Angliss's claim was that a "barely measurable" 0.001°C temperature increase in the ocean "could drive a massive spike in global air temperature" (1°C).
1/5. Stoichastich wrote, "He says quite clearly that the hothouse is warm because the glass absorbs dark rays from the ground (IR), which is clearly not why the hothouse is hot."
That's not what Arrhenius wrote. This is the paper:
This is the excerpt to which I think you must be referring:
"Fourier maintained that the atmosphere acts like the glass of a hot-house, because it lets through the light-rays of the Sun, but retains the dark-rays from the ground."
You've mistaken his meaning. In the first place, Arrhenius was summarizing what another scientist said. In the second place, the word "it" clearly refers back to "the atmosphere," not to the hot-house, as you've apparently supposed.
The main way that greenhouses retain heat is by preventing convective and evaporative cooling. That's why greenhouses made of plastic which is transparent to LW IR work just fine. (Glass greenhouses do get a small amount of additional warming effect by blocking outgoing LW IR.)iopscience.iop.org/article/10.108…
2/5. Stoichastich asked, "Where has anyone said that [Arrhenius] did use that term?"
You retweeted Dale Cloudman pointing out that "the greenhouse effect is a misnomer," in your tweet saying that Arrhenius' paper was "fundamentally flawed." So I thought that's what you meant.
3/5. Stoichastich asked, "Estimating it sounds interesting, but has it ever been measured?"
There've been some attempts both to calculate and to measure the "radiative forcing." I summarize them here:
1/7》GCP emission data shows 185.58 ppmv of fossil carbon emissions from 1959-2021 (plus a poorly constrained amt of non-fossil "land use change emissions"). Only about 5.56 ppmv (3%) was CO2 released from limestone [CaCO3] as it's baked to make cement.
@Piyush__Tank @JessePeltan 2/7》It's estimated that, on average, as concrete weathers it absorbs roughly half as much CO2 as was released from the limestone when it was made. That halves the 3% (5.56 ppmv) figure to 1.5%. The process is akin to natural rock weathering: sealevel.info/feedbacks.html…
3/7》It's often claimed that cement manufacturing causes "up to 8%" of anthropogenic CO2 emissions, but that figure includes estimated emissions from the fossil fuels burned to heat the kilns, typically accounting about half the total (though it varies according to how the kilns are fired). cfdflowengineering.com/cfd-modeling-o…
1/5. Willard, why do you ask questions that were answered at links I just gave you—that you refused to read?
I linked to a 7-part tweetstorm about the discredited Shakun/Marcott/Pages2K/Hagelaars "wheelchair" graph, which goes back 22K years. It completely erased D-O event #1, every last trace of it.
2/5. That wheelchair graph also erased all but ¼℃ of D-O event #0, a/k/a the Younger Dryas termination, a/k/a the start of the Holocene.
3/5. It also shows the middle of the Dark Ages Cold Period as slightly warmer than the middle of the Medieval Warm Period.
1/6. From measurements of downwelling LW IR, 342 W/m² is a reasonable, approximate estimate of downwelling LW IR radiation averaged over the entire surface of the Earth.
It's essentially identical to MacCracken's 1985 estimate (which he called "only an approximation"):
(Note: the numbers are percentages.)
The quoted text excerpt is:
“The fluxes of energy within the atmosphere-surface system can be illustrated using an energy balance diagram. Although many measurements have been made at the surface and from satellites, there are still uncertainties of 10-20% in the values of some of the fluxes because of the difficulty of making representative global measurements. In some cases model calculations have been used to generate estimates. The values shown in the diagram in Figure 1.2 are derived from consideration of energy balances prepared by Gates (1979), Liou (1980), and MacCracken (1984), and are only an approximation.”
Source:
M. C. MacCracken and F. M. Luther (Ed.), "Projecting the Climatic Effects of Increasing Carbon Dioxide," United States Department of Energy, DOE/ER 0237, Dec. 1985.
Note that the main source of uncertainty is not that we cannot measure downwelling LW IR. Rather, it is "the difficulty of making representative global measurements." Actual downwelling LW IR fluxes vary wildly with time and location, so finding an accurate global average is problematic, to put it mildly.sealevel.info/MacCracken1985… researchgate.net/profile/Michae…
3/6. Here's the NCA4 version (with my notes about the "radiative imbalance" added). They show downwelling LW IR = 338 to 348 W/m², with a best estimate of 342: sealevel.info/NCA4_global_en…