Guest Post by Willis Eschenbach
For the usual totally obscure reasons, I got to thinking about the increase in atmospheric CO2. I thought I’d compare it with population growth. Here’s that graph.
Figure 1. Atmospheric CO2 levels, and population growth, 1800 – 2020
When I looked at that graph, I noticed that the CO2 rose in general agreement with the population growth, but with a delay. Now, this made perfect sense to me. The population increases when a baby is born … but the baby doesn’t get involved in CO2-producing activities until the baby is an adult.
So I decided to see if I could use the standard formula for lagging and resizing that I used in my recent post about CO2, “Feeling The Bern“, to see if the CO2 levels could be emulated using just the population growth. Here’s the result of that calculation.
Figure 2. Atmospheric CO2 levels as calculated as a lagged and resized version of the population growth.
There are a few interesting points about this result. First, the fit is remarkably good. The residual standard error, which is the average difference between the calculated value and the actual CO2 level, is only one ppmv. That’s about a third of one percent error … very small.
Next, the half-life of the calculation is 30 years, a reasonable value for a child growing up and becoming involved in CO2-producing activities.
Next, over the last 170 years, there’s been no change in lambda, the amount of atmospheric CO2 increase per each additional billion people …
Most curious.
Having seen all of that, I got to thinking about the future. Here’s the UN population projection. They say that the population is likely to peak at around 11 billion people in the year 2100.
Figure 3. UN population projection to 2100.
So … assuming the population stays level at the 2100 level until 2200, and other things remain constant, two assumptions that are rarely true … here’s the CO2 projection out to the year 2200.
Figure 4. CO2 projection to 2200, using the method of Figure 2 with the same tau and lambda values.
And to complete the circle, here are temperature projections based on that estimate of future CO2 changes.
Figure 5. Past and future temperature anomalies based on the CO2 projections in Figure 4. Please be clear that I do not think that global average surface temperature is a function of CO2 levels, so this is done purely as a theoretical exercise.
And at the end of all of that, I’m reminded of Mark Twain’s comment regarding the length of the Mississippi River.
The Mississippi between Cairo and New Orleans was twelve hundred and fifteen miles long one hundred and seventy-six years ago. Its length is only nine hundred and seventy-three miles at present.
In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod.
And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen.
There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
Now, back to pressure-washing …
w.
Como De Costumbre: I can defend what I write. I choose my own words very carefully, and I’m often asked and always prepared to defend them. However, I can’t defend someone else’s interpretation of my words … so please, when you comment, quote the exact words you are referring to.
Please don’t tell the Green Folks – since CO2 so closely tracks the population, and CO2 is evil, they’ll want to outlaw population growth.
Certainly need to stop any greentards from reproducing.
Time to classify humans as a pollutant then. The curves match.
The Club of Rome and The Optimum Trust got there before you
The ultimate cause of all environmental problems, from the human perspective, is always humans one way or another. So, every environmental problem correlates with the total population of the world — virtually by definition. Thus, a common solution to almost all environmental problems is fewer people. So, Willis’ observation of the close correlation of CO2 concentration with total population is unsurprising and really pretty much intuitively obvious.
By the way, humans are part of nature. Anything attributed to human activities is natural by definition. Whether or not anything is due to humans, beneficial to humans or harmful to other species is another story
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Wow – that puts a new perspective on reducing CO2.
According to some estimates the covid19 pandemic will bring “peak humans” earlier by a couple of decades, and with nearly a billion less people. It could be sooner than we thought.
Seeing as we’re on Mark Twain, I’ll leave a little of Twain’s tale of Markiss. Some climate scientists and certainly the media might pay it some regard.
Almost from the very beginning, I regarded that man as a liar.
The line of points represents an interval of years. At the end of which time the opinion hazarded in that last sentence came to be gratifyingly and remarkably endorsed, and by wholly disinterested persons. The man Markiss was found one morning hanging to a beam of his own bedroom (the doors and windows securely fastened on the inside), dead; and on his breast was pinned a paper in his own handwriting begging his friends to suspect no innocent person of having any thing to do with his death, for that it was the work of his own hands entirely. Yet the jury brought in the astounding verdict that deceased came to his death “by the hands of some person or persons unknown!” They explained that the perfectly undeviating consistency of Markiss’s character for thirty years towered aloft as colossal and indestructible testimony, that whatever statement he chose to make was entitled to instant and unquestioning acceptance as a lie. And they furthermore stated their belief that he was not dead, and instanced the strong circumstantial evidence of his own word that he was dead–and beseeched the coroner to delay the funeral as long as possible, which was done. And so in the tropical climate of Lahaina the coffin stood open for seven days, and then even the loyal jury gave him up. But they sat on him again, and changed their verdict to “suicide induced by mental aberration”–because, said they, with penetration, “he said he was dead, and he was dead; and would he have told the truth if he had been in his right mind? No, sir.”
I noticed the interesting correlation between the Keeling curve and the human population growth curve about 20 years ago. Knowing that in a warming world it is inevitable that atmospheric CO2 will increase (Henry’s Law). Also with the industrial revolution and the explosion in human knowledge, heath improvements, improved agricultural practices etc one would expect increases in human population. What is a real surprise is the strength of the ongoing correlation.
I just love the way you think Willis, this was entertaining and funny. Made my day for sure, HAHAHA
Actually, IIRC, the IPCC also estimated in one of their reviews that both CO2 and temperature rises would stop/peak at around 2105. They also said that peak population was a major reason for that.
But the output of CO2 is not even per head of population… some countries output much more than others.
True … and race car drivers emit more CO2 than people in wheelchairs. Not sure what your point is here …
w.
Griff, I’m happily a resident of the former. If you aren’t happy with your profligate Western lifestyle, move.
Some say “demographics is destiny”
What say y’all about this:
“The global population is expected to grow by about 3.1 billion people between 2020 and 2100. More than half of this increase is projected to come from Nigeria, the Democratic Republic of the Congo, Tanzania, Ethiopia and Angola, along with one non-African country (Pakistan). Five African countries are projected to be in the world’s top 10 countries by population by 2100.”
World population growth is expected to nearly stop by 2100 | Pew Research Center
One estimate for Nigeria in 2100 is 732,941,595. [I think that last 595 is questionable!]
Another “expert” study claims the generally accepted forecast for the world is much too high, perhaps 2 B. We’ll just have to wait and see.
Did Prof Murry Salby do a similar analysis ?