A staple complaint of the climate sceptic, that it’s impossible to determine the impact of historical volcanic eruptions on the climate, is a step closer to being spiked, courtesy of work at the University of Copenhagen. The university’s Matthew Johnson, an associate professor in the Department of Chemistry, has published work …
Sulphur aerosols are a classic area for disagreement. If you can't say which eruptions did have an effect you can simply eyeball the size of the volcano and state every eruption must have had an effect.
Thumbs up going out and working out how to stop the argument rather than prolong it.
The usual caveat that climate modellers take this on board.
Step-wise refinement. It's how science works.
The chances of it discriminating accurately between 535 and 541
are pretty slim.
And facts are irrelevant to some sceptics anyway so it will have little effect on the 'argument' - except the leading or trailing SO2 distraction...
Re: The chances of it discriminating accurately between 535 and 541
The 535 event is intriguing because it is even larger in magnitude and area than the 1816 'Year without a summer' caused by Mount Tambora. Reports of incredibly cold winters, crop failure and dry sulfurous fogs extend from Northern Europe to China, the Middle East and South America.
A volcano is the most likely cause, but one at high latitudes (such as those in Iceland) would be unlikely to affect the Southern Hemisphere, so efforts have previously concentrated on suitably monstrous mountains in the tropics including Rabaul (New Guinea (erupting right now)) and Lake Ilopango (El Salvador). To cause the drop in temperatures it would have to be a VEI 7 eruption - think ten Pinatubos or one-thousand Eyjafjallajökulls. Last year there was also a suggestion it might have been caused by a devastating, eruption of Krakatau previously dated to 416 from Javanese historical records. There is however little geological evidence at Krakatau of an eruption in the mid-6th Century.
Going back to Iceland, if they can find a sulfur spike in a core from the Greenland cap (which can be pretty easily dated to individual years) which has a sulfur isotope imbalance they can ascribe it to a large event in Iceland at a fixed time. Most Icelandic eruptions don't inject much sulfur into the stratosphere, so for the isotopes to be buggered it would have to be a big one along the lines of the VEI 6 Eldgjá and Laki eruptions of 934 and 1783 respectively - neither of which did much good to the environment.
"A staple complaint of the climate sceptic, that it’s impossible to determine the impact of historical volcanic eruptions on the climate"
Chirgwin's assertion, like most of his assertions, is scientifically illiterate.
Volcanic eruptions are one of the easier factors to assess and model, because the effect is dramatic and short-lived. We simply compare the temperature record with periods of low volcanic activity.
That wasn't hard was it?
Not only does Chirgwin not understand the climate, he's never met a sceptic.
Re: huh?? indeed
I'm guessing he's just met his first.
Re: huh?? indeed
Dr Stephen Jones, considering about 90% of your comments allege some form of mental deficiency on the part of anyone that doesn't deny global warming (when you're not banging on about Guardian readers, Malthusians, Richard Dawkins and people that aren't "real scientists", presumably because they haven't awarded their login a doctorate) I'm sure Mr Chirgwin is familiar with sceptics.
In fact, after reading all 135 of your comments, you don't seem to have a nice word to say about anyone. How sad.
Re: huh?? indeed
Here's one. Scientific training demands scepticism. Do you assess the science for yourself or do you let others translate it for you? If it's the latter, then you're in a vulnerable position.
Re: huh?? indeed
"We simply compare the temperature record with periods of low volcanic activity."
And you have some kind of volcano log with a data/eruption list you can refer to that allows you to do this?
I did not know such an independent log existed.
Where can this volcano activity log be found?
Why does it have to "spike" the criticisms of skeptics?
Isn't it just as likely to "spike" the absurdities of the Warmist cabal?
I mean, at least if it is real science and not just more warmist propaganda?
Re: Why does it have to "spike" the criticisms of skeptics?
Changeist would be a better term of abuse than warmist. As more evidence is gathered and understood it looks more like some places will get hotter and others colder. Some will get wetter and others dryer. Look at the paradox of warming changing the north Alantic current resulting in a colder climate for RoI and the UK.
"reacts with sunlight to produce a different isotopic signature"
so since when has sunlight produced nuclear mutations?
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