The History of Carbon Dioxide (CO2) in the Climate Change Debate

Amy Lee, Environmental Consultant
Featured Water Professional

There is a book that I wish was required reading for everyone engaging in the climate change debate: “Hot Talk, Cold Science: Global Warming’s Unfinished Debate” by astrophysicist Dr. S. Fred Singer. I have linked to a synopsis of the book on the Independent Institutes website in the references section of this post. I read this book in its first edition (published in 1997) not long after graduating with a Bachelor’s in Geoenvironmental Science and remember it left the following impressions then:

  • The science presented appears to be in-line with all of my college coursework and research.
  • That the human-race is often egotistical when it comes to derivation of solutions from often limited, flawed, biased, or constrained research knowledge.
  • More unbiased scientific research is almost always needed before solutions can be formally proposed, evaluated, funded, and long-term investment can be made. We will not solve problems if we do not follow the science and we base decisions on ideology.

At the point of the publication of the first edition of this book, the Climate Change Debate - (then referred to as the ‘Global Warming Debate’) -  most eyes were focused on the ever-looming hole in the ozone layer of the Earth. This hole was promoted in the media at that time to be something that could destroy earth as we knew it. It was doomsday talk. It was often cited as a reason we were seeing micro-fluctuations in climate events, why skin cancer cases were increasing, and why your beach vacation may need a re-think. The Ozone layer as a matter of fuel for the debate about ‘Global Warming’ disappeared - along with the hole in the Ozone layer.

At that time, I read research papers about solutions to this global problem including dumping things into the atmosphere using a form of ‘cloud seeding’ to close the ozone hole, similar to technologies at the time which were researched to increase rain or snowfall from clouds. My opinion then and my opinion now is that good things rarely come from human intervention in the environment, however, in the case of the Ozone hole it’s probably humans that did fix it, but even that is debatable in science. What we see as a problem might in actuality be normal on Earth’s time-scales, but we often see only on the scale of our own human time-on-earth scales.

A re-read of the 3rd edition (2021) of this book helped me understand a bit more about CO2’s role in the debate including:

  • Since the late 1970’s an increase in governmental policy shifts with the desire to affect climate change have had no appreciable effect on CO2 emissions controls worldwide. As new nations develop, so do CO2 emissions. Therefore, the control of CO2  has a direct influence on the potential economic development of third-world countries as well as potentially positive or negative implications on the environment regionally or globally. It is important to distinguish here between the fact that ‘government policy cannot affect climate change’ versus ‘government policy can affect climate change, however current policies have been ineffective at doing so’. Historic policies have had unnecessary detrimental effects on both the environment or people in certain regions.

  • Lobby organization funding often drives policy which drives the approval for public funding or laws which then fuels (pun intended) more bad policies which further tax societies - potentially unnecessarily or with no net improvement towards what the policy aims to achieve. This results in more control of the economy and society by the government and other sister organizations.

  • Climate change is not a problem of CO2 alone. If we think of all of the variables required to make our atmosphere breathable, water drinkable etc. to allow humans to survive here, it would result in a room full of finely-tuned knobs and levers controlling millions of factors: Truly a fascinating miracle about Earth’s existence as a habitable planet.

  • Natural variables such as water vapor concentrations, solar activity, cloud cover, and ocean health have been left out of the mainstream factors considered when it comes to climate change, even in this 2021 edition.

  • We don’t know what we don’t know. A lot of the data that is being used for the current climate debate and policy changes is fraught with scientific debate, inaccuracies, scientific estimates (i.e., educated guesses), and conspiracy.

  • Until the 1990’s it was generally accepted scientifically that CO2 made up only a small percentage of greenhouse gas effects on climate and water vapor was the more influential factor.

  • More research is needed. We still do not know enough about the CO2 cycle on the planet like how the ocean uptakes CO2, biology mass effects, mineralized storage of carbon, and how other CO2 sinks function. Upon reviewing the geologic history of our planet, it is clear that atmospheric CO2 levels play a role in the climate for the planet, but what is really lacking is an understanding of the sensitivity of the Earth System to changing levels of CO2 and, when does temperature change drive CO2 change, and what is the real role of clouds. We have a pretty good idea how some solar and natural processes offset or reinforce human effects, but quantitative research never hurts. Clouds in particular are the largest fudge factor in trying to predict climate change in climate models. Depending on the situation, clouds can reinforce or oppose global warming.

  • Since 2000, the book indicates that we have not seen appreciable warming trends in any reliable data set although other sources dispute this. The key point of interest is what are the reliable data sets.

We do know from science that:

  • It is generally accepted by scientists that levels of Greenhouse Gases in the atmosphere have increased as a result of human activities. From: CO2 burning of fossil fuels, methane which has doubled in the last 100 from natural and human made activities like landfills – and water vapor and let’s not forget the role of deforestation. 
  • A warming period from 1910 to 1945 was real and not human caused. We still don’t know the exact cause. There are multidecadal climate cycles that can influence climate such as the North Atlantic Oscillation; however, this has not been quantitatively linked to the 1910 to 1945 warming period to create consensus as to why it happened.

  • Warming trends in data from 1978 to 1997 are most likely not correct due to instrumentation used and unreliable data sets including lacking or different calibration methods amongst instrumentation used. Using this as an argument predicting a future warming trend is therefore not precise. It is not the warming trend which is in doubt but the amount and significance. The problem with these earlier measurements is that the measurement methods used back then, while not wrong, are such that it is difficult to correlate their results with results from later instrumentation and measuring methods. Both sets of data indicate a clear upward trend but when you graph the later results with the earlier results, it looks like there is a sudden disjuncture between the two sets (the graph line jumps up while maintaining a similar trend). Another key issue related to measurements is: do we have enough actual data collection points related to atmospheric variables within our global 3-dimension atmosphere and how is the data being corrected to account for the role of the measurement station and surrounding activities on the raw data.

  • Global Climate Models have been used since 1979 to predict future trends. It is known that older models forecast more warming than occurs in real-world observations. Models utilize a fudge factor that assumes a higher sensitivity of climate conditions to CO2 concentration and then link this to anthropogenic factors. In many cases, modeled outputs, not objective facts or real world observation, are driving climate policy. It is important to remember that model output is not actual data and does not validate a hypothesis. A model is a mathematical representation of a hypothesis and models do not generate new data. Modeled output can be used to predict both historic and current conditions but that does not mean that the actual modeled variables used as inputs are correct and we can not forget that temperature increases may trigger more “natural CO2 production”. The challenge here is that historical model sensitivities, instrumentation abilities, and variables selected for study vary from interpretation to interpretation. The goal is always that empirical models fit observable data with new data used to refine the model in order to make it better at making predictions, but when it applies to data, models, and reports that get sometimes overly simplified for policy creation - the reality of the predictions is often lost.

  • There are many benefits to humans in a planet that warms a little including benefits to agriculture.The excess CO2 could be exploited to promote photosynthesis to feed the growing planet, but the potential downside is that opportunistic plants that we classify as weeds may be more agile. The final result may be an increase in overall photosynthesis that may not result in an equivalent level of crop production and this may adversely impact productivity.

  • The most reliable modern climate models for sea level rise data shows a steady increase of about 7 inches per century, but during the global temperature increase from 1910 to 1945, sea level did not rise at this rate indicating there is likely no correlation between air and sea temperatures on sea level rise, yet sea level rise is the main problem cited in mainstream media for solving the “problem” of and driving policies around climate change. In addition to sea level rise we also have erosion and subsidence. We need to spend time actually defining and understanding the root causes for problems before providing funding towards hypothetical solutions. These root causes may have multiple variables that include factors we can and can not control and may be related to past practices, such as paving the planet, building on unstable land, historic filling of wetlands, poor land-use practices, and changing land-use.

The History of the CO2 debate with regard to climate change:

  • In 1824 Joseph Fourier discovered that certain gasses of minor concentrations in the Earth’s atmosphere (like CO2) could prevent the escape of heat (infrared) radiation from the Earth’s surface - like a greenhouse, a concept which became the “Greenhouse Hypothesis.”
  • In 1896 Svante Arrhenius, a chemist, published a paper calculating the potential rise in temperature based on this “Greenhouse Hypothesis.”
  • In 1938 G.S. Callendar, a British steam engineer, asserted that the global temperature rise since the 1890’s was due to CO2; however, other scientists at the time dismissed these ideas.
  • In 1942 a textbook by T.A. Blair “Climatology: General and Regional” states that man does not influence climate except on a local basis for a certain period of time.

  • In 1951 the “Greenhouse Hypothesis” was dismissed by Thomas F. Malone’s research indicated that heat radiation supposedly absorbed by CO2 was already absorbed by water vapor.
  • By 1955 there was not much support for the “Greenhouse Hypothesis” with arguments that the ocean as a carbon sink would instead act like a sponge removing the effects of burning fossil fuels.
  • In 1956 Gilbert Plass, a physicist at Johns Hopkins identified flaws in Malone’s 1951 research that did not account for pressure effects in the atmosphere and pointed out that global temperature increases were of natural causes.
  • In 1957 data by Charles David Keeling and Roger Revelle - “The Keeling Curve” - showed a steady upward trend in CO2 in ice cores that matched pre-industrial concentrations; however the curve combined data from different instruments with different accuracy levels.
  • Also in 1957 Revelle and Suess began investigating the ocean sponge effect of absorbing CO2
  • . Revelle, called “The Father of Greenhouse Warming.” found that much of the fossil-fuel burning products were remaining in the atmosphere and that time would be the grand experiment to reveal the consequences of human effects on the atmosphere.

  • In 1971 a NASA team estimated the ECS (Equilibrium Climate Sensitivity) of CO2 from which they extrapolated that if CO2 were to double in the atmosphere, the global average temperature would increase from 0.6 °C to 0.8 °C over 1,000 years due to water vapor feedback. That feedback would work as follows: more atmospheric CO2 leads to higher temperatures which means the atmosphere can hold more water vapor.  Water vapor, like CO2, is a greenhouse gas so more atmospheric water vapor leads to higher temperatures in a positive feedback loop.
  • A 1975 paper by Revelle pointed out the beneficial effects CO2 has on agricultural yield.
  • From 1975 to 1980 global temperatures began to rise quickly and we still do not know why.
  • In 1978 there was a sense that Global Cooling was the main problem and that a coming Ice Age and return of the Glaciers was the largest threat to humankind on the planet. This was related to the long-term Milankovitch Cycles which were, and still are, promoting global cooling. In North America there was an extremely long and cold winter in 1977-1978. My sister and I were there in Northeastern Pennsylvania! It was a great year for snow forts along with fears of global cooling.
The Author and Sister, Winter 1977-1978

  • In 1979 a National Academy of Sciences Study Group on CO2 determined that the global temperature increase on Earth from a doubling of CO2 would likely not be measurable. However, in combination with water vapor feedback, such a doubling may result in surface temperature increases of 1.5 to 4.5 °C.
  • In the late 1970’s and 1980’s research pointed to the fact that air temperatures in the Northern Hemisphere had been dropping since about 1940. Some scientists thought an ice-age was coming, possibly due to aerosols from burning coal, but this work was largely ignored.
  • In 1980 the global cooling debate was replaced by research fears of global warming but there were still scientists pushing the global cooling hypothesis.  In fact one of the reviewers of this article attended a presentation at Tufts University where a speaker stated that if we do not act now the climate would significantly change and by the year 2020 the state of Pennsylvania would be TUNDRA. (Oram, Brian; 2023).
  • In 1984 Revelle was optimistic, not alarmist, about climate change.
  • In 1988 a very hot summer and drought destroyed crops in the US and during a Senate committee chaired by Al Gore, a NASA scientist, James Hansen, announced he was 99% sure that climate change was here.

  • In 1990-1992 Aerosols came back on the scene in climate change debates.

  • In 1991 Revelle (since deceased) and Singer co-authored an article with Chauncey Starr acknowledging the increase in Greenhouse Gases in the atmosphere, but with much still unknown in climate models to accurately predict the future. This article caught the attention of Al Gore and it became debated whether Revelle actually co-authored it.
  • In 1985-1987 politics took over the climate debate.

  • In 1992 the Earth Summit in Rio de Janeiro saw an updated 1990 Intergovernmental Panel on Climate Change (IPCC) report. At this time President George H.W. Bush brought the US into the debate. The UN’s climate change thinking at the time, called the Framework Convention on Climate Change (FCCC),  was based on Greenhouse Gas theories. FCCC encouraged the spending of trillions of dollars to try to curb climate change against what scientists like Revelle and Singer had indicated would work. Some countries ratified the FCCC at this time others did not.

  • In 1995 the countries that ratified the FCCC met in Berlin and produced a mandate for implementation of the FCCC.

  • In 1996 the countries that ratified the FCCC met again in Geneva and accepted the main conclusion of a “discernible human influence on climate” as final and started to make action plans and emissions controls.

  • The 1997 Kyoto Protocol re-invigorated the 1992 UN Framework Convention on Climate Change (FCCC) policies around CO2 globally, but these policies never reduced CO2 emissions, possibly because the policies were never implemented sufficiently to cause change.

  • Many other meetings between governments on climate policy took place between 1997 and 2015, including the 2015 Paris Agreement meeting.

  • The challenge now is whether it is science driving the facts around these policy agreements or politics and ideology.

Terminology and Acronyms Used:

Acronym Meaning
CO2 Carbon Dioxide - one of several “GHG’s” - see below.
CCS Carbon Capture and Storage
IPCC Intergovernmental Panel on Climate Change
FCCC United Nations Framework Convention on Climate Change
GHG’s Greenhouse Gases (including: Methane (CH4), Carbon Dioxide (CO2), Nitrous Oxide (N2O), Chlorofluorocarbons (CFC’s) etc.)
DOC Direct Ocean Capture
CCUS Carbon Capture Utilization and Storage
DAC Direct Air Capture
ONC Ocean Nourishment Corporation
OAE Ocean Alkalinity Enhancement
sCS2 Single Step Carbon Sequestration and Storage

Some Suggested Reading

Hot Talk, Cold Science: Global Warming's Unfinished Debate

Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters

Global-Warming Alarmists, Skeptics and Deniers: A Geoscientist Looks at the Science of Climate Change

The Beaches are Moving

Sea Level Rise: A Slow Tsunami on America's Shores

Scare Pollution: Why and How to Fix the EPA

Useless Arithmetic: Why Environmental Scientists Can't Predict the Future

The Deliberate Corruption of Climate Science


Sustainable Solutions - Air Pollution (2 CEUS)

Carbon Sequestration Courses (4 PDHs - 2 courses) Subject Area: Environmental (Topic Air Pollution)  


PDH Engineering


Hot Talk, Cold Science (2021)

Biden administration to invest $1.2 billion in projects to suck carbon out of the air

Whatever Happened to the Hole in the Ozone Layer?

Fact-checking the US and China on climate and environment

Fact Sheet: The Bipartisan Infrastructure Deal

‘Down your throat’: Biden pushes CCS on polluted places

Soil Carbon Sequestration: Myths, Realities, and the Biden Administration’s Proposals

Carbon Sequestration

Study reveals uncertainty in how much carbon the ocean absorbs over time

Using the Oceans to Help Capture Carbon

A year in, landmark U.S. climate policy drives energy transition but hurdles remain



Biden Bets Billions on Tech That Sucks Carbon Out of the Air

Global Warming of 1.5 ºC

Carbon Capture

You Asked: Does Carbon Capture Technology Actually Work?

How Carbon Capture Works

Will Carbon Capture and Storage Ever Work?

Carbon Capture and Storage (CCS) Pros and Cons

World's largest plant capturing carbon from air starts in Iceland


1 Point Five | Storage CO2 With Geologic Sequestration

SpaceX is hoping to turn atmospheric CO2 into rocket fuel

Geologic Carbon Dioxide Sequestration Interactive Map

What if space junk and climate change become the same problem?

A Space Elevator for Carbon Dioxide

Proposals Emerge to Transfer Excess Carbon into the Ocean

Scalable Carbon Dioxide Removal for a Safe Climate


Kelp Is Weirdly Great at Sucking Carbon Out of the Sky

Running Tide

Carbon Engineering

Effects of Ocean and Coastal Acidification on Marine Life

Direct Removal of Carbon Dioxide from Oceanwater

A direct coupled electrochemical system for capture and conversion of CO2 from oceanwater

Hydrolytic Softening of OceanWater for Carbon Dioxide Removal

How to pull carbon dioxide out of seawater

Removing Carbon Dioxide Through Ocean Alkalinity Enhancement