For the past 35 years, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) has warned us that emissions from the burning of fossil fuels, predominantly carbon dioxide (CO2), are causing dangerous global warming.  This myth is blindly accepted — even by many of my science colleagues who know virtually nothing about climate.  As a scientist, my purpose here is to help expose this fairy tale.

The global warming story is not a benign fantasy.  It is seriously damaging Western economies.  In January 2021, the White House ridiculously declared that “climate change is the most serious existential threat to humanity.”  From there, America went from energy independence back to energy dependence.  Another consequence has been the appearance of numerous companies whose goal is to “sequester CO2” as well as “sequester carbon” from our atmosphere.  However, this so-called “solution” is scientifically impossible.  Life on Earth is based on carbon!  CO2 is plant food, not a pollutant!

Generations have been brainwashed for decades into believing this imaginary “climate crisis,” from kindergarten through college, and in mainstream media and social media.  Indoctrinated young teachers feel comfortable teaching this misinformation to students.  Dishonest climate scientists feel justified in spreading disinformation because they need governmental support for salaries and research.

The evidence contradicting the climate apocalypse is vast.  Some comes from analysis of Greenland and Antarctica ice, in which air trapped at various depths reveals CO2 levels of past climate.  Proxy records from marine sediment, dust (from erosion, wind-blown deposition of sediments), and ice cores provide a record of past sea levels, ice volume, seawater temperature, and global atmospheric temperatures.

From his seminal work while a prisoner of war during WWI, Serbian mathematician Milutin Milankovitch explained how climate is influenced by variations in the Earth’s asymmetric orbit, axial tilt, and rotational wobble — each going through cycles lasting as long as 120,000 years.

It is widely recognized that Glacial Periods of about 95,000 years, interspersed with Interglacial Periods of  approximately 25,000 years, correspond with Milankovitch Cycles.  Multiple incursions of glaciers occurred during the Pleistocene, an epoch lasting from about 2.6 million to 11,700 years ago, when Earth’s last Glacial Period ended.  Around 24,000 years ago, present-day Lake Erie was covered with ice a mile thick.  

Within each Interglacial Period, there’ve been warming periods, or “Mini-Summers.”  For example, within the current Holocene Interglacial, there have been warmer periods known as the Minoan (1500–1200 B.C.), Roman (250 B.C.–A.D. 400), and Medieval (A.D. 900–1300).  Our Modern Warming Period began with the waning of the Little Ice Age (1300–1850).  Today’s Mini-Summer is colder so far than all previous Mini-Summers of the last 8,500 years.

How did CO2 get blamed for global warming?  French physicist Joseph Fourier (1820s) proposed that energy from sunlight must be balanced by energy radiated back into space.  Irish physicist John Tyndall (1850s) performed laboratory experiments on “greenhouse gases” (GHGs), including water vapor; he proposed that CO2 elicited an important effect on temperature.  However, it’s impossible to do appropriate experiments — unless the roof of your laboratory is at least six miles high.  Swedish chemist Svante Arrhenius (1896) proposed that “warming is proportional to the logarithm of CO2 concentration.”  Columbia University geochemist Wallace Broecker (1975) and Columbia University adjunct professor James Hansen (1981) wrote oft-cited articles in Science magazine, both overstating the perils of CO2 causing dangerous global warming — without providing scientific proof.

Most of Earth’s energy comes from the sun.  Absorption of sunlight causes molecules of objects or surfaces to vibrate faster, increasing their temperature.  This energy is then re-radiated by land and oceans as longwave, infrared radiation (heat).  Princeton University physicist Will Happer defines a GHG as that which absorbs negligible incoming sunlight but captures a substantial fraction of thermal radiation as it is re-radiated from Earth’s surface and atmospheric GHGs back into space.

The gases of nitrogen, oxygen and argon — constituting 78%, 21%, and 0.93%, respectively, of the atmosphere — show negligible absorption of thermal radiation and therefore are not GHGs.  Important GHGs include water (as high as 7% in humid tropics and as little as 1% in frigid climates), CO2 (0.042%, or 420 parts per million [ppm] by volume), methane (0.00017%), and nitrous oxide (0.0000334%, or 334 ppm).  Water vapor (clouds) has at least a hundred times greater warming effect on Earth’s temperature than all other GHGs combined.

As atmospheric CO2 increases, its GHG effect decreases: CO2’s warming effect is 1.5°C between zero and 20 ppm, 0.3°C between 20 and 40 ppm, and 0.15°C between 40 and 60 ppm.  Every doubling of atmospheric CO2 from today’s levels decreases radiation back into space by a mere 1%.  For most of the past 800,000 years, Earth’s atmospheric CO2 has ranged between about 180 ppm and 320 ppm; below 150 ppm, Earth’s plants could not exist, and all life would be extinguished.

Today’s global atmospheric CO2 levels are ~420 ppm.  Even at these levels, plants are “partially CO2-starved.”  In fact, standard procedures for commercial greenhouse growers include elevating CO2 to 800­–1200 ppm; this enhances growth and crop yield ~20–50%.  As shown by satellite since 1978, increased atmospheric CO2 has helped “green” the Earth by more than 15 percent, substantially enhancing crop production.

If global atmospheric CO2 was ~280 ppm in 1750, and it’s ~420 ppm today, what’s the source of this 140-ppm increase?  Scientists estimate that human-associated industrial emissions might have contributed 135 ppm — with “natural causes” accounting for the remaining 5 ppm.

In Earth’s history, the highest levels of atmospheric CO2 (6,000–9,000 ppm) occurred about 550–450 million years ago, which caused plant life to flourish.  CO2 levels in older nuclear submarines routinely operated at 7,000 ppm, whereas newer subs keep CO2 in the 2,000- to 5,000-ppm range.  Meanwhile, ice core data over the last 800,000 years show no correlation between global warming or cooling cycles and atmospheric CO2 levels.

CO2 in our lungs reaches 40,000–50,000 ppm, which induces us to take our next breath.  Each human exhales about 2.3 pounds of CO2 per day, which means Earth’s 8 billion people produce daily 18.4 billion pounds of CO2.  But humans represent only 1/40 of all CO2-excreting life on Earth.  Multiplying 18.4 billion pounds by 40 gives us 736 billion pounds of CO2 per day.  This approximates the overall CO2 excreted by the total animal and fungal biomass on the planet.

Daily emissions from worldwide industry in 2020 were estimated to be 16 million metric tons of CO2 equivalents.  If one metric ton is 2,200 pounds, then “total industrial emissions” amount to 35,200,000,000 (35.2 billion) pounds of CO2 per day.  This means that the entire animal and fungal biomass (736 billion pounds) puts out more than 20 times as much CO2 as all industrial emissions (35.2 billion pounds)!

Can any clear-thinking person comprehend the facts above and still create a company with idiotic plans to “sequester CO2” or “sequester carbon”?  Scientifically, “net zero” and “carbon footprint” are meaningless terms.  There is no “climate crisis.”

If you try to find these facts on the web, good luck!  Out of every 10 hits on any climate topic, you’ll be lucky to find one or two sites with truthful scientific data.

The door of a nearby classroom displays a poster of Abraham Lincoln with the caption: “Don’t believe everything you read on the internet.”  It is advice that our 16th president surely would have offered — had he lived to see the rise of this global warming quasi-religion.

Daniel W. Nebert is professor emeritus in Gene-Environment Interactions at the University of Cincinnati.  He thanks Professor Will Happer (one of the CO2 Coalition directors) for valuable discussions.

Image: Marco Verch Professional Photographer and Speaker via Flickr, CC BY 2.0.