The first known instances of humans noticing that we could affect the weather in some way by industrial-type action go all the way back to around the 4th century BC and one Theophrastus. Along with extensive observations about how climate and weather in a given region seems to affect plant life, he also noted how man could change the climate. For example, he observed that a forest that was removed near Philippi ended up seeming to warm the area once all the trees were gone. From this and building on his mentor, Aristotle’s, idea that “nature does nothing in vain and always aims at what is best,” Theoprastus added, “Anything which is contrary to nature is dangerous.”

Of course, deforestation on the scale he was talking about is a drop in the ocean when talking about climate on a global scale and scientists for a couple thousand years since mostly thought the Earth’s general climate had remained largely unchanged since the beginning, outside of things like religious based ideas of mass flooding and the like.

Around the early 19th century, however, the matter began to be revisited. For example, in the 1830s Swiss scientist Louis Agassiz published his groundbreaking work on glaciers. He summed up of his research, “[G]reat sheets of ice, resembling those now existing in Greenland, once covered all the countries in which unstratified gravel (boulder drift) is found; that this gravel was in general produced by the trituration of the sheets of ice upon the subjacent surface”. Thus, contrary to the notion of a stable historic global climate, at some point, things must have been very different from documented history.

With ideas like these gradually gaining steam, scientists the world over started considering what could have possibly caused such a drastic change on a planetary scale.

It turns out the seeds of the solution were already known. For example, going back about a decade before Agassiz’ publication, in 1824, Joseph Fourier of mathematical formula fame, noted that the Earth was warmer than it should be strictly by the solar radiation reaching Earth. He hypothesized that the atmosphere must be allowing the rays through to the surface and radiation from the surface must not be able to pass through some element or elements of the atmosphere back into space as easily.

A few decades later, physicist and inventor Eunice Newton Foote began attempting to quantify in a scientifically rigorous fashion how sunlight warmed various gasses differently. Unfortunately, in 1856, she was barred from presenting her work at the American Association for the Advancement of Science conference owing to the fact that she wasn’t born with a penis. However, thanks to a friend, Smithsonian scientist Joseph Henry, her paper nonetheless got presented without her.

So what did she find? Among other things, compressed air heated more in the sun and likewise the more moisture in the air, the more the heating effect was observed. Significantly, she also found, “the highest effect of the sun’s rays I have found to be in carbonic acid gas [carbon dioxide]… An atmosphere of that gas would give to our earth a high temperature; and if…at one period of its history, the air had mixed with it a larger proportion than at present, an increased temperature from its own action…must have necessarily resulted.”

Expanding on this speculation, a few years after that, Irish scientist John Tyndall demonstrated that various gasses in the atmosphere and their proportions, including water and carbon dioxide, could have been the root cause of drastic changes in climate throughout history, noting in a lecture in October of 1861,

Similar remarks would apply to the carbonic acid diffused through the air, while an almost inappreciable admixture of any of the hydro-carbon vapors would produce great effects on the terrestrial rays, and corresponding changes in climate… Such changes, in fact, may have produced all the mutations of climate which the researchers of geologists reveal.

He expounded upon this in 1863, explaining in a nutshell how this greenhouse effect actually works: “The solar heat possesses the power of crossing an atmosphere, but, when the heat is absorbed by the planet, it is so changed in quality that the rays emanating from the planet cannot get with the same freedom back into space. Thus the atmosphere admits the entrance of the solar heat but checks its exit, and the result is a tendency to accumulate heat at the surface of the planet.”

In other words, sun rays mostly pass through the atmosphere to the surface where they warm it. From there, infrared energy is emitted back up, which is absorbed and emitted by things like water molecules, methane, and carbon dioxide, keeping some of that energy from escaping so readily back into space.

And if you’re wondering on this one, it’s estimated that before the Industrial Revolution, Earth would have been approximately 33 °C (59 °F) cooler if it wasn’t for the greenhouse effect occurring from such elements in the atmosphere- meaning we’d all be living on a bit of a Popsicle planet. Or, more likely, not living at all.

At this point, however, the leading minds of the age generally thought water vapor the dominate element here, with most dismissing the effect of carbon dioxide given its extreme low density in the atmosphere.

Slightly more progress was made, however, thanks to Swiss scientist and Nobel Prize winner Svante Arrhenius who, in 1896, in his own attempt to explain past climate change published a paper with quite extensive calculations that indicated carbon dioxide concentrations in the atmosphere could be a likely culprit, with only a halving or so of the then levels of around 280 parts per million in his estimation potentially resulting in about a 4-5 degree Celsius drop in global temperature. He felt this would be sufficient to cause an ice age.

From there, thanks in part to a colleague, Nils Ekholm’s, 1899 suggestion that the burning of pit coal could ultimately double the amount of carbon dioxide in the atmosphere at some point, Arrhenius went on to theorize what would happen if that occurred. He eventually concluded that this would result in an approximately 5-6 degree Celsius increase in global temperature and that it would take about 3,000 years for man’s industrial emissions to cause such a thing. He further thought this would be a very good thing, stating, “We would then have some right to indulge in the pleasant belief that our descendants, albeit after many generations, might live under a milder sky and in less barren surroundings than is our lot at present.”

That said, few paid much attention to this at the time, with those who would research the matter in the decades following ultimately concluding, to quote Sir George Clarke Simpson, then director of the British Meteorological Office in 1929, “[It is] now generally accepted that variations in carbon-dioxide in the atmosphere, even if they do occur, can have no appreciable effect on the climate.”

So who would finally convince the experts that they were wrong if not a Nobel Prize winner? Well, it turns out, just a random Guy- Guy Callendar, to be precise- collecting data as a bit of a hobby on the side from his day job as a steam engine engineer.

Born on February 9, 1898, Guy was the son of one of the leading scientific minds of the 19th century, physicist Hugh Callendar. Guy’s dear ol’ dad was a man who was called by the “father of nuclear physics”, Ernest Rutherford a “universal genius”. Hugh did everything from inventing the platinum resistance thermometer, which allowed for extremely accurate ultra high temperature measurements, among other things advancing the field of metallurgy, to developing non-scientific things like the Cambridge system of shorthand as a way to making writing more efficient and thus get more studying and research done in the same amount of time.

Thanks to Guy’s father’s extreme success in using his academic talents towards not just advancing science, but inventing things that sold well, Guy grew up in a 22 room mansion and was given, along with his siblings, an extensively equipped laboratory converted, ironically enough given what Callendar would go on to be remembered for today, a greenhouse.

Of course, not all things went swimmingly in his early days as a budding researcher, in part owing to one of his brothers accidentally blowing up the children’s laboratory when he was attempting to make TNT… Also at one point that same brother accidentally blinded Guy in his left eye… Thankfully Guy retained the use of the other eye, which we like to think he nicknamed “Old reliable.”

When he wasn’t getting himself blinded or tinkering away in what was apparently the most badass kid’s lab of all time, after attending Durston House School, Guy apprenticed under his father during WWI, working for the Air Ministry in various research and advancements for the war effort, such as developing an X-ray system for use in analyzing engine blocks to make sure they were free of defect.

Beside that, he also received a degree in Mechanics and Mathematics from the Imperial College, but after abandoned any further formal education, though eventually took the mantle from his dear old dad as the leading steam engine engineer in the UK.

Among other hobbies on the side, including a love of sports, however, he also eventually began collecting weather data. As to why, well, Callendar simply noted, “As man is now changing the composition of the atmosphere at a rate which must be very exceptional on the geological time-scale, it is natural to seek for the probable effects of such a change.”

In short, he was curious.

As he began collecting the data, first, as others had observed, he noticed the global temperature had increased over the last half century or so. He thus began to consider all the various factors that could cause it, including properties of gases in the atmosphere, average sunlight in different regions, ocean currents, etc. etc., attempting to account for every possible variable he could and then figuring out which elements were causing the change and how.

Towards this end, he corresponded with scientists and researchers the world over collecting massive amounts of data from a couple hundred weather stations and performing literally tens of thousands of calculations by hand in his spare time.

By 1937, he was ready to publish his findings. As to what he found, the data showed that carbon dioxide density in the atmosphere had risen from about 274-292 parts per million in the late 19th century, to just over 300 parts per million in the late 1930s. (For reference, it currently stands at just over 400 parts per million today.) Via calculating the estimated amount of carbon dioxide humans were releasing into the atmosphere each year and estimating how much various mechanisms in the ocean and the like could absorb of this, he also found that the rise could be directly attributed to the net-increase from man-made activities. On top of that, when crunching the numbers on the extra infrared absorption this would result in among other factors to consider, it directly correlated to the observed global temperature increase in the half century before his paper was written.

Unfortunately for him and the thousands of hours of his spare time he put into this, nobody cared.

In fact, when he submitted his paper, The Artificial Production of Carbon Dioxide and Its Influence on Temperature, for publication on May 19, 1937, nobody even bothered to look at it until February 16, 1938- almost a year later. Shortly thereafter, in April of 1938, it was published to little fanfare, though he was able to present his research to six climate scientists at the Royal Meteorological Society.

They weren’t impressed. Or, more aptly given the minutes recorded of the discourse after his presentation, which are a quite fascinating read including Callendar’s responses to objections, they were impressed with the amount of effort he clearly put in, as well as the extremely professional way in which he presented the data; they merely thought little of that data and thus the conclusions he came to.

The aforementioned Sir Simpson, who was one of the panel members, also explicitly noted Callendar was a “non-meteorologist”; in essence, he didn’t know enough to know what he was talking about, and all his data showed was a mere coincidence- correlation does not equal causation. And more to the point, they questioned the accuracy of Callendar’s carbon dioxide and temperature measurements in the first place, despite the extreme effort Callendar explicitly went to to reduce the noise in the data and account for the potential error bars.

And if you’re curious just how accurate he was given our more enlightened vantage point and snazzy super computers able to crunch the numbers far more effectively and with massively greater and more accurate datasets, modern estimates from the Carbon Dioxide Information Analyses Center indicate that from 1887 to 1937 the net amount of carbon dioxide added to the atmosphere from mankind’s activities was about 140,000 million tonnes. Callendar, in contrast, sat in his little office in England compiling data from across the globe, using it to make estimates of absorption and emissions, all the while crunching the numbers by hand. His result? 150,000 million tonnes. Presumably if Callendar were still alive today, the revelation of the CDIAC’s number in comparison with his would have resulted in one of the most delayed mic drops in scientific history.

Going back to his presentation, his lone supporter of sorts on the panel, Dr. C. E. P. Brooks, at the least agreed a climate change had been occurring, not just evidenced by temperature data, but a variety of other observable and irrefutable phenomenon, but “did not think that a change in the amount of carbon dioxide could cause such a differential effect.” He did, however, state he thought Callendar’s paper could be a valuable addition to the study of climate change and was worthy of further discussion and research among the wider scientific community to see if perhaps the scientists of the day were incorrect on this point.

Nevertheless, as before, Callendar’s work was largely dismissed and the consensus remained that even if he was correct on his measurements of carbon dioxide and the like, this still was insufficient to cause any measurable change in global temperatures. Something else must have been the real cause, if such a change was occurring.

Undeterred, Callendar, with no outside funding or support, soldiered on… quite literally as not long after he joined the war effort working for the British military during WWII doing things like helping design a fog dispersal system to be implemented in aerodromes in Britain.

Called FIDO, the system worked by warming the air around the air strips using rows of pipes that more or less amounted to giant burners. Key in this system was that it had to use as little fuel as possible to create the desired result and make sure the whole thing didn’t create any smoke. To accomplish both of these things, Callendar was tasked with developing the trench burners, among other elements.

While you might think surely such a system couldn’t work on the scale they needed it to, when the first tests were conducted, they were a rousing success. After the FIDO system was lit, mere moments later the fog dissipated around the aerodrome, allowing Allied planes to come in and land safely. Once switched back off, the protective fog quickly enveloped the aerodrome as the ambient temperature and the dew point once again met, keeping the site from the prying eyes of enemy bombers.

When Callendar wasn’t working on systems like this for the war effort, on the side he continued his research, collecting more and more data that continued to show that man was affecting the global climate, with carbon dioxide seeming to be the key driver.

Far from considering this a bad thing, however, like Arrhenius before him, Callendar stated, “[It] may be said that the combustion of fossil fuel, whether it be peat from the surface or oil from 10,000 feet below, is likely to prove beneficial to mankind in several ways, besides the provision of heat and power. For instance the above mentioned small increases of mean temperature would be important at the northern margin of cultivation, and the growth of favourably situated plants is directly proportional to the carbon dioxide pressure… In any case the return of the deadly glaciers should be delayed indefinitely.”

Over the next couple decades of his life until his death in 1964, Callendar continued to publish papers and articles about the issue with little fanfare and significant resistance from those scientists who were reading his work.

As to why no one would accept what the data was saying, Callendar had his own ideas on that too, which proved to be every bit as accurate among climate change skeptics today as then. He postulated:

a. The idea of a single (easily explained) factor causing world wide climatic change seems impossible to those familiar with the complexity of the forces on which any and every climate depends. b. The idea that man’s actions could influence so vast a complex [system] is very repugnant to some. c. The meteorological authorities of the past have pronounced against it, mainly on the basis of faulty observations of water vapour absorption, but also because they had not studied the problem to anything like the extent required to pronounce on it. d. Last but not the least. They did not think of it themselves!

He would later sum up, “How easy it is to criticise and how difficult to produce constructive theories of climate change!”

All that said, while few were listening, few was not none. One such individual was Charles Keeling who, in 1958, was able to use far more accurate measurement equipment, partially of Keeling’s own design, to start gathering data at the Mauna Loa Observatory. The result was ground breaking and finally got scientists the world over paying attention. After all, these results, while more or less correlating with Callendar’s own data, came from a PhD and left little room for debate given the known accuracy of the instruments used.

In what would be called the Keeling Curve, the graph, besides accurately charting the fluctuation of atmospheric carbon dioxide levels throughout the seasons, showed a steady increase year over year that could be directly attributed to mankind’s activities.

From here, as the matter became more and more studied, the effects of added methane in the atmosphere also began to become just as concerning, primarily thanks to its potency as a greenhouse gas.

And while you might comedically think methane from the rising human population’s flatulence might be a culprit, it turns out, contrary to popular belief, only about 1/3 of humans have measurably significant amounts of methane in their rear valve’s gaseous expulsions, and even then only in certain circumstances. We’ll have much more on this fascinating phenomenon in the Bonus Facts shortly.

It turns out the real problem is the gas from another creature- cows, with livestock the largest source of methane gas emissions worldwide, contributing over 28% of those total emissions. (Wetlands, leaks from oil refineries and drills, and landfills also significantly contribute methane gas to the atmosphere.)

It’s commonly stated from this that cow farts are the burning problem, but this isn’t actually correct. According to researchers at New Zealand’s Crown Research Institute, AGResearch, up to 95 percent of the offending emissions come from the cow’s mouth rather than its behind, which is too bad for the darkly hilarious notion of cow farts someday significantly contributing to the demise of humanity should the extreme worst case ever happen… Sort of Bessy’s revenge for, you know, all the milking and slaughter which combines to give us delicious, mouthwatering cheeseburgers…

To put the effects of all this burping in perspective, as noted in the 2020 edition of the always interesting Bill & Melinda Gates Annual Letter, if the cattle the world over we use for our absolutely essential and God-given hamburgers and cheddar were a nation of their own and we calibrated the effect of the methane to an equivalent effect by a given amount of carbon dioxide, cattle would slot just behind #2 on the list of worst greenhouse gas emitters- the United States. (For those wondering, China is #1 here.)

In any event, going back to Keeling’s research, after he published his data, climate scientists and a handful of world leaders finally started paying attention. The problem was, in general, the wider public wasn’t really.

This all culminated in NASA’s James E. Hansen’s famous 1988 speech to the US Senate at the behest of Colorado Senator Tim Wirth. To make the presentation as effective as possible, it was purposefully planned during one of the hottest periods of the year in what was then one of the hottest summers on record. To drive the point home, Senator Wirth also had the air conditioning turned off during Hansen’s testimony. All combined with record temperatures, droughts, and abnormal weather patterns the world over, the public started listening too.

Naturally, with the public en masse now more aware of the problem and a bit panicky, efforts on both sides were almost immediately put in place to both lobby the governments of the world to help facilitate a solution, as well as on the other side, various major industries that could be negatively impacted in the immediate by such efforts, throwing a whole lot more money at convincing everyone there was no problem at all- everything is fine. Nothing to see here, move along. And, indeed, in their defense, the datasets and models of the era did allow for reasonable doubt on what the ultimate effect of all of this would be, something still debated today even with far better models and better idea of what temperature changes are likely to occur.

Of course, in the process of all of this, the matter became politicized- a sure fire way to ensure few among the public or politicians care about what the actual data says or the consensus of the experts in the field, and rather just whether the general idea was supported or not by the political party they, or in some cases their parents, ascribed to.

This all leads us to the hot mess we have today, with effectively a universal consensus among climate scientists the world over that climate change is happening, nearly as strong of a consensus that humans are the primary driver of that change, and a slightly lesser consensus on what the results of all of this will be- everything from an increase in temperatures over the next century sufficient to cause cascading and possibly unstoppable warming thanks to massive amounts of further greenhouse gasses being released as the polar regions melt, to more mild estimates of a mere couple degree increase. On the latter point, this is still a concern as it will result in obscene amounts of money needed to maintain coastal cities as well as resulting in millions in poorer regions of the world dying as a result, but at the least with humanity otherwise fine in the grand scheme of things so long as steps are taken in the interim to make sure the problem doesn’t get worse.

So what’s to be done?

On the simpler side of things, some have suggested dumping a few million tons of sulfur dioxide annually high in the atmosphere to more or less counter the effects of the additional carbon dioxide and methane added. At the cost of only in the billions for such a program, this is far less than is already being spent to counter the current effects of climate change on coastal cities. Of course, the downside of that are things like rather unhealthy air pollution and, once started, it could potentially be catastrophic to just stop the program all at once, depending on how long it had been going.

Thus, few find a method such as this a viable solution. It’s a blanket over the dried cat vomit on your couch. Sure, you can now use the couch as before without fixing anything and not get any vomit on you. But remove the blanket, and the vomit is still there. Nobody wants a vomit covered couch.

Others suggest a more environmentally friendly approach that actually adds to usable land on the planet- for instance covering the Sahara, among many other deserts, with forest. While this might seem an impossibility, it turns out this very thing has been done on a much smaller scale in places like the very doorstep of the Sahara, the region known as the Sahel. For example, after a series of droughts left tens of thousands dead, efforts were made in Burkina Faso to try to figure out a way to restore the soil, including via low tech, dirt cheap means. For example, one extremely effective method was placing long lines of small stones which allowed water to remain in the hard, cracked soil long enough for grass seeds to sprout. This, in turn, led to the area around this to retain more water and be cooled, which in turn spread until in only a handful of years fields where this was done were restored and could once again be farmed.

Additional efforts to accelerate the process included digging thousands of shallow holes and placing manure and tree seeds inside. This also all encouraged termites to setup shop, with these termites in turn digging tiny little trenches throughout the soil to help water get absorbed, instead of washed away. The combination of this resulted in the trees and subsequent vegetation thriving, with, for example, one man, Yacouba Sawadogo, managing to turn 50 acres of bare desert he owned into a giant private forest in relatively short order. Among other trees in his little forest included the jatropha curcas, with a mere 50 acres of these trees capable of offsetting the current carbon footprints of over 500 Americans per year.

On a much grander scale, using similar techniques, the populace of Niger managed to salvage a whopping 40,000 square miles of land in this way. For reference here, there are 15 states in the United States that are smaller than this area.

Of course, doing this in these regions bordering a desert is one thing; doing it in regions like the Sahara itself, and on that kind of scale (for reference the Sahara is 3.5 million square miles) is another.

And, while this is a significantly nicer blanket on the cat vomit, the underlying problem would still be there. In the end, solutions such as this are often seen as more appealing as they require no one to change the way we do anything and outsource the actual work to someone else…. Which, on that note, if anyone would like to volunteer to come clean up the dried cat vomit I currently have under a blanket on my couch, I’d really appreciate that…. It’s pretty gross…

As to fixing the underlying problem, it turns out that’s incredibly complex too, touching on basically every single facet of human life. For example, direct energy production to power our lives only accounts for about 25% of the greenhouse gas emissions humans are responsible for. So even if 100% of this type of energy we produce was switched to zero emission solutions, there’s still the big old elephant in the room of the other 75%, comprising such things as manufacturing of steel, cement, and plastics, maintenance of large buildings which are kind of essential to humans humaning. And you can take our cheeseburgers from our cold, dead hands.

There are no easy or cheap solutions, aside from somewhat undesirable ones like massively polluting the atmosphere in a cooling way, thereby simultaneously fixing one problem by creating new ones. It’s a complex problem that requires complex and very diverse and numerous solutions implemented across the globe and countless industries, all combining to simultaneously reduce additional greenhouse gas emissions, find ways to remove the rest, and at the same time help those most affected by the inevitable changes we can’t prevent in the meantime. As to this group, as Bill Gates aptly points out in the aforementioned Annual Letter, “The cruel irony is that the world’s poorest people, who contribute the least to climate change, will suffer the worst.”

In the end, while the problem is complex, humans are rather good at solving problems, especially when cheeseburgers are on the line. And in the last decade particularly, we’ve finally started admitting en masse that we have a cheeseburger, and climate change, problem, which is always the first step to finding a solution. Hope is not lost. As Gates sums up in the aforementioned annual letter,

Tackling climate change is going to demand historic levels of global cooperation, unprecedented amounts of innovation in nearly every sector of the economy, widespread deployment of today’s clean-energy solutions… and a concerted effort to work with the people who are most vulnerable to a warmer world… [This] is one of the most difficult challenges the world has ever taken on. But I believe we can avoid a climate catastrophe if we take steps now to reduce emissions and find ways to adapt to a warmer world.

If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes, Spotify, Google Play Music, Feed), as well as:

• Does the Ocean Continually Get Saltier?
• Can Bad Weather Cause Joints to Ache?
• What Determines “Partly Cloudy” vs. “Mostly Sunny”? (And Other Weather Terms Explained)
• Why Is Comfortable Air Temperature So Much Lower Than Body Temperature?
• The Terrifying Phenomenon of Spider Rain

Bonus Fact:

Going back to human methane in our rear expulsions, in one small study it was found that those that did have measurable amounts of methane only produced it when fed significant amounts of fiber. (The fiber free version of their farts was almost wholly made up of nitrogen for all subjects.) With the fiber version, the average fart only contained about 3.6% methane. The bulk of these individuals’ flatus was made up of hydrogen (51%) and nitrogen (30%).

Why only some people produce methane in their flatus isn’t entirely clear, though at least in part this has to do with what microbes call one’s intestines home. So far, only three microbes have been identified as methane producers (methanogens) in humans: Methaniobrevibacter smithii, Methanospaera stadmagnae and Methannobrevibacter oralis.

Scientists have identified a few factors in predicting if a person is a methane producer, and one of the most important of these appears to be where you live (although it’s not clear if genetics plays a role as well in some way). For example, while 77% of Nigerians and 87% of South Africans produce methane, only 34% of Norwegians and 35% of those who live in and around Minneapolis do so. In addition, adult women are more likely to produce measurable amounts of methane in their farts, and young children are less so. Finally, if both your parents produce methane, then there is a greater likelihood that you will, too, with one study indicating as high as a 95% chance that the spawn of two methane producers will also produce methane.