H. Douglas Lightfoot and Gerald Ratzer published their paper Reliable Physics Demand Revision of the IPCC Global Warming Potentials in Environmental Science April 15, 2024. Excerpts in italics with my bolds and added images. H\T Patrick Moore.
Abstract
The Global Warming Potentials (GWP) of the Intergovernmental Panel on Climate Change (IPCC) in Table 2.14 of the Fourth Assessment Report (AR4) show the increase in warming by methane (CH4) and nitrous oxide (N2O) is 21 and 310 times respectively that of CO2. There has been wide acceptance of these values since publishing in 2007. Nevertheless, they are inaccurate.
This study uses accurate methods to calculate the impacts of CO2, CH4, and N2O on the warming of the atmosphere. For example, this quantitative analysis from reliable physics shows the contribution of CO2 to warming at Amsterdam is 0.0083°C out of a difference of 26°C. The warming effect of CH4 on the Earth’s atmosphere is 0.408% of that of CO2, and the warming by N2O is 0.085% of that of CO2.
Thus, the warming effects of CO2, CH4, and N2O are too small to measure. The invalidity of the methane and nitrous oxide values indicates the GWPs of the remaining approximately sixty chemicals in the Table 2.14 list are also invalid. A recommendation is that the IPCC consider revising or retracting the GWP values in Table 2.14.
Introduction
The purpose of this paper is to examine the Global Warming Potentials (GWPs) in Table 2.14 of the Fourth Assessment Report [1] of the Intergovernmental Panel on Climate Change (IPCC), Figure 1.The Global Warming Potentials (GWP) of methane and nitrous oxide calculated by the IPCC in Table2.14 have profoundly affected the decisions made by elected officials worldwide.
Nitrogen fertilizers have been restricted or banned in several countries because they emit a small amount of nitrous oxide. Nitrogen fertilizers are essential for the growth of plants, and nitrogen is often the limiting nutrient [2]. Restricting their use affects food production adversely and can cause food shortages. The IPCC claims that nitrous oxide has up to 310 times the warming effect of CO2. This value is so significant that we must determine whether or not this value of 310 is valid.
A similar situation occurs with methane, which is claimed to have 21 times the warming effect of CO2. Natural gas is virtually all methane transported widely by pipelines and pumping stations. The claim is that methane leaks from natural gas pipeline systems and processing are warming the Earth. Periodically, a scientist will quote Table 2.14 and raise the alarm about methane and the possibility of significant methane releases from the Arctic Tundra caused by the warming of the Earth [3].
The methodology of this study answers the question: “Of the temperature difference between two weather stations, how many degrees Celsius do CO2, CH4, and N2O contribute?” Four weather stations—Pond Inlet, Amsterdam, Colorado Springs, and Princeton, NJ—were selected to provide the answers. The temperature and relative humidity are recorded within the same.
Calculations for Table 2 Column D
In Row 5, the grams of CO2 per kilogram (kg) of dry air is (0.00041806 x 44 x (1000/29) = 0.630, where 44 and 29 are the molecular weights of CO2 and air, respectively. In Row 9, the grams of CH4 per kg of dry air are (0.000001927 x 16 x (1000/29)) = 0.001063, where 16 is the molecular weight of methane. Similarly, in Row 12, Column E, the grams of N2O per kg of dry air are (0.00000033675 x 44 x (1000/29) = 0.000511, where 44 is the molecular weight of nitrous oxide.There are 0.630/0.00106 = 594 grams of CO2 per gram of methane. Thus, there are (594 x 44)/16) = 1634 molecules of CO2 per methane molecule. Thus, because the molecular weights of CO2 and N2O are the same at 44, there are (0.630/0.000511) = 1235 molecules of CO2 for each molecule of N2O in the Earth’s atmosphere. Thus, in September 2023, CO2 molecules outnumber CH4 molecules by 1634 and N2O molecules by 1235.
Measuring the Contribution of CO2, CH4 and N2O to Temperature in the Earth’s Atmosphere
It is essential to understand that the measured and recorded temperature is the sum of all the factors affecting Earth’s temperature. These include warming caused by radiation from the Sun absorbed by CO2, CH4, N2O, feedback, and other warming or cooling effects. These factors also apply to temperature differences. The recorded temperature is input to the Humidair psychrometric program, which includes these factors in the heat content (enthalpy) and specific volume.
The following method quantifies the contribution of carbon dioxide, methane, and nitrous oxide to the difference in temperature between three weather stations and Pond Inlet.Table 3 is a summary of the Excel calculations. The file for the Excel calculations is: “Excel calculations for GWP Mar 102024.xlsx.” From the Excel spreadsheet, Column H, the temperatures measured at Pond Inlet, Amsterdam, Colorado Springs, and Princeton on December 30, 2023, were -18°C, 8°C, 3°C, and 4°C, respectively. We set the recorded level of CO2 at 418.06 at the location with the lowest of the four temperatures, i.e., at Pond Inlet. This is because the number of molecules of CO2 per cubic meter falls as the temperature rises.
The grams of CO2 per kg of dry air in the Pond Inlet row of Table 3 are the same as in Column D of Table 2. The temperature contributions of CO2, CH4, and N2O to the difference in temperature in °C between Pond Inlet and the weather stations in Column A are in Columns G, H, and I. The total is in Column J. The upper lines in the titles of the columns are the locations in the Excel spreadsheet calculations. Note that the average CO2 for Table 2 was 418.06 in August 2023, and the level of CO2 during the recording of the values for the Excel spreadsheet was 422.3 ppm. The difference of 4.24 ppm has no significant effect on the results of this study.
As shown in Table 4, the temperature increase caused by CH4 and N2O is a small percentage of the temperature rise caused by CO2.The warming effect of CO2 is too small to measure [9, 10].Thus, the warming effects of CH4 and N2O are also too small. The data in IPCC Table 2.14, showing that CH4 has 21 times the warming effect of CO2 and that N2O has 310 times the warming effect of CO2, are grossly incorrect.
Summary and Conclusions
This study provides evidence that the IPCC Global Warming Potentials are incorrect. It starts with the levels of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) measured as molecules per million molecules of dry air, which is the molar fraction. Then, quantitative results from reliable physics establish the enthalpy and specific volume at four weather stations. Chemistry determines the grams of each gas per kg of dry air. The increase in the temperature bycurrent levels of methane (CH4) and nitrous (N2O) in the Earth’s atmosphere isa small percentage of that of CO2.Conclusions 6.1, 6.2, and 6.3 answer, “Of the temperature difference between two weather stations, how many degrees Celsius do CO2, CH4, and N2O contribute?”
6.1.In this study, the difference in temperature between Pond Inlet and Amsterdam is 26°C. The contribution of CO2 to this difference is 0.0083°C, but this amount is too small to measure.
6.2.The contribution of CH4 to the 26°C difference between Pond Inlet and Amsterdam is 0.0000338°C.This current level of methane in the atmosphere increases the temperature by 0.408% of that of CO2. It does not have 21 times the warming of CO2 as claimed by the IPCC.
6.3.N2O’s contribution to the 26°C difference between Pond Inlet and Amsterdam is 0.00000705oC. This is 0.085% of that of CO2. It does not have 310 times the warming of CO2, as claimed by the IPCC
6.4.The total contribution of all three gases to the 26°C difference between Pond Inlet and Amsterdam is 0.00833oC. This is a typical result; this difference is too small to measure.
6.5.The warming of the Earth’s atmosphere by CH4 and N2O is 0.408% and 0.085% respectively of that of CO2.
6.6.The warming by CH4 and N2O is so tiny in the Earth’s atmosphere that the IPCC estimates of warming by GWP over several years are irrelevant.
6.7.It is reasonable for the IPCC to consider revising or withdrawing Table 2.14 in the Fourth Assessment Report
Footnote:
If like me you are new to the term “psychrometrics”, it refers to an engineering method for assessing the thermodynamic properties of moist air. From Understanding The Psychrometric Chart
The psychrometric chart is a tool commonly used in the field of engineering to understand and analyze the properties of air. This chart provides valuable information about the thermodynamic properties of moist air, which is crucial for various applications such as heating, ventilation, and air conditioning (HVAC) systems. By understanding the psychrometric chart, engineers can make more informed decisions and optimize their designs for enhanced efficiency and comfort.
In addition to temperature, the psychrometric chart also includes other properties such as humidity ratio, enthalpy, and specific volume. The humidity ratio represents the mass of moisture present in the air per unit mass of dry air, while enthalpy is the total heat content of the air including both sensible and latent heat. Specific volume, on the other hand, is the volume occupied by a unit mass of air. Together, these properties provide a comprehensive understanding of the thermodynamic behavior of moist air.
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May 12, 2024 at 12:17PM
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