Laws of Physics Define the Insignificant Warming of Earth by CO2


CO2 at Mauna Loa
per kg dry air
psychrometric chart
water vapor

How to Cite

Lightfoot, H. D. ., & Ratzer, G. . (2023). Laws of Physics Define the Insignificant Warming of Earth by CO2. Journal of Basic & Applied Sciences, 19, 20–28.


This study provides temperature estimates about the effect of carbon dioxide (CO2) in warming the Earth’s atmosphere using readily available information. It compares the grams of water vapor per kilogram (kg) of dry air with the number of grams of CO2 per kg of dry air. This comparison is over a year for 20 representative areas of the Earth. It shows the grams of water vapor range from 0.1 to 44.0 times that of CO2. The increased heat content (enthalpy) of the atmosphere by CO2 causes a maximum temperature increase of 0.006oC from the Poles to the Equator. This amount is too small to measure. These quantitative results indicate that the Tropics, representing 39.8% of the Earth’s surface, contain almost three-quarters of the atmosphere’s water vapor. In contrast, the Arctic and Antarctic areas at the Poles have an estimated 0.9% of the atmosphere’s water vapor. Water vapor is the significant greenhouse gas that keeps the Earth from being a frozen planet.


Lightfoot HD, Mamer OA. Back radiation versus CO2 as the cause of climate change, Energy and Environment, Sage Publishing 2017.

Lightfoot HD, Ratzer G. Earth’s Temperature: The Effect of the Sun, Water Vapor, and CO2. Journal of Basic & Applied Sciences 2022; 18: 87-97.

Excel Tutorial for beginners, Excel made easy. Available at:

AccuWeather, About us. Available from:

Gately P. Psychrometric chart celebrates 100th Anniversary: by P. Gatley, P.E., Fellow/Life Member ASHRAE, Table 2. Available at: Psychrometrics-100th-Bday.pdf

van Wijngaarden WA, Happer W. Dependence of Earth’s Thermal Radiation on Five Most Abundant Greenhouse Gases, arXiv:2006.03098v1 [] 4 Jun 2020.

Kiehl JT, Trenberth KE. Earth’s Annual Global Mean Energy Budget, Bulletin of the American Meteorological Society 1997.<0197:EAGMEB>2.0.CO;2

Online Interactive Psychrometric Chart. Available at:

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Technical Resources, Psychrometrics, ASHRAE Psychrometric Chart App. Available at: bookstore/psychrometrics

MegaWatSoft Psychrometric Calculator, HumidAir Excel Add-In v3.1. This program is available for purchase or rental

Practical HVAC, Psychrometry - properties of air. Available at:

Tans P, Thoning K. How we measure background CO2 levels on Mauna Loa, NOAA Global Monitoring Laboratory, Boulder, Colorado, September 2020. Available at:

Global Monitoring Laboratory, Earth System Research Laboratories, Trends in Atmospheric Carbon Dioxide. Available at:

Scripps CO2 program, Mauna Loa Observatory, Hawaii, “monthly_in_situ_co2_mlo.csv”. Available at: [

Clark R. Reject AR6, Ventura Photonics Climate Post 6, VPCP 006.1a. Available at: files/VPCP_006.1_RejectAR6.pdf

Scafetta N. MIP6 GCM Validation Based on ECS and TCR Ranking for 21st Century Temperature Projections and Risk Assessment. Atmosphere 2023; 14(2): 345.

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.