Re: more scary stuff
 

The “Volcano Question” is a good one. Much of the information floating about seems heavily influenced by personal bias or by who happens to be funding the study. I suggest two documents as helpful:

http://plaza.ufl.edu/airwess/
http://climate.envsci.rutgers.edu/pd...ThePlanet2.pdf

They have a spin, but are informative. The gist of these and other sources, plus my geology classes and industry experience, seems to be that we live on a planet that is dynamically changing and totally indifferent to our existence and mostly unaffected by our efforts. The biological component of the planet scrambles and reacts to the planet’s physical changes by either adapting or dying. It would seem that volcanism is responsible for creating our atmosphere and has changed the atmosphere’s composition over time. That change is ongoing and is still underway. Our admittedly shallow database of measurements seem to indicate that climatic changes induced by a single eruption from carbon dioxide and ash are significant but relatively short termed (2-6 years, depending on the source). The emissions of sulphur compounds and other materials are less well understood. Apparently the gross emissions of sulphur dioxide from eruptions are only 15% of man-made emissions. That number is shaky and there are natural sources other than explosive eruptions. Perhaps more important is where the injection of the SO2 occurs. Much of the volcanically generated SO2 occurs at high enough altitudes to have an impact out of proportion to its volume. Also, I know that in drilling for oil and gas we use layers of ash at different depths as markers to aid in telling where we are relative to certain target zones. Some of these as layers are local, covering only a few states. At least one is found world-wide. In the end, our climate and weather are driven by that overwhelming engine of heat, the sun. That is as true on Venus, with a sulphurous atmosphere, as it is on Earth or Jupiter. The composition of that atmosphere is a product of the planet itself.

Anyway, I think that our activities have some impact but that over time they are overwhelmed by natural processes (unless we do something really silly; nuclear war, anyone? Even that will disappear over geologic time). Perhaps even more interesting is the clustering of major volcanic and meteor activity at the great extinction events in history, particularly the Paleozoic-Mesozoic and Mesozoic-Cenozoic boundaries. Most people don’t realize that 60% of all known species became extinct at the Paleozoic-Mesozoic boundary. A company called Pan Terra produces a fabulous wall chart titled “A Correlated History of the Earth” detailing the evolution of animal and plant life, plate tectonics, and volcanic and meteor activity.

Another comforting thought: the Galactic Drift theory has us due for a meteor/comet strike and another massive die-off….

Edit for grammar.

[ February 13, 2004, 18:45: Message edited by: solops ]

Re: more scary stuff
 

<font size="2" face="sans-serif, arial, verdana">i'm undecided on this, but i don't see how we'd have instruments to measure holes in the ozone more than a century ago. unless they leave a mark somewhere; tree rings, geology...

Re: more scary stuff
 

<font size="2" face="sans-serif, arial, verdana">i'm undecided on this, but i don't see how we'd have instruments to measure holes in the ozone more than a century ago. unless they leave a mark somewhere; tree rings, geology... </font><hr /></blockquote><font size="2" face="sans-serif, arial, verdana">I'm not sure either, though I have read work on paleo-atmospheres. I recall the evidence as coming from rock and water samples from cores. We also learn of paleo-environments from things like crude oil:

"Crude Oils Provide Molecular and Isotopic Clues about OAEs
John Zumberge, GeoMark Research, Ltd, and Roger Summons, MIT"

http://aapg.confex.com/aapg/da2004/t...aper_86525.htm

[ February 13, 2004, 20:17: Message edited by: solops ]

Re: more scary stuff
 

Core samples from glaciers in Greenland and Antartica. The gases caught in the ice enable researchers to measure the ratio of gases in the atmosphere.

Anyway - You are right natural effects will eventually overwhelm anything humans can do but that wasn't the issue.

The issue was that Fyron wrote - as it if were self-evident - that:

<font size="2" face="sans-serif, arial, verdana">Even your two links refute that myth.

[ February 13, 2004, 20:34: Message edited by: rextorres ]

Re: more scary stuff
 

<font size="2" face="sans-serif, arial, verdana">Which was an article lacking any form of reference, just making lots of unsupported bold assertions. Like most sources on the internet... What I linked to had information on how volocanos damage the ozone layer (other than that one link that just discussed what the Mt. Pinatabo volcano was). Unless you want to assert that NASA's data is flawed, of course.

<font size="2" face="sans-serif, arial, verdana">As did that EPA article.

<font size="2" face="sans-serif, arial, verdana">No. And the myth that we are solely responsible for destroying the ozone is not a well known fact just because it is a repeated statement either.

<font size="2" face="sans-serif, arial, verdana">Nothing I linked to started off in such a manner. But either way, most (all?) scientific essays begin with some well known facts. It is pretty hard to discuss complicated issues if you do not accept less complicated issues as fact. Unless you want to prove every single item used in your essay every time you write one, of course.

<font size="2" face="sans-serif, arial, verdana">This goes both ways, of course. I did not first make up my mind and then go searching for evidence, I read various forms of evidence and then made up my mind. You seem to be doing just what you are accusing me of.

<font size="2" face="sans-serif, arial, verdana">Don't presume to lecture me on the scientific method. Such in no way helps your arguement.

<font size="2" face="sans-serif, arial, verdana">And you know this how? Because you have made up your mind and are unwilling to look at other facts that contradict your belief?

<font size="2" face="sans-serif, arial, verdana">Please tell me where I ever said that? Volcanos have been damaging the ozone for countless millennia. The ozone layer has only been around for ~600 million years anyways. When the earth was much younger and had much more violent volcanos, there was no ozone layer. Free-floating oxygen in relatively large quantities is a by-product of the development of anaerobic bacteria which produced it in photosynthetic processes. The ozone layer is constantly replenished due to UV ray interactions with free floating O2 molecules. reference

Re: more scary stuff
 

Apparently there are only measurements back to 1956. Here is a link that the EPA's website links to.

http://www.faqs.org/faqs/ozone-depletion/antarctic/

It seems to answer a lot of questions.

Re: more scary stuff
 

<font size="2" face="sans-serif, arial, verdana">Drilling arctic ice and analysing the water frozen thousands of years ago reveals a lot about past climates. Really interesting.

Re: more scary stuff
 

*delete*

[ February 13, 2004, 21:02: Message edited by: Roanon ]

Re: more scary stuff
 

Any dogmatic assertion is unwarranted. For instance, this article make an interesting argument:

http://www.co2andclimate.org/climate...v3n16/hot1.htm

However, in just perusing down the lists of titles generated from a search one can readily see that there is a whole variety of positions and “proofs” to choose from. After reading a few rabidly anti-human articles and a few confident “the volcanos did it” articles, I can confidently assert that I don’t know and neither does anyone else. The evidence is inadequate. I BELIEVE, based on the data I have seen, that volcanos have in the past and still do cause at least variations in the ozone. I suspect that man does so as well. Certain theories can be put forward, based on the available data, both pro and con, but none are conclusive. I KNOW (as much as is humanly possible) from the facts recorded in the rock and ice of our planet that the sun, volcanos and outgassings from subterranean sources WILL change the atmosphere and climate over time. Our ability to do so has not been proven, but I know we can if we try. Time will tell.

Edit for dogmatism.

[ February 13, 2004, 23:09: Message edited by: solops ]

Re: more scary stuff
 

How come is it that anytime there is a debate with Fyron involved it degenerates to a debate of semantics.

The only person that made an unequivical statement was Fyron. (I'll repeat what he wrote for effect)

<font size="2" face="sans-serif, arial, verdana">What Fyron wrote seems unambiguous (even taken in the context that it was written) - at least to me.

Even Fyron's links don't make the assertions that Volcanoes cause the hole in ozone layer. All they suggest is that Volcanoes made the hole worse not that they were the cause of the hole.

If Fyron wants we can continue to argue the meaning of words, the sources of links, the politics of the posters or the appropriateness of the Posts. It certainly won't be a debate about Ozone depletion.

[ February 13, 2004, 21:56: Message edited by: rextorres ]