Evidence of new ozone depletion baffles scientists

[jserraglio]

Washington Post

The rescue of the planet’s protective ozone layer has been hailed as one of the great success stories of modern environmental regulation — but on Monday, an international team of 22 scientists raised doubts about whether ozone is recovering as expected across much of the world.
“We’ve detected unexpected decreases in the lower part of the stratospheric ozone layer, and the consequence of this result is that it’s offsetting the recovery in ozone that we had expected to see,” said William Ball, a scientist with the Physical Meteorological Observatory in Davos, Switzerland.
In 1987, countries of the world agreed to the Montreal Protocol, a treaty designed to phase out chlorofluorocarbons, or CFCs, responsible for destroying ozone in the stratosphere. The protocol has worked as intended in reducing these substances, and early healing of the ozone “hole” over Antarctica has been subsequently hailed by scientists.
But the study by Ball and his colleagues — a team of scientists including researchers based in the United States, Britain, Canada, Switzerland, Sweden and Finland — focused instead on the lower latitudes, where the vast majority of humans live. The research was published in Atmospheric Chemistry and Physics on Tuesday.
There, the scientists found a relatively small but hard-to-explain decline of ozone in the lower part of the stratosphere, the layer of the atmosphere that extends from about six miles to 31 miles above the planet’s surface, since the year 1998. Meanwhile, the upper stratosphere has been recovering.
“The precise cause of the trend is unknown but could be related to changes to the stratospheric circulation, which has a large influence on how ozone is distributed,” said Ryan Hossaini, an ozone expert at the University of Lancaster in Britain, who was not involved in the study, in an emailed comment. Those changes, in turn, could be tied to climate change.
There’s also a possibility that a new class of chlorine-containing chemical compounds not limited by the Montreal Protocol, dubbed “very short-lived substances,” could be contributing to the problem. The most prominent of these is dichloromethane, which has a wide range of industrial uses, including as a paint stripper.
Concentrations of the compound have been increasing in the atmosphere, and because of the compound’s relatively short lifetime, it is not regulated now under the Montreal Protocol.
At the same time, though, it’s not clear that there’s enough of it in the atmosphere to be causing what scientists are now observing.
“Although so-called very short-lived substances — some of which are increasing in the atmosphere — can contribute to ozone loss, they are very unlikely to be the main driver of the reported downward ozone trend based on their current abundance,” Hossaini said.
It all amounts to a mystery but a troubling one, because ozone protects life at the surface from incoming ultraviolet radiation, and any thinning of total ozone in the stratosphere is cause for concern.
“At the moment, there’s no proof of what’s causing it but there are some reasonable hypotheses that need to be investigated,” Ball said.
“We’re raising the alarm that we need to very rapidly investigate whether it’s the short-lived compounds, whether it’s a climate change response, whether our models aren’t quite doing the right job, or whether there’s something wrong with the data,” he said.
The political implications of the new research are not immediately clear, but Ball cautioned that it certainly does not mean that the Montreal Protocol isn’t working. It just means scientists must figure out what is going on — the cause of the new trend “urgently need to be established,” the new study says.
In the meantime, the new research raises questions about whether additional extensions of the protocol, which is designed to be updated based on new scientific developments, may be necessary to deal with the new findings of an ozone downtrend in the lower stratosphere.
“The future evolution of ozone layer will depend on the interplay between emissions of non-Montreal Protocol controlled [ozone depleting substances], and on what happens with our climate,” said Paul Young, a climate scientist also based at Lancaster University, in an emailed comment.

[jbuck919]

If they can discover a planetary system in another galaxy, as has recently been done, then they can figure this out too.

[jserraglio]

If they can discover a planetary system in another galaxy, as has recently been done, then they can figure this out too.

That's the easy part; doing something to reverse any depletion given the current retrograde political climate will be far less of a sure bet.

[jbuck919]

If they can discover a planetary system in another galaxy, as has recently been done, then they can figure this out too.

That's the easy part; doing something to reverse any depletion given the current retrograde political climate will be far less of a sure bet.

We weren't promised a rose garden, j. Our time here is limited, and any one of a number of things could cause the entire species to go the way of all flesh at any moment. Expectations of species immortality based on political hope are as much the stuff of science fiction as thinking that our descendants will prosper on other planets. With apologies to St. Paul, there abide these three things: faith, hope, and love. But the greatest of these is hope.

[jserraglio]

We weren't promised a rose garden, j. Our time here is limited, and any one of a number of things could cause the entire species to go the way of all flesh at any moment. Expectations of species immortality based on political hope are as much the stuff of science fiction as thinking that our descendants will prosper on other planets. With apologies to St. Paul, there abide these three things: faith, hope, and love. But the greatest of these is hope.

The death of the race doesn't keep me up at nite, my four toddler grandkiddies do.

[jbuck919]

We weren't promised a rose garden, j. Our time here is limited, and any one of a number of things could cause the entire species to go the way of all flesh at any moment. Expectations of species immortality based on political hope are as much the stuff of science fiction as thinking that our descendants will prosper on other planets. With apologies to St. Paul, there abide these three things: faith, hope, and love. But the greatest of these is hope.

The death of the race doesn't keep me up at nite, my four toddler grandkiddies do.

The other part of your post disappeared. You are blessed, as I will never be, to have grandchildren. They will probably make it, as will many generations after them. Nevertheless, we exist on a thread extending from a bare link to a crescent moon, something that you as a very educated person know as well as I do.