the termination of the efforts to control climate could be of great benefit to Mankind, especially if those vast funds are applied to other much less costly and the many truly beneficial objectives.

So there is:

  • no need to have any concern over the future Global emissions of CO2.
  • no need to limit the development potential of the Developing World:  their CO2 emissions using their indigenous fossil fuels are bound to grow as they advance their well-being.  Developing World actions will eventually result in a doubling of the current level of Global Man-made CO2 emissions.
  • no need to compensate the under-developed World for providing them with access to the technologies that will advance their well-being.
  • no need to try to artificially limit the use of Fossil fuels by Western Nations with the various lower productivity technologies being proposed and mandated by Government to pursue the pointless goal of “Net Zero”, including:
    • inefficient Weather-Dependent “Renewable” energy:  the recorded combined European “Renewables” productivity for Wind and Solar power is ~20%.

Would anyone sane buy a car costing up to 10 times the normal price to buy and run, that can only work one day in five, when you never know which day that might be ?  And then insist that its technology is the only way to power the whole economy. 

    • the elimination the internal combustion engine.
    • the imposition of Electric Vehicles, impractical even for personal transport, let alone for all commercial transport and any construction or agricultural  requirements.
    • imposition of limits on domestic use of fossil fuels for heating and their replacement with inefficient Heat Pumps.
    • attempts to “decarbonise” manufacturing  industries.
    • development of an inefficient “Hydrogen economy”.
    • elimination of Nitrogen-based fertilisers, because they are derived from Natural Gas in the Haber-Bosch process and can release Nitrous Oxide globally responsible for ~ 0.01°C of the Greenhouse effect.
    • etc.  etc.
  • all Green technical suggestions disregard Engineering considerations of productivity and promote increased demands on electrical power generation and at the same time mandate a reduction in productivity of power generation and exploitation.

These are systems that support current civilisation, they have been honed to be effective and very efficient over the last 100 years.


  • All Green technical proposals lack engineering coherence and so  fly in the face of the axiom of:

“If it ain’t broke don’t fix it”

And for what? to try to fix what is possibly a minor or even non-existent problem 100 years hence but the efforts to fix it will cause untold immediate economic damage to Western societies.