Comment on: “Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate”

Robert W. Endlich

[This is the author’s review of the Impacts of Greenhouse Gas Emissions on the US Climate, which he submitted to Regulations.gov in the necessary format.  Also, this is his post corresponding to his August 2025 Forum presentation.  Ed.]

INTRODUCTION

I received a Bachelor’s in Geology, Rutgers, 1962, Basic Meteorology certificate from Texas A&M, 1964, and an MS in Meteorology at The Pennsylvania State University, 1969. I served as a Weather Officer in the US Air Force for 21 years, 1963-1984, including overseas tours on Guam, in Thailand and Viet Nam, and in Germany, during the Cold War. In 1964, I was elected to Chi Epsilon Pi, the National Meteorology Honor Society, while an Air Force Basic Meteorology student at Texas A&M University. I worked as a Meteorologist for 49 years: 21 in the Air Force, 18 in the U.S. Army Atmospheric Sciences Laboratory, White Sands Missile Range, NM, and 10 in the Physical Science Laboratory at New Mexico State University. In later years I have been a principal in the Cruces Atmospheric Sciences Forum, a climate study group in Las Cruces, NM. Many of my contributions are on that group’s Web Site at https://casf.me/.

BACKGROUND:  I am commenting on FR Doc # 2025-14519

NOTATION CONVENTION: When a chemical name is in brackets, e.g., “<CO₂> PPM,” understand this as “atmospheric concentration of CO₂, in Parts per Million.”

ANALYSIS

The claim by many Global Warming Adherents as well as some who published the DOE Report, “Climate Working Group (2025) A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate,” Washington DC: Department of Energy, July 23, 2025, seems to have missed at least three critical elements showing that today’s CO₂ emissions do NOT CONTROL earth’s temperature.

ONE

Most of the data quoted in the DOE report and others is from the period of time subsequent to “The Great Climate Shift of 1976.”

Let’s consider pertinent data before 1976.

According to the EPA (https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data?mc_cid=2c4080c62f&mc_eid=6d17b006b3), from 1946-1976, emissions of CO2 ~tripled, from ~5 GT/year (1946) to ~15 GT/ year (1976) over that time.

Yet, temperatures PLUMMETED over that time, giving the technical and popular literature numerous stories of significant cooling and a “coming Ice Age.” The Northern Hemisphere Temperature time series plots in Fig 3 of Hansen et al, “Climate Impact of Increasing Carbon Dioxide,” SCIENCE, 28 Aug 1981, Vol 213, No 4511, https://casf.me/wp-content/uploads/2019/01/PDF_Climate-Impact-of-Increasing-Atmospheric-Carbon-Dioxide_Science__28_August_1981_Hansen81_CO2_Impact.pdf shows this distinctive fall in temperature.

Figure 1 shows time series of CO₂ Emissions from the EPA, top, and the Hansen, et al plot of northern Hemisphere temperatures, below.

From the technical literature of the time, in Monthly Weather Review, “Global Temperature Variation, Surface-100 mb, An Update into 1977,” by Angell, J. K. and J. Korshover, Vol. 106, No. 6, June 1978: Figure 2 (Fig. 4 in the referenced article) shows Time Series from 1955-1975 decreasing temperatures at the Surface in the Northern Hemisphere, Southern Hemisphere, and Globally. That same Figure 2 displays more time series over the same dates, 1955-1975, all of which show a distinct drop in temperatures at the surface, and at numerous levels aloft, to 100 mb, about 53,000 ft.

From the popular literature of the time, these print articles:

TIME, Monday, 24 Jun 1974, “Another Ice Age?” One of the paragraphs leads:

“Since the 1940s the mean global temperature has dropped about 2.7° F.”

NEWSWEEK, 28 Apr 1975, in the SCIENCE section: “The Cooling World.” Some quotes:

“But there is a peril more immediate than the prospect of another ice age. Even if temperature and rainfall patterns change only slightly in the near future in one or more of the three major grain-exporting countries—the U.S., Canada and Australia —global food stores would be sharply reduced.”

NEW YORK TIMES, Thursday, Aug 8, 1974, “Climate Changes Endanger World’s Food Output,” by Harold M. Schmeck, Jr. Accompanying the article there is a global map, with black color covering areas of the Earth with conditions “threatening future (food) output.”

DER SPIEGEL, 12 Aug 1974, “Catastrophe in Installments,” Leading paragraph in bold:

“Is a new ice age coming? Not right away, but the rainy summer in Northern Europe, climate researchers fear, was only part of a worldwide change in weather – a preview of cooler and wetter times to come.” <Translated by my daughter, High School German teacher, Cathy Gamble>

SCIENCE NEWS, 1 March 1975, “THE ICE AGE COMETH?” Cover art featured a glacier pushing from Mid-Town south to lower Manhattan.

TIME, 31 Jan 1977, article title on the cover, “The Big Freeze,” cover shows photo of a man in a red knit hat covering all of his head and neck, except nose and eyes, snow on the knit hat over his head and throat.

TIME Cover from 1979, date obscured, Couple huddled in front of Christmas Tree and next to radiator, “The Cooling of America 1979,” on page fold in green: story title, “A Challenge to Khomeini.”

TV short, from the “In Search of” TV series, “In Search of The Coming Ice Age,” https://www.youtube.com/watch?v=1kGB5MMIAVA

TWO

There is a second data set showing presumptions that CO₂ emissions and concentrations control Earth temperatures are fundamentally wrong.

For this we need to look at the data from the Vostok Ice Cores in Antarctica: http://en.wikipedia.org/wiki/File:Vostok-ice-core-petit.png, in Figure 3, below.

In this data plot, variations from present Temperature are plotted in blue, while <CO₂> is plotted in green.

There are five interglacial periods in this plot, each numbered as a Marine Isotope Stage, or MIS, and mentioned briefly below, plotted left to right.

<The original definition of Marine Isotope Stages comes from Lisiecki, L.E, and M.E. Raymo in “A Pliocene-Pleistocene stack of 57 globally distributed benthic Delta18 O records,” PALEOCEANOGRAPHY, VOL. 20, PA1003, 2005. >

On the left, plotted in blue, are temperature changes in the current interglacial, MIS 1, the past 10,000 or so years, frequently called the Holocene. Today <CO₂> is now over 425 Parts per Million, PPM, accessed from https://www.co2.earth/ on 19 Aug 2025. Today’s <CO₂> 425 PPM would be off scale high, but today’s temperatures are at the Zero mark in Figure 3.

Next to the right is the interglacial MIS 5, about 140,000 years ago, distinctly warmer than the present, <CO₂> 270 PPM,

Next is the interglacial MIS7, about 240,000 years ago, distinctly warmer than the present <CO₂> briefly 280 PM,

Next is the interglacial MIS 9, about 340,000 years ago, distinctly warmer than the present, <CO₂> 290 PPM,

Last, furthest right, MIS 11, about 410,000 years ago, with a mean temperature warmer than the Holocene and <CO₂> 280 PPM.

At this point the reader should ask the question: How at present, with CO₂ <425> PPM, could the present temperatures be 2.5C COLDER than the Eemian 140,000 years ago, MIS 5, which had CO₂ of <270> PPM?

There is only one answer: <CO₂> clearly does not control temperature.

Below, in the close-up plot, are the Holocene temperatures for the past 10,000 years. https://casf.me/wp-content/uploads/2025/08/Bringing-us-up-to-date-on-Trump-Energy-Department_s-Effort-to-Repeal-Obama_s__Endangerment-Finding__16-AUG-2025.pdf, slide 37.

Zero years before present marks the present temperature and the blue temperature plot shows many temperature changes of +/- 1.5C. There are also temperature excursions of +/- 2C.

The next rhetorical question to be asked is,

“How can the Climate Alarmists be so certain that THIS LATEST temperature fluctuation is a CATASTROPHIC ONE?”

Just looking at the chart, the question answers itself. There is nothing unusual about the present temperature or rate of change of temperature. There are no temperature changes which could be deemed “unusual,” or “catastrophic.”

Notice the temperature trace never flat-lines. Temperature change, or “Climate Change” is always happening. The “never in stasis” characteristic is visible in all temperature time series. Temperature changes of +/- 1.5C are a typical range which has occurred numerous times in the past 10,000 years.

Please note again, referring to Figure 3, that the present interglacial is by far the COLDEST of the five interglacials displayed in the last 410,000 years, despite the present <CO₂>being off scale high, over 425 PPM.

Another rhetorical question:

“How could CO₂ emissions and <CO₂>, now 425 PPM, be a problem for earth residents and the climate when the present temperature is not even close to being the warmest of the present interglacial?”

Figure 4 above shows the maximum temperature of the present interglacial occurred some 8,000 years ago.

Again, Ice Core reconstructions of temperature from the Vostok Ice Cores show numerous fluctuations of +/- 1.5C; there are no reasons to think the present increase in temperature from the depth of the Little Ice Age two centuries ago is in any way leading to the climate catastrophe proclaimed by the climate alarmist community.

From New Astronomy, the 1 Aug 2016 journal article by Yndestad, Harald and J.E. Solheim, “The Influence of Solar System Oscillation on the Variability of the Total Solar Irradiance.” Their plot of Total Solar Irradiance, TSI, 1700-2023, is just below.

Figure 5. From Yndestad and Solheim, 2017, reconstructed Total Solar Irradiance from 1700 to 2023. Note particularly the temperature drop in the post-WW2 period, starting shortly before 1950 and extending to the 1970s. Simultaneously the world experienced the Post-WW2 Economic Boom, when CO₂ emissions tripled.

There appear to be major swings of TSI, perhaps every 60 years, and the TSI reconstruction shows frequent minor changes in the direction of the TSI trace, seemingly annually.

A close-up of the period 1845-2013 is in Soon, W. and W.M. Briggs, 2012, in https://www.researchgate.net/figure/Solar-irradiance-and-daytime-high-temperatures-versus-time-for-the-contiguous-United_fig3_261099608,  their figure 2.

Figure 6 below shows that next close-up of TSI in Black, and the Berkeley Earth Surface Temperatures in Gray. The message from the data clearly is,

“Earth Temperature changes are caused by changes in Total Solar Irradiance, TSI.”

The data plotted in Figure 6 are significant; they show prominently the dramatic drop in temperature from 1940-1976, in Gray, accompanied by a significant drop in TSI from 1950-1970, in Black. During this time, CO₂ emissions tripled.

Readers and scientists alike must take from these data that during the post-WW2 time frame, from the mid-1940s to the mid-1970s, despite the tripling of CO₂ emissions, temperatures fell as TSI fell. This means that CO₂ emissions did not control temperatures, TSI controlled temperatures.

THREE

Permit me to ask another rhetorical question:

“Has Henry’s Law been repealed?”

High School and College students of Chemistry should learn Henry’s Law, named for William Henry, British chemist.

Loosely, where temperatures and pressures in the water and air are those commonly found at Earth’s surface,

“The amount of dissolved gas in a liquid is directly proportional at equilibrium to its partial pressure above the liquid.”

Worthwhile information on this topic is on our web site at https://casf.me/wp-content/uploads/2017/10/PDF_-Climate-Short_Henry_s-Law-from-175-years-ago_Temperature-Controls-CO2_15-Sep_2017.pdf

There are several publications demonstrating that as sea water warms up, FIRST the sea water temperature increases, THEN the atmospheric <CO₂> increases. In Humlum, et al, “The phase relation between atmospheric carbon dioxide and global temperature,” https://www.researchgate.net/publication/257343053_The_phase_relation_between_atmospheric_carbon_dioxide_and_global_temperature , Humlum’s Figure 3 shows this feature: FIRST the sea water temperature increases, THEN the atmospheric <CO₂> increases. Clearly TEMPERATURE controls <CO₂>. Not the reverse.

Another pertinent diagram is on the CASF web site, https://casf.me/wp-content/uploads/2017/10/PDF_-Climate-Short_Henry_s-Law-from-175-years-ago_Temperature-Controls-CO2_15-Sep_2017.pdf.  is the top diagram from Carbon Sense: https://carbon-sense.com/category/the-evidence/ ; it shows an EPICA Dome C Ice core analysis from Antarctica.

This Carbon Brief graphic plots blue dots, the time series of temperatures, and red dots, the time series of CO₂ from that ice core. From the left, FIRST the temperature increases, THEN, later, the CO₂ increases. There are four separate demonstrations plotted, showing that TEMPERATURE controls CO₂, not the reverse.

RECOMMENDATION

The EPA and the DOE need to remove notions in their literature that say or imply that emissions of Carbon Dioxide or present concentrations of Carbon Dioxide are an “endangerment” to humans in the USA (or indeed, globally).

US Government publications purporting to show that increasing CO₂ emissions and increasing <CO₂> control Earth temperatures are incorrect, and should be republished to show that temperatures follow Total Solar Irradiance, TSI, not <CO2>.

We showed here that increased TSI, not  CO2, caused temperatures to increase after the Great Climate Shift of 1976. Increasing concentrations of atmospheric CO₂ clearly do NOT cause increasing temperatures, otherwise, this would be the warmest interglacial of the past 410,000 years. The analysis here further cements the notion that increasing concentrations of atmospheric CO₂ is NOT the human endangerment proposed by the Obama Administration in 2009.

CONCLUSIONS

ONE

This paper shows that before the Great Climate Shift of 1976, as emissions and concentrations of CO2 increased, Earth’s temperatures fell. There was rampant speculation in the popular press that a “New Ice Age” was imminent.

After 1976, and after TSI significantly increased, temperatures increased. (this is when, on 23 Jun 1988, EPA’s James Hansen mistakenly testified to the Senate, “The greenhouse effect has been detected, and it is changing our climate now.”) It appears that Hansen did not understand that the increasing temperatures were caused by increasing TSI, not increases in <CO₂>.

The proposal in the 2009 Endangerment Finding and other analyses of <CO₂> vs. Temperature ignore the very plain data from 1946-1976 which show that as emissions of CO2 tripled, temperatures plummeted. This was published in the technical literature, was on TV, and also published in the popular print literature, which decried “The Coming Ice Age.”

TWO

Examining the Vostok Ice Cores, we see among temperatures of the past 410,000 years five interglacials, warm periods among this mostly glacial time of Earth History. The present interglacial, also called the Holocene or MIS 1, now has <425> PPM CO₂, but it is clearly the coldest of the five interglacials. The other interglacials, MIS 5, MIS 7, MIS 9 and MIS 11, all have <CO₂> maxima around 280 PPM. Clearly, with all of the CO₂ in the air today, at 425 PPM, this remains the COLDEST of the five interglacials.

THREE

Henry’s Law from Chemistry says that in an aqueous solution, such as sea water containing dissolved air, as the temperature of the water increases, it drives the dissolved gases out of the solution and into the air above until the partial pressures of the gas in the water and the overlying atmospheric partial pressures are equal. The dissolved gases in sea water come from the atmosphere: 78% Nitrogen, 21% Oxygen, 1% Argon and now 425 PPM CO₂. Ole Humlum showed in https://www.researchgate.net/publication/257343053_The_phase_relation_between_atmospheric_carbon_dioxide_and_global_temperature FIRST seawater temperature increases THEN the atmospheric <CO₂> increases as the CO₂ is driven from the ocean water into the atmosphere.

Clearly, statements that CO₂ controls today’s atmospheric temperature and that today’s increasing concentrations of CO₂ cause sharply rising temperatures are incorrect.

Therefore, the Obama Administration’s 2009 claims that today’s emissions of CO₂ are an endangerment to humans because of dramatic climate warming are plainly wrong.