The argument generally is that warming temperatures cause rising CO2. This in turn is a fact not disputed by climate scientists, only that it is not sufficient to explain the current rise in CO2.
[1] A pro-AGW debunking of the common argument https://skepticalscience.com/co2-lags-temperature.htm
But it's a pretty simple equation. We know the approximate mass of the atmosphere, and the number of molecules per weight. We know how many molecules are in a unit mass of CO2.
Thus we should be able to calculate out "how many gigatons of CO2 are necessary to increase atmospheric CO2 by 1ppm", and then given measurements of actual CO2 increases, how much CO2 is necessary to increase atmospheric levels by the amounts seen.
If the amount of CO2 required to yield the observed increase is greater than annual human emissions, then that's a strong signal that CO2 increase is NOT anthropogenic and something else is going on. If it's less, then that is a strong signal that humans are the primary culprit.
Anyway, I did out all the math and it takes about 8.8 gigatons to increase atmospheric levels by 1ppm, and we're netting an increase of about 17gt into the atmosphere per year, for an increase of ~2ppm annually. So it's pretty clear that this is anthropogenic.
If anyone wants to check my math I wrote it all up here [0]. Numbers are a couple years old at this point but the conclusion still stands.
All are patently bullshit, of course.
It seems like the opposite to me, it’s a no-brainer that predicting what will happen to an immensely complex system, and making all these assumptions about what will occur 50-100 years from now is going to be hotly debated.
a casino can't predict the next 14 blackjack cards, but somehow it can predict the profit over the next 365 days (millions of blackjack cards)
just sayin.
What's impressive is that some people are so invested in not understanding climate that they reject the notion that larger trends can be bloody obvious before anyone can predict day-to-day variances. (Again, a basic principle that our stone tools ancestors figured out.)
A poor analogy is that you can’t predict where an atom is located and its speed due to quantum, yet when you average over a bunch of atoms you some pretty useful bounds on the shape of the problem.
Also, we already have plenty of data to evaluate the models - climate models are underpredicting the consequences (ie things are hotter and more volatile than climate models predicted). This indicates the models are conservative about the predictions in the wrong direction (you want to be predicting 20% worse than reality than 20% better because of it impacts planning). The reason they’re likely wrong is that we don’t have a full accounting of the ways in which human activity causes warming.
Obviously, meteorology doesn't work over a 50-100 years time frame -- "What's the temperature on January 20th 2064 and 9PM" is an impossible question to answer. But climatologists are not attempting to answer the same question as meteorologists. They're studying a much easier variable to predict, which is averages of phenomena, where all the short-term complicated meteorological noise cancels itself out due to the law of large numbers.
What we can do is predict the arc of motion of the centre of gravity .. that's climate.
It's a no-brainer that anybody who confuses the two and hasn't put in the work to raise their understanding to intermediate axis instability is below the bar for admission to grown up climate modelling discussions.
It should also be noted that the type of C in CO2 matters:
> In addition, only fossil fuels are consistent with the isotopic fingerprint of the carbon in today’s atmosphere. Different kinds of carbon-containing material have different relative amounts of “light” carbon-12, “heavy” carbon-13, and radioactive carbon-14. Plant matter is enriched in carbon-12, because its lighter weight is more readily used by plants during photosynthesis. Volcanic emissions are enriched in carbon-13. The ratio of carbon-13 to carbon-12 in the atmosphere and the ocean are roughly the same. Since carbon-14 is radioactive, it decays predictably over time. Young organic matter has more carbon-14 than older organic matter, and fossil fuels have no measurable carbon-14 at all.
> As carbon dioxide concentrations in the atmosphere have risen over the past century or more, the ratio of carbon-13 to carbon-12 has fallen, which means that the source of the extra carbon dioxide must be enriched in "light" carbon-12. Meanwhile, the relative amount of carbon-14—radioactive carbon—has declined. The record of carbon-14 in the atmosphere is complicated by nuclear bomb testing after 1950, which doubled the amount of radioactive carbon in the atmosphere. After the nuclear test ban treaty in 1963, the excess atmospheric carbon-14 began to decline as it dispersed into the oceans and the land biosphere.
* https://www.climate.gov/news-features/climate-qa/how-do-we-k...
> In this “Grand Challenges” paper, we review how the carbon isotopic composition of atmospheric CO2 has changed since the Industrial Revolution due to human activities and their influence on the natural carbon cycle, and we provide new estimates of possible future changes for a range of scenarios. Emissions of CO2 from fossil fuel combustion and land use change reduce the ratio of 13C/12C in atmospheric CO2 (δ13CO2). This is because 12C is preferentially assimilated during photosynthesis and δ13C in plant-derived carbon in terrestrial ecosystems and fossil fuels is lower than atmospheric δ13CO2. Emissions of CO2 from fossil fuel combustion also reduce the ratio of 14C/C in atmospheric CO2 (Δ14CO2) because 14C is absent in million-year-old fossil fuels, which have been stored for much longer than the radioactive decay time of 14C.
* https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...
They're not "skeptics". They're not even deniers. They're just liars.
There is no universe in which you can dig vast amounts of carbon, burn it, and not have things warm up. There are lots of hard questions but the fundamental fact that the globe has to warm is an unavoidable conclusion.
If you’ve ever owned a Fish Tank or taken High School Chemistry, you’d realize that even in the most simple environments things don’t always add up in a way that seems intuitive.