One “baked-in” aspect of the Climate Leadership and Community Protection Act (Climate Act) is its obsession that using natural gas, aka methane, is such a danger to climate change that its use must be curtailed now and eliminated as soon as possible. I say “baked-in” because the language of the Climate Act was written to deliberately and uniquely emphasize its alleged impacts on global warming. A paper by van Wijngaarden & Happer makes a persuasive case that New York’s obsession to reduce methane is wrong. Unfortunately, the paper is very technical and my attempt to describe it for a wider audience has resulted in a dense post that probably won’t be much help to many.
Here are the key points to keep in mind as you read this post. The van Wijngaarden & Happer paper describes an analysis that used many observations of the greenhouse effect to develop a general relationship that can be used to predict the effect of increasing concentrations of greenhouse gases. New York Climate Act guidance is based on claims that methane has a more potent impact on the greenhouse effect than carbon dioxide but the van Wijngaarden & Happer derived relationship shows that methane cannot cause significant changes to the greenhouse effect itself. The analysis shows this is because of the saturation effect, the amount and type of radiation emitted from the surface, the numerical realities of infrared absorption, and the physical properties of the real atmosphere related to the greenhouse effect.
Everyone wants to do right by the environment to the extent that they can afford to and not be unduly burdened by the effects of environmental policies. I submitted comments on the Climate Act implementation plan and have written extensively on New York’s net-zero transition because I believe the ambitions for a zero-emissions economy embodied in the Climate Act outstrip available renewable technology such that this supposed cure will be worse than the disease. Although the implementation process claims to adhere to the “science” I have found many examples where the claims are not supportable. The opinions expressed in this post do not reflect the position of any of my previous employers or any other company I have been associated with, these comments are mine alone.
The goal of the Climate Act is to reduce emissions from 1990 levels to net-zero by 2050. Previously I explained that the language of the law mandates a unique accounting system for greenhouse gas (GHG) emissions. The result is that New York’s GHG baseline inventory for 1990 is nearly double previous inventories that were consistent with GHG emission accounting methodologies used by the Intergovernmental Panel on Climate Change (IPCC) and the United States Environmental Protection Agency. There are three primary reasons for the near doubling of the emissions inventory. The Climate Act inventory adds a requirement to include not only direct emissions but also emissions associated with upstream emissions. The second change modified the potential effect of methane on global warming by changing the time horizons and, finally, the emission factors used are inconsistent with other jurisdictions.
I believe that the primary source of this methane obsession in the Climate Act is Dr. Robert Howarth. As one of the authors of the Climate Act, he was in a position to incorporate the anti-natural gas language. He is also a member of the Climate Action Council that is responsible for developing an implementation outline for the transition to net-zero. In that role he disparages the continued use of natural gas at every opportunity. Howarth is the David R. Atkinson Professor of Ecology and Environmental Biology at Cornell University. His training was in oceanography, much of his research still focuses on coastal marine ecosystems, and he also works on freshwater systems (both rivers and lakes). Despite his lack of meteorological and air quality background and education he has followed the money to become a shill for the special interest foundations opposed to natural gas use and has conned the state into obsessing about the global warming impact of methane in the Climate Act.
Infrared Forcing by Greenhouse Gases
In order to explain why New York’s methane obsession is misplaced it is unfortunately necessary to go into the technical details of the paper by van Wijngaarden & Happer “Infrared Forcing by Greenhouse Gases”. Fortunately, there are several descriptions of the paper that are more understandable. Dr. C. A. Lange prepared a summary of the paper that he thought a lay person could understand. In my opinion, it is still a challenge primarily because there are few illustrations in his summary. Dr Thomas P Sheahen prepared a video presentation on the paper and I will incorporate his illustrations into my simplified description why methane is irrelevant. I followed his explanation approach and recommend the video itself. Finally, an amicus curiae brief from a just convened court case provides another description of the aspects covered in the paper. Hopefully this article will distill the information from those references to provide an explanation that more people can understand.
At its core, the global warming concern is that changes in the earth’s radiation budget will increase the energy in the atmosphere that will lead to warming at the earth’s surface. Sheahen included the following figure that shows the earth’s energy budget as percentages of the solar energy coming to earth. Incoming solar energy or sunlight is in the form of shortwave radiation. A total of 30% of the radiation is reflected back out to space from the atmosphere, clouds and the earth’s surface as shown in the yellow arrows pointing up. The atmosphere absorbs 16% of the solar energy and clouds absorb another 3%. The remaining 51% is absorbed by land and oceans. The absorbed energy at the earth’s surface is radiated back into the atmosphere as longwave radiation.
As an aside: One problem deciphering these technical reports is that the same phenomenon can have different names. In this case longwave radiation is also called infrared radiation per the title of the paper in question.
Gases in the atmosphere have different capabilities for absorbing this longwave radiation. Greenhouse gases absorb that energy and can radiate it back to the earth’s surface, to other greenhouse gases or out into space. Increasing greenhouse gases in the atmosphere increases the amount radiated back to the earth’s surface and increases atmospheric temperatures. Eventually, as shown by the red upward facing arrows, 70% of the energy is radiated back into space mostly from the clouds and atmosphere (64%) and 6% is radiated directly from the earth’s surface.
The Climate Act regulates the following greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and carbon tetrafluoride, and sulfur hexafluoride. The fact that their effect on longwave radiation decreases as their concentrations increase is an aspect of these gases that has been ignored by the Climate Act and the Environmental Protection Agency (EPA). This is called the saturation effect.
On October 14, 2022 an opening brief was filed at the DC Circuit Court of Appeals, Concerned Household Electricity Consumers Council (CHECC) v. EPA, that challenges EPA’s 2009 Finding that CO2 and other greenhouse gases constitute a “danger” to human health and welfare. A week later an amicus curiae brief was filed in support of CHECC by the CO2 Coalition together with Professors William Happer of Princeton and Richard Lindzen of MIT. On page 29 of the brief the saturation effect is described:
Drs. Happer and Lindzen have special expertise in radiation transfer, the prime mover of the greenhouse effect in Earth’s atmosphere. It is important to understand the radiation physics of what the effect is of adding CO2 at current atmospheric concentrations. CO2 becomes a less effective greenhouse gas at higher concentrations because of what in physics is called “saturation,” shown in the chart below.
This version of the saturation curve projects that the carbon dioxide CO2 warming effect is increased between 0.6o C and 0.8o C when the atmospheric concentration is increased from 100 ppm to 150 ppm. The total expected effect of CO2 is the sum of all the bars. It does not mean that there will be no effect of added greenhouse gases but that the effect is reduced. The takeaway message from this graph is that if today’s CO2 concentration of around 400 ppm were doubled to 800 ppm the expected increase is the sum of all the bars to the right of the red arrow that I estimate to be about 1 o C of additional warming. That is on the order of one third of what the IPCC claims. The brief sums it up: “This means that, from now on, our emissions from burning fossil fuels will have a modest and a declining impact on greenhouse-induced warming”.
In order to make projections of future GHG impacts the IPCC uses global climate models (GCM) that simulate all the physical processes in the atmosphere that affect climate. The radiative processes described here are only one, and frankly a small one at that, of the processes that affect the climate. Individually we have a good understanding of the laws of physics but solving them as necessary to make climate projections is extremely difficult if not impossible. Although the IPCC Third Assessment Report admitted this “The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future exact climate states is not possible”, this point has been largely ignored since. In order to get any kind of an answer requires the modeling analysis to make many simplifying assumptions. Our concern here is just one component: atmospheric radiative physics, that is to say the interaction of all the components of the atmosphere with the shortwave and longwave radiation that ultimately drives the greenhouse effect. It turns out that the IPCC GCMs have “not been able to replicate the increasing number of very diverse observations that are gradually becoming available” for this component. The comparison of results from this component of the GCMs relative to observations shows poor correspondence and indicates their treatment of the saturation effect is likely incorrect.
Amount and Type of Radiation Affecting the Greenhouse Effect
Observations of the amount and type of radiation emitted from the surface were the primary driver of the analysis by van Wijngaarden & Happer. Their focus on the radiation emissions combined state-of-the-art physics with the best observations available of the radiative processes in the atmosphere to determine just how much of the longwave radiation will be reduced and how much the greenhouse effect will be increased. In particular they used the HITRAN database which is a compilation of measurements used to predict and simulate the transmission and emission of energy in the atmosphere. This is a database that includes thousands of observations of the shortwave and longwave radiation processes that affect the intensity of the greenhouse effect.
Recall that white sunlight (the shortwave radiation described before) is made up of a spectrum or bands of different wavelengths seen as different colors. This is the physics behind rainbows. Rainbows are formed as a result of the dispersion of white light split into seven colors after passing through a raindrop. Each color represents a different band of wavelengths.
The following diagram from the Amicus Brief shows the longwave spectrum of energy coming from the earth’s surface. The smooth blue curve represents the expected radiation from a black body aka Plank’s Law. The brief explains that “The area under the blue curve is “the heat the Earth would radiate to space if our atmosphere had no greenhouse gases or clouds, and if the surface temperature were 60° F”. The black curve represents measurements of the actual radiation coming from the earth so the area under the jagged black curve is the heat radiation that is actually observed. The area between the blue and black curves represents the greenhouse effect. Note that the greenhouse gases, water vapor (H2O), nitrous oxide (N2O), carbon dioxide (CO2), ozone (O3), and methane (CH4), affect different areas of the curve.
The black curve represents today’s conditions at 60° F and the figure shows the effect of zero and doubled CO2. The green curve shows radiation to space if there was no CO2. Clearly CO2 has the largest effect on today’s greenhouse effect. The red curve is the radiation to space if CO2 concentrations were to be doubled from 400 ppm to 800 ppm, with no changes in other greenhouse gases. One can barely make out the difference, about 1.1% of the radiation before doubling. For this change in the greenhouse effect, we expect that the surface temperature would increase by a trivial amount, about 1° C (1.8° F) or less.
The van Wijngaarden & Happer paper analyzed thousands of radiation measurements of the black curve and developed a theoretical relationship to predict how changes in ambient conditions, including concentrations, would affect the spectrum of wavelengths. Their derived relationship represents conditions in the actual atmosphere not the theoretical and simplified atmosphere used by the IPCC and EPA. Importantly, all five GHGs were considered at the same time using their observed concentrations. When the derived relationship is compared to observations for different locations on the earth the results are remarkably similar.
Sheahen argues that this represents the correct use of the Scientific Method and the fundamental truth that observations always trump model output. Because there is good agreement between projections estimated from their derived relationship and actual measurements, we have a “computational method that is trustworthy”. As a result, “we can now conduct numerical experiments with CO2 doubled, halved, etc”. The IPCC theoretical results do not meet this fundamental test and should not be trusted.
For example, we can use the derived relationship to consider the effect of adding different increments of CO2 as shown in the following diagram that focuses on one portion of the curve. Remember that the greenhouse effect is represented by the difference between black smooth curve and the jagged curves below it. The diagram shows that there is a very small greenhouse effect due to increased CO2. This is primarily because of the saturation effect discussed previously.
The biggest reason that methane is irrelevant is because of the numerical realities of infrared absorption. The following diagram varies methane (CH4) instead of CO2. The wavelengths affected by methane are to the right of the peak of the curve. Remember that the greenhouse effect is represented by the area between the blue curve and the other curves. Because the section of the curve where methane affects longwave radiation is smaller than the section at the peak of the curve where CO2 has its primary effect, methane simply cannot ever cause as much of a change in the greenhouse effect. Also note the methane greenhouse effect at current concentration levels is only the small difference between the green line and the black line because of the saturation effect. If methane is doubled (the red curve) there is no visible change in the greenhouse effect at this resolution.
The next diagram expands the resolution enough to see the doubled concentration effect (the red line) but it is clear that there is no significant effect for methane and that current levels of methane are not a significant factor in the overall greenhouse effect.
Nitrous oxide (N2O) has also been vilified because of its high global warming potential so I have included the analogous diagrams. In this case there is potential for more of a significant impact because the longwave frequencies where N2O reduces transmission include an area near the peak of the curve. The results due to the saturation effect are the same and there is there is no visible effect for a doubling of current concentrations. There is another reason N2O is inconsequential that will be discussed in the next section.
At an increased resolution level, the greenhouse effect is visible but appears to be even less significant than methane.
The observed greenhouse effect impacts of methane and nitrous oxides relative to carbon dioxide should be considered when they are compared. The Intergovernmental Panel on Climate Change (IPCC), Environmental Protection Agency, and New York State Value of Carbon guidance all use the global warming potential (GWP) to enable intercomparison of greenhouse gases. Happer & van Wijngaarden explained that this parameter is calculated based on per-molecule forcings in a hypothetical, optically thin atmosphere, where there is negligible saturation of the absorption bands, or interference of one type of greenhouse gas with others. In other words, global warming potential values are based on molecular theory with multiple technical simplifications and are not based on observations of the physical properties of the atmosphere.
Table 2 in the New York State Value of Carbon guidance document specifies the Global Warming Potential (GWP) values used in New York. The IPCC 100-year GWP values for methane indicate that using this methodology that methane exacerbates the greenhouse effect 28 times more than carbon dioxide and nitrous oxides are 265 times worse. New York’s vilification of methane is even worse because the law specifically mandates that the 20-year GWP values be used. The 20-year GWP methane value claims that methane is 84 times worse than carbon dioxide. The van Wijngaarden & Happer paper proves that those estimates are incorrect.
|Table 2: Physical Properties of Example Greenhouse Gases (IPCC Fifth Assessment Report)|
|Greenhouse gas||Lifespan (years)||100-YEAR GWP||20-YEAR GWP|
|Carbon dioxide (CO2)||~10045||1||1|
|Nitrous oxide (N2O)||121||265||264|
|Sulfur hexafluoride (SF6)||3,200||23500||17500|
There are other physical properties of the real atmosphere ignored in the global warming potential approach to methane. GWP does not consider actual concentrations in the atmosphere. Carbon dioxide concentrations were 415 ppm in 2021 while methane concentrations are less than 2 ppm and nitrous oxides concentrations are even less. . Molecules in tiny concentrations have less effect and that is not considered. Finally, there is no recognition that the methane atmospheric residence time is only 12 years so it does not accumulate like carbon dioxide.
In summary, the van Wijngaarden & Happer analysis used many measurements of the observed greenhouse effect to develop a general relationship that can be used to predict the effect of increasing concentrations of greenhouse gases. The paper shows that show that increased CO2 will have a modest and decreasing effect on the greenhouse effect if concentrations are doubled. The primary driver of this observation is the saturation effect. New York Climate Act guidance for methane is based on claims that methane has a more potent impact on the greenhouse effect than carbon dioxide. However. that guidance is based on a molecule-by-molecule relationship that does not account for the situation in the atmosphere. van Wijngaarden & Happer’s relationship proves that increased atmospheric concentrations of methane and nitrous oxides will have an imperceptible effect on the overall greenhouse effect. For methane the reality of the infrared absorption curve is that the wavelengths where it enhances the greenhouse effect are much smaller than the peak of the curve where CO2 affects it. Finally, there are some physical properties of the real atmosphere related to the greenhouse effect that mean that the potential impact of methane and nitrous oxides are much less than CO2 so the global warming potential approach is invalid. Also note that methane and nitrous oxide emissions are far lower than CO2 emissions so the likelihood that their atmospheric concentrations could substantially increase in the atmosphere is nil.
Sheahen points out there are also scientific implications. He argues out that agreement between theory and experiment is the hallmark of good science and states that the method of van Wijngaarden & Happer meets that criterion. The IPCC approach in their Global Climate Models consistently over-estimates the greenhouse effect so the model predicts too high temperatures as compared to observations. Thus, their approach does not meet the good science criterion.
I hope my attempt to explain this important paper is understandable. I have two conclusions based on the analysis. On one hand the theory that human emissions of greenhouse gases are the primary driver of climate change because of the greenhouse effect is causing an existential threat is widely accepted. However, I agree with Richard P. Feynman’s quote: “It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.” The experimental evidence compiled by Wijngaarden & Happer does not agree with the theory that human emissions of greenhouse gases substantially affect atmospheric warming. The existential threat theory is unsupportable.
Viewed through a pragmatic lens, the New York obsession with eliminating natural gas is irrational. Increased use of natural gas has been responsible for the majority of electric generation emission reductions observed in the state. Natural gas provides efficient, resilient, and safe energy to homes and businesses. Not so long ago the idea that natural gas could also be used a bridge fuel until the aspirational “green” generating resources and energy storage technologies could be tested at the scale needed, perform like a natural gas fired generating unit, and provide power at a similar cost, was generally accepted as a rational approach. Unfortunately, the Climate Act does not allow this approach. The analogy for skipping the need for a bridge fuel is that proponents want to jump out of a perfectly good airplane without a parachute because they assume that the concept of a parachute will be developed, proven technically and economically feasible, and then delivered in time to provide a soft landing. This paper shows that there isn’t even a valid reason to jump out of the airplane.