The FIRSTS: Increase in CO2 levels in the atmosphere results in global warming (1896)

Few people seem to know that although global warming and climate change are hotly debated topics right now (at least on the left side of the Atlantic) the effect of CO2 levels on the planet’s surface temperature was investigated and calculated more than a century ago. CO2 is one of the greenhouse gases responsible for the greenhouse effect, which was discovered by Joseph Fourier in 1824 (the effect, that is).

Let’s start with a terminology clarification. Whereas the term ‘global warming’ was coined by Wallace S. Broecker in 1975, the term ‘climate change’ underwent a more fluidic transformation in the ’70s from ‘inadvertent climate modification’ to ‘climatic change’ to a more consistent use of ‘climate change’ by Jule Charney in 1979, according to NASA. The same source tells us:

“Global warming refers to surface temperature increases, while climate change includes global warming and everything else that increasing greenhouse gas amounts will affect”.

But before NASA there was one Svante August Arrhenius (1859–1927). Dr. Arrhenius was a Swedish physical chemist who received the Nobel Prize in 1903 for uncovering the role of ions in how electrical current is conducted in chemical solutions.

S.A. Arrhenius was the first to quantify the variations of our planet’s surface temperature as a direct result of the amount of CO2 (which he calls carbonic acid, long story) present in the atmosphere. For those – admittedly few – nitpickers that say his views on the greenhouse effect were somewhat simplistic and his calculations were incorrect I’d say cut him a break: he didn’t have the incredible amount of data provided by the satellites or computers, nor the work of thousands of scientists over a century to back him up. Which they do. Kind of. Well, the idea, anyway, not the math. Well, some of the math. Let me explain.

First, let me tell you that I haven’t managed to pass past page 3 of the 39 pages of creative mathematics, densely packed tables, parameter assignments, and convoluted assumptions of Arrhenius (1896). Luckily, I convinced a spectroscopist to take a crack at the original paper since there is a lot of spectroscopy in it and then enlighten me.

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The photo was taken in 1887 and shows (standing, from the left): Walther Nernst (Nobel in Chemistry), Heinrich Streintz, Svante Arrhenius, Richard Hiecke; (sitting, from the left): Eduard Aulinger, Albert von Ettingshausen, Ludwig Boltzmann, Ignaz Klemenčič, Victor Hausmanninger. Source: Universität Graz. License: PD via Wikimedia Commons.

Second, despite his many accomplishments, including being credited with laying the foundations of a new field (physical chemistry), Arrhenius was first and foremost a mathematician. So he employed a lot of tedious mathematics (by hand!) together with some hefty guessing along with what was known at the time about Earth’s infrared radiation, solar radiation, water vapor and CO2 absorption, temperature of the Moon,  greenhouse effect, and some uncalibrated spectra taken by his predecessors to figure out if “the mean temperature of the ground [was] in any way influenced by the presence of the heat-absorbing gases in the atmosphere” (p. 237). Why was he interested in this? We find out only at page 267 after a lot of aforesaid dreary mathematics where he finally shares this with us:

“I certainly not have undertaken these tedious calculations if an extraordinary interest had not been connected with them. In the Physical Society of Stockholm there have been occasionally very lively discussions on the probable causes of the Ice Age”.

So Arrhenius was interested to find out if the fluctuations of CO2 levels could have caused the Ice Ages. And yes, he thinks that could have happened. I don’t know enough about climate science to tell you if this particular conclusion of his is correct today. But what he managed to accomplish though was to provide for the first time a way to mathematically calculate the amount of rise in temperature due the rise of CO2 levels. In other words, he found a direct relationship between the variations of CO2 and temperature. Today, it turns out that his math was incorrect because he left out some other variables that influence the global temperature that were discovered and/or understood later (like the thickness of the atmosphere, the rate of ocean absorption  of CO2 and others which I won’t pretend I understand). Nevertheless, Arrhenius was the first to point out to the following relationship, which, by and large, is still relevant today:

“Thus if the quantity of carbonic acid increased in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression” (p. 267).

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P.S. Technically, Joseph Fourier should be credited with the discovery of global warming by increasing the levels of greenhouse gases in the atmosphere in 1824, but Arrhenius quantified it so I credited him. Feel fee to debate :).

REFERENCE: Arrhenius, S. (April 1896). XXXI. On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science (Fifth Series), 49 (251): 237-276. General Reference P.P.1433. doi: http://dx.doi.org/10.1080/14786449608620846. FREE FULLTEXT PDF

By Neuronicus, 24 June 2017

The Atlantic cod is driven to extinction by overfishing and global warming

Say bye-bye to this tasty beauty. Atlantic cod (Gadus morhua) picture by Hans Hillewaert (CC BY-SA 4.0)
Say bye-bye to this tasty beauty: the Atlantic cod (Gadus morhua). Picture by Hans Hillewaert released under CC BY-SA 4.0 license.

Pershing et al. (2015) analyzed a lot data from 1982-2013 about the Gulf of Maine temperatures, cod population metrics, and global warming indices. Global warming has hit the Gulf of Maine harder than anywhere else on the planet, with temperatures rising much faster than the rest of the global ocean during the last decade (about 0.23 Cº per YEAR). As a direct consequence, the cod population has declined very rapidly in the last two decades: “The most recent assessment found that the spawning biomass in this stock is now less than 3,000 mt, only 4% of the spawning stock biomass that gives the maximum sustainable yield” (p. 2)., which means, to my non-marine biologist understanding, that 96% of the little fishes required to make a sustainable pool for fishing are dead.

The authors go further and analyze predator behavior, zooplankton availability (which has declined due to… you are correct, that pesky global warming again) coupled with the recent heat waves and they say that, despite the horribly rapid decline in the population, the cod would have bounced back if it wasn’t for overfishing. That’s right, folks! Is not enough that global warming (which is also man-made, the nay-sayers are deluded, period) has jeopardized this species, but we made sure is on the brink of extinction by overfishing it. The quotas set for the fishing industry failed to take into the account the global warming effect of the population, setting fishing quotas for a steady-state system, which obviously the Gulf of Maine is not.

You may say, “All righty, then. Let’s fish some less cod until it bounces back. Some major fisheries will go bankrupt, but, hey, we’re saving the fishes so we can eat them later. Easy-peasy”. Not so fast. The gravity of the situation is further accentuated by the very doom and gloom predictions of a basic population dynamics model that the authors publish in the form of Fig. 3 of the paper. The cod population may bounce back, if we stop the fishing now COMPLETELY. Not a little bit, not a few here and there, not the slow and the weak, but ALL fishing needs to stop now if we want to rebuild the cod stock population. And you don’t get to say “damn the cod, I don’t eat it anyway’, because you don’t know what else might be driven to extinction by the disappearance of the cod.

I am not exaggerating here with metaphors. Read the paper and take a look at the scientists’ simulations and predictions yourselves.

Reference: Pershing AJ, Alexander MA, Hernandez CM, Kerr LA, Le Bris A, Mills KE, Nye JA, Record NR, Scannell HA, Scott JD, Sherwood GD, & Thomas AC (Epub 29 October 2015). Slow adaptation in the face of rapid warming leads to collapse of the Gulf of Maine cod fishery. Science, DOI: 10.1126/science.aac9819. Article | FREE FULLTEXT PDF

By Neuronicus, 30 October 2015