[CasX]

Warning over increased UV exposure

http://onenews.nzoom.com/onenews_detail ... -7,00.html

The ozone hole over Antarctica is at near-record size, which may mean extreme levels of UV exposure over the summer.

NIWA scientist Stephen Wood says the hole is over 29 million square kilometres - almost four times the size of Australia.

Wood says the ozone depleted air is currently well contained over Antarctica but the timing of the break-up may have serious effects for New Zealand.

When the hole breaks-up, it disperses ozone-depleted air around the southern hemisphere.

If this coincides with the peak of summer, it can result in extreme levels of ultraviolet exposure.

[The American Lion]

I dont blame humans for this anyway. I just believe its a normal process of the Earth and the Sun is a little hotter. Dont be scared of a hole.

[Buck Williams]

I dont blame humans for this anyway. I just believe its a normal process of the Earth and the Sun is a little hotter. Dont be scared of a hole.

It is humans fault for the hole.

At any given time, ozone molecules are constantly formed and destroyed in the stratosphere. The total amount, however, remains relatively stable. The concentration of the ozone layer can be thought of as a stream's depth at a particular location. Although water is constantly flowing in and out, the depth remains constant.

While ozone concentrations vary naturally with sunspots, the seasons, and latitude, these processes are well understood and predictable. Scientists have established records spanning several decades that detail normal ozone levels during these natural cycles. Each natural reduction in ozone levels has been followed by a recovery. Recently, however, convincing scientific evidence has shown that the ozone shield is being depleted well beyond changes due to natural processes.

II. Ozone Depletion
For over 50 years, chlorofluorocarbons (CFCs) were thought of as miracle substances. They are stable, nonflammable, low in toxicity, and inexpensive to produce. Over time, CFCs found uses as refrigerants, solvents, foam blowing agents, and in other smaller applications. Other chlorine-containing compounds include methyl chloroform, a solvent, and carbon tetrachloride, an industrial chemical. Halons, extremely effective fire extinguishing agents, and methyl bromide, an effective produce and soil fumigant, contain bromine. All of these compounds have atmospheric lifetimes long enough to allow them to be transported by winds into the stratosphere. Because they release chlorine or bromine when they break down, they damage the protective ozone layer. The discussion of the ozone depletion process below focuses on CFCs, but the basic concepts apply to all of the ozone-depleting substances (ODS).

In the early 1970s, researchers began to investigate the effects of various chemicals on the ozone layer, particularly CFCs, which contain chlorine. They also examined the potential impacts of other chlorine sources. Chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere. Chlorine compounds from these sources readily combine with water and repeated measurements show that they rain out of the troposphere very quickly. In contrast, CFCs are very stable and do not dissolve in rain. Thus, there are no natural processes that remove the CFCs from the lower atmosphere. Over time, winds drive the CFCs into the stratosphere.

The CFCs are so stable that only exposure to strong UV radiation breaks them down. When that happens, the CFC molecule releases atomic chlorine. One chlorine atom can destroy over 100,000 ozone molecules. The net effect is to destroy ozone faster than it is naturally created. To return to the analogy comparing ozone levels to a stream's depth, CFCs act as a siphon, removing water faster than normal and reducing the depth of the stream.

Large fires and certain types of marine life produce one stable form of chlorine that does reach the stratosphere. However, numerous experiments have shown that CFCs and other widely-used chemicals produce roughly 84% of the chlorine in the stratosphere, while natural sources contribute only 16%.

Large volcanic eruptions can have an indirect effect on ozone levels. Although Mt. Pinatubo's 1991 eruption did not increase stratospheric chlorine concentrations, it did produce large amounts of tiny particles called aerosols (different from consumer products also known as aerosols). These aerosols increase chlorine's effectiveness at destroying ozone. The aerosols only increased depletion because of the presence of CFC - based chlorine. In effect, the aerosols increased the efficiency of the CFC siphon, lowering ozone levels even more than would have otherwise occurred. Unlike long-term ozone depletion, however, this effect is short-lived. The aerosols from Mt. Pinatubo have already disappeared, but satellite, ground-based, and balloon data still show ozone depletion occurring closer to the historic trend.

One example of ozone depletion is the annual ozone "hole" over Antarctica that has occurred during the Antarctic Spring since the early 1980s. Rather than being a literal hole through the layer, the ozone hole is a large area of the stratosphere with extremely low amounts of ozone. Ozone levels fall by over 60% during the worst years.

In addition, research has shown that ozone depletion occurs over the latitudes that include North America, Europe, Asia, and much of Africa, Australia, and South America. Over the U.S., ozone levels have fallen 5-10%, depending on the season. Thus, ozone depletion is a global issue and not just a problem at the South Pole.

Reductions in ozone levels will lead to higher levels of UVB reaching the Earth's surface. The sun's output of UVB does not change; rather, less ozone means less protection, and hence more UVB reaches the Earth. Studies have shown that in the Antarctic, the amount of UVB measured at the surface can double during the annual ozone hole. Another study confirmed the relationship between reduced ozone and increased UVB levels in Canada during the past several years.

Laboratory and epidemiological studies demonstrate that UVB causes nonmelanoma skin cancer and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts. All sunlight contains some UVB, even with normal ozone levels. It is always important to limit exposure to the sun. However, ozone depletion will increase the amount of UVB, which will then increase the risk of health effects. Furthermore, UVB harms some crops, plastics and other materials, and certain types of marine life.

For more information, see the Ozone Depletion Process page.

http://www.epa.gov/ozone/science/sc_fact.html

[The American Lion]

In the middle ages the weather was much hotter than today. I dont believe the Byzantine Empire had fossiel fuels at the time. Remember we just got out of the Ice Age too.

[Demosthenes]

Nonsense Nicolae, for every aricle like this you can find an article that proves humans are too insignificant to effect the planet as whole in this manner...

a fresh link that no one who believes we are responsible for global warming likes to see...

http://www.oism.org/pproject/s33p36.htm

[Yeddi]

Bahm what do you Northern Hemispherians care. We are the ones who have to deal with UV exposure, the hotter weather, our 7 year long drought, our water storage levels. YOu can sit there and say it's 'all natural' But it is the Aussies, the New Zealanders, the Chileans, the south africans who will have to deal with the weather

[CasX]

Unbelieveable, Americans, who along with other nations like China, are the major cause of these sorts of problems, sitting back and expousing rubbish. My sister is a scientist, this stuff is for real.

American anti-environmentalism will come back to bite you in the ass in time. But for now, it is other people who are paying the price.

[Freedom]

Funny how Demo gave you link packed full of facts and you reply with that...really thats funny...it matters little whether your sister is a Scientist...its scientists saying that its wrong...

[CasX]

Don't get me wrong. With regards to climate change, the effects of humans are minimal. And must be kept minimal. When refering to anti-environmentalism, it is a broad subject. There are all sorts of pollutions, and all sorts of natural environment loses.

[The American Lion]

Unbelieveable, Americans, who along with other nations like China, are the major cause of these sorts of problems, sitting back and expousing rubbish. My sister is a scientist, this stuff is for real.

American anti-environmentalism will come back to bite you in the ass in time. But for now, it is other people who are paying the price.

Then ask your sister this?

Why were the middle ages hotter than today even thought they werent burning Fossil Fuels?

Source:
http://www.telegraph.co.uk/news/main.jh ... clim06.xml

They also confirm claims that a Little Ice Age set in around 1300, during which the world cooled dramatically. Since 1900, the world has begun to warm up again - but has still to reach the balmy temperatures of the Middle Ages.

Here you go you might like this?

Trees are a major role in creating Smog
http://www.water.az.gov/NewsArchive/trees031703.htm

[CasX]

You do know that most of the Greenhouse effect is natural, don't you? If it wasn't we all be freezing to death.

Seriously, my sister has been working with a world-leading research institute on all these types of things. She knows more than you.

Environmentalism is important. And like I said, if the US keeps up its current policies, all will pay.

[The American Lion]

You do know that most of the Greenhouse effect is natural, don't you? If it wasn't we all be freezing to death.

Seriously, my sister has been working with a world-leading research institute on all these types of things. She knows more than you.

Environmentalism is important. And like I said, if the US keeps up its current policies, all will pay.

Well I dont believe my Truck is killing the Earth. When i get rid of my truck im getting an SUV. Because Im an American we all love big things. You can have all the Yugos.

"In a Yugo"

[smashthestate]

LOL! If it weren't for the greenhouse effect, we'd all be dead. The greenhouse effect is what makes the Earth habitable for life. I think you are more worried about the unnatural ozone depletion.

Also, it's not only the burning of fossil fuels that causes this. Cow farms, which release gigantic amounts of methane and other gasses into the atmosphere actually make a larger contribution to the ozone depletion than the burning of fossil fuel.

[Buck Williams]

True greenhouse gases do occur naturally... however do to increased fossil fuel usage there has been an increase in the amount of the gases, causeing warmer temperatures.

True cow farms do release alot of greenhouse gases also. But man is resposible for all the cow farms.

Bahm what do you Northern Hemispherians care. We are the ones who have to deal with UV exposure, the hotter weather, our 7 year long drought, our water storage levels. YOu can sit there and say it's 'all natural' But it is the Aussies, the New Zealanders, the Chileans, the south africans who will have to deal with the weather

About that..... I blame the republicans......

[Nox]

About that..... I blame the republicans......

Me too!

I also blame them for the killing off of the forests in Europe because of the pollution. My sister (who is not a scientist) once talked to an idiot who knew of a moron who had an imbecile for a sister whose boyfriends cousin once had the idea that there was a giant funnel cloud that went from the US, over the ocean, and dropped right down on central Europe. This funnel cloud sucked up all the US pollution and dumped it on Europe. The irony is ... the Republicans sneaked the legislation authorizing the research through the Democratic Congress in 1855. More on that later.

Nox
Nox

[Buck Williams]

Me too!

I also blame them for the killing off of the forests in Europe because of the pollution. My sister (who is not a scientist) once talked to an idiot who knew of a moron who had an imbecile for a sister whose boyfriends cousin once had the idea that there was a giant funnel cloud that went from the US, over the ocean, and dropped right down on central Europe. This funnel cloud sucked up all the US pollution and dumped it on Europe. The irony is ... the Republicans sneaked the legislation authorizing the research through the Democratic Congress in 1855. More on that later.

Nox
Nox

Nox, you must admit that protecting the enviroment is not the very high up the republican to-do list

[Demosthenes]

Ok, because Cas-X always has to be the voice of disent when I post let me post a disclaimer for the record so people will understand I don't profess to "kill the planet"

first off, when I reject wild claims of humans killing the planet I am referring to enviremental whackos. I mean the radial far leftists who have in the past tried to claim we were chopping down trees in the Amazon rain forest at some rediculous rate of 5 acres every second or some such nonsense; or claims that 10 species are going extinct every 5 seconds; or following Nox's logic that 5.5899321098 insects are squashed every .0000092385290 seconds, some of which might be beneficial to mankind if the moon turns red and skies bleed orange silicon rain.

That kind of nutty as a fruitcake il-logic is better laughed off than worried about. (incidentally the former president of the Sierra Club admitted on a Dennis Miller episode that the tree cutting thing was a lie, the rest is simply my creativity) Anyway, such "sky is falling" drivel is firstly purely politically driven. If scientists are able to convince their collective funding agencies that a problem exists BAM they receive funds and prolong their jobs, so it's in their best interests to create problems. Secondly such obviously farcial rhetoric only serves to demean and lesson the impact of true envirenmental issues.

I have grown very skeptical over the years in regards to radical envirenmentalism, as most of the time it's perpetuated by those with very big hearts, and quite a bit of compasson but carried out with little regard for common sense and logic. So it is in this vein that I often critisize envirenmental movements on what I would call a global scale.

Now on a localized scale I see different issues at play. It is pure folly to shit in your drinking water for instance. It is pure stupidity to pump toxic gases into a valley that has no real air circulation, so that this air sits in said valley and makes the air impure. So I'm not advocating being a total idiot with our resourses and our pollution output and neither are most conservatives, if any of you would bother to listen to them without preconceived notions arising from the liberals of the world.

In my experience their is no greater conservationist than a responsible hunter or fisherman or such. They are in touch with nature, understand the world around them better than any scientist in a lab reading toxicity reports and fully comprehend the delicate balance of nature. I know this topic isn't about hunting, but once again that is my experience. So I tend to weigh the opinions of those in the wild than of those in alab measuring the output of methane gas emanating from a cow's ass.

Cas- I am not denying there is a greenhouse effect. My point is that humans have nothing to do with, or so very little that we have more important things to worry about.

I will take your word that your sister is an intelligent scientist and believes in her work. However no matter what she tells me through you I'm not going to loose my common sense over the whole thing. The sky is not falling. There is no horrible price to be paid for CFC use other than those local effects I mentioned. The wanton belief in an unproven science like global warming is more akin to burning witches than say exploring the ocean for new marine life or calculating when a super nova might explode at some distant point in the future.

Comrade Nicolae:

Nox, you must admit that protecting the enviroment is not the very high up the republican to-do list

You're right but conservation is, and always has been. Which is much more founded in reality.

True cow farts do release alot of greenhouse gases also. But man is resposible for all the cow farms.

I'm sorry guys but have to reject this. Show me all the links you want but guess what? Animals have been farting for thousands of years. You might say "yeah but I mean cows, their brand is distinctly odorous" I say "Ok perhaps their are more cows now than their have ever been but cow farts can't be that different in compositon than say, Buffalo farts...or Wooly Mammoth farts, or Dinosaur farts if you want to go back 65- 250 some odd million years ago. You telling me that somehow cows are going to kill the planet with their farts??? When all these animals have been farting since before humans walked the earth? I don't think so. Sorry guys, "Scientists" used to say the worldwas flat too, but look what happend to that theory...

The earth has magical ways of healing itself in a very rapid manner. In fact most of the effects humans have on the earth are so short term as to be unworthy of even a footnote in the history of the planet. Short of a catostrophic disaster the earth clenses itself regularly and if it gets tired of the humans that really are smaller than the dust mites eating our flesh right now (in context) than I'm sure the earth will do something about it...and there's not a damn thing we can do about it...except maybe leave...

edit- ok because I know you guys are still convinced I'm the debil for wanting to kill you with my wanton burning of fossil fuels and refusal to accept even your best efforts here is a link for you: http://www.nas.nasa.gov/About/Education/Ozone/ozonelayer.html


Plus some excerts:

The effects of a large volcano on global weather are significant, which in turn can affect localized weather patterns such as the antarctic ozone hole. Many observations have linked the 1991 Mt. Pinatubo eruption to a 20% increase in the ozone hole that following spring[Solomon et al. 1993]) . The effects of a large volcanic eruption on total global ozone are more modest (less than 3%) and last no more than 2-3 years.

Sunspot cycle: ozone is created by solar UV radiation. The amount of UV radiation produced by the sun is not constant but varies by several percent in a rougly 11year cycle. This 11year cycle is related to magnetic changes within the sun which increase the solar UV output, and is heralded by an increase sunspots which appear on the surface of the sun. Comparisons of yearly ozone concentrations show a small 11 year variation in global ozone of about 2%. Episodes of unusual solar activity, solar storms and large solar flares, could certainly alter this value.

Guess what boys? This happens to be a big year in the world of solar flares, as I understand we are near the peek of this cycle of sunspots. We have been warned for months that satellite services could be disrupted in the near future and BIG SURPRISE Solar activity could potentially shut down the power in a major city due to the incrase in UV rays! (power outage on the east coast with no real explanation anyone?)I'm sorry we're just not as evil as most of you need us to be to feel guilty about yourselves or to just hate Americans that much more.

[Buck Williams]

Quote:
True cow farts do release alot of greenhouse gases also. But man is resposible for all the cow farms.


I'm sorry guys but have to reject this. Show me all the links you want but guess what? Animals have been farting for thousands of years. You might say "yeah but I mean cows, their brand is distinctly odorous" I say "Ok perhaps their are more cows now than their have ever been but cow farts can't be that different in compositon than say, Buffalo farts...or Wooly Mammoth farts, or Dinosaur farts if you want to go back 65- 250 some odd million years ago. You telling me that somehow cows are going to kill the planet with their farts??? When all these animals have been farting since before humans walked the earth? I don't think so. Sorry guys, "Scientists" used to say the worldwas flat too, but look what happend to that theory...

I belive i said cow FARMS not farts...

True cow farms do release alot of greenhouse gases also. But man is resposible for all the cow farms.

Ozone (o3) is a very unstable element. Oxygen (O2) is a very stable element. Molecules are always trying to become stable. O3 naturally becomes O2 however because of CFCs and as nox said methane gas from cow farms, more O3 molecules are being turned into O2 before they can be replenished.

[Demosthenes]

Ozone (o3) is a very unstable element. Oxygen (O2) is a very stable element. Molecules are always trying to become stable. O3 naturally becomes O2 however because of CFCs and as nox said methane gas from cow farms, more O3 molecules are being turned into O2 before they can be replenished.

Nope read my first link, this is patently untrue. I know its ponderous and long and will take most of the evening to plod through the Scientist-speak but all the relevant information is there for te taking!

[Buck Williams]

Republicans.......

For nearly a billion years, ozone molecules in the atmosphere have protected life on Earth from the effects of ultraviolet rays. In the past 60 years or so human activity has contributed to the deterioration of the ozone layer.

Only 10 or less of every million molecules of air are ozone. The majority of these ozone molecules resides in a layer between 10 and 40 kilometers (6 and 25 miles) above the Earth's surface in the stratosphere.



Each spring in the stratosphere over Antarctica (Spring in the southern hemisphere is from September through November.), atmospheric ozone is rapidly destroyed by chemical processes. Over the course of two to three months, approximately 50% of the total column amount of ozone in the atmosphere disappears. At some levels, the losses approach 90%. This has come to be called the Antarctic ozone hole.

The Antarctic ozone hole was discovered in 1985 by British scientists Joesph Farman, Brian Gardiner, and Jonathan Shanklin of the British Antarctic Survey.

The ozone "hole" is really a reduction in concentrations of ozone high above the earth in the stratosphere. The ozone hole is defined geographically as the area wherein the total ozone amount is less than 220 Dobson Units. The ozone hole has steadily grown in size (up to 27 million sq. km.) and length of existence (from August through early December) over the past two decades.

Chlorofluorocarbons (CFCs) are a family of chemical compounds developed back in the 1930's as safe, non-toxic, non-flammable alternative to dangerous substances like ammonia for purposes of refrigeration and spray can propellants. Their usage grew enormously over the years. One of the elements that make up CFCs is chlorine. Very little chlorine exists naturally in the atmosphere. But it turns out that CFCs are an excellent way of introducing chlorine into the ozone layer. The ultraviolet radiation at this altitude breaks down CFCs, freeing the chlorine. Under the proper conditions, this chlorine has the potential to destroy large amounts of ozone. This has indeed been observed, especially over Antarctica. As a consequence, levels of genetically harmful ultraviolet radiation have increased.

Chlorofluorocarbons (CFCs) are highly stable compounds that are used as propellents in spray cans and in refrigeration units. They are several organic compounds composed of carbon, fluorine, chlorine, and hydrogen. CFCs are manufactured under the trade name Freon (q.v.).

Developed during the 1930s, CFCs found wide application after World War II. These halogenated hydrocarbons, notably trichlorofluoromethane (CFC-11, or F-11) and dichlorodifluoromethane (CFC-12, or F-12), have been used extensively as aerosol-spray propellants, refrigerants, solvents, and foam-blowing agents. They are well-suited for these and other applications because they are nontoxic and nonflammable and can be readily converted from a liquid to a gas and vice versa.

Chlorofluorocarbons or CFCs (also known as Freon) are non-toxic, non-flammable and non-carcinogenic. They contain fluorine atoms, carbon atoms and chlorine atoms. The 5 main CFCs include CFC-11 (trichlorofluoromethane - CFCl3), CFC-12 (dichloro-difluoromethane - CF2Cl2), CFC-113 (trichloro-trifluoroethane - C2F3Cl3), CFC-114 (dichloro-tetrfluoroethane - C2F4Cl2), and CFC-115 (chloropentafluoroethane - C2F5Cl).

CFCs have been found to pose a serious environmental threat. Studies undertaken by various scientists during the 1970s revealed that CFCs released into the atmosphere accumulate in the stratosphere, where they had a deleterious effect on the ozone layer. Stratospheric ozone shields living organisms on Earth from the harmful effects of the Sun's ultraviolet radiation; even a relatively small decrease in the stratospheric ozone concentration can result in an increased incidence of skin cancer in humans and in genetic damage in many organisms. In the stratosphere the CFC molecules break down by the action of solar ultraviolet radiation and release their constituent chlorine atoms. These then react with the ozone molecules, resulting in their removal.

CFCs have a lifetime in the atmosphere of about 20 to 100 years, and consequently one free chlorine atom from a CFC molecule can do a lot of damage, destroying ozone molecules for a long time. Although emissions of CFCs around the developed world have largely ceased due to international control agreements, the damage to the stratospheric ozone layer will continue well into the 21st century.

Ozone is a molecule that contains three atoms of oxygen and thus has the formula O3.



Ozone was first discovered in 1839 by German scientist Christian Friedrich Schonbein.





NASA Graphic



It is a pale blue, relatively unstable molecule made up of three oxygen atoms. The ozone molecule is angular, polar, and diamagnetic. Both oxygen bond lengths (1.28 angstroms) are identical. It is formed from molecular oxygen (O2) by ultraviolet and extreme ultraviolet photolysis followed by recombination of atomic oxygen (O) with O2.The name ozone is derived from a Greek word meaning "to smell". It may also be formed by passing an electrical discharge through gaseous oxygen. It is characterized by a unique odor that is often noticed during electrical storms and in the vicinity of electrical equipment. In fact, the term ozone is derived from the Greek word ozein which means "to smell." The density of ozone is about 2.5 times that of O2. At -112 degrees C it condenses to a deep blue liquid. It is a powerful oxidizing agent and, as a concentrated gas or a liquid, is highly explosive. Excess oxygen atoms, also known as free radicals, oxidize materials that they contact and are associated with the aging process.

Ozone is a relatively simple molecule, consisting of three oxygen atoms bound together. Yet it has dramatically different effects depending on where ozone resides, it can protect or harm life on Earth. High in the atmosphere about 15 miles (24 km) up ozone acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems.

Closer to Earth, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants. Near Earth's surface, where ozone comes into direct contact with life forms, it primarily displays a destructive side. At ground level, ozone is a health hazard it is a harmful pollutant that causes damage to lung tissue and plants- it is a major constituent of smog.



Earth’s atmosphere

NASA GSFC Graphic

Because it reacts strongly with other molecules, large concentrations of ozone near the ground prove toxic to living things. Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC, also known as ozone precursors.



Environmental Protection Agency graphic

Strong sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. Many urban areas tend to have high levels of "bad" ozone, but other areas are also subject to high ozone levels as winds carry NOx emissions hundreds of miles away from their original sources.

At higher altitudes, where 90 percent of our planet's ozone resides, it does a remarkable job of absorbing ultraviolet radiation. In the absence of this gaseous shield in the stratosphere, the harmful radiation has a perfect portal through which to strike Earth. The amounts of "good" and "bad" ozone in the atmosphere depend on a balance between processes that create ozone and those that destroy it. An upset in the ozone balance can have serious consequences for life on Earth. Scientists are finding evidence that changes are occurring in ozone levels—the "bad" ozone is increasing in the air we breathe, and the "good" ozone is decreasing in our protective ozone shield.