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Hole In The Ozone Layer Smallest In 29 Years (weather.com)
An anonymous reader quotes the Weather Channel:
The hole in the ozone layer over Antarctica is the smallest it's been since 1988, NASA said. According to a press release, the hole in the Earth's ozone layer is 1.3 million square miles smaller than last year and 3.3 million square miles smaller than 2015... This year, the hole grew to 7.6 million square miles. NASA and NOAA scientists said warmer temperatures and a stormier upper atmosphere helped keep damaging chemicals chlorine and bromine from eating ozone from the layer that protects the Earth's surface from harmful ultraviolet rays... The hole that hovers over Antarctica has been slowly recovering, scientists say, due to an international ban on harmful chemicals that were previously used in refrigerants and aerosols.
The hole was its largest in 2000 and measured 11.5 million square miles. Although recovery is underway, the size of the hole remains large compared to the 1980s, when the hole was first detected, NASA noted. And while there has been significant healing of the ozone layer in recent years, some scientists say full healing is a slow process and will not occur until sometime in the 22nd century, Yale Environment 360 reports. Others expect the Antarctic ozone hole to recover back to 1980 levels around 2070, NASA said.
The hole was its largest in 2000 and measured 11.5 million square miles. Although recovery is underway, the size of the hole remains large compared to the 1980s, when the hole was first detected, NASA noted. And while there has been significant healing of the ozone layer in recent years, some scientists say full healing is a slow process and will not occur until sometime in the 22nd century, Yale Environment 360 reports. Others expect the Antarctic ozone hole to recover back to 1980 levels around 2070, NASA said.
This is a really good demonstration that we can handle serious environmental problems if we put in the effort, and we can do so without substantial economic impact. Yes, global warming is a more large scale problem than ozone depletion but the basic point remains. We've now essentially solved both the ozone hole problem and acid rain, through a combination of market forces, better technology, and government incentives. We can do the same for global warming. Let's actually do that. Unfortunately, over the last few years, some aspects of the right in the US have become so against helping the environment that they are blocking any serious attempt to deal with these issues, and we'll all going to suffer as a result.
That's why we have global warming. Shouldn't have covered it up so some of the steam can come out, keep things cooler. I don't know what NASA is doing, I think for three minutes and I come up with better ideas than all of NASA scientists. This is why Donald Trump got elected wake up.
"First they came for the slanderers and i said nothing."
he pushed through an amendment to the clean air act in 1989 to ban the use of ozone depleting chemicals
It's a good thing this happened in the 70's and 80's when conservatives were still reasonable. The montreal protocol would have never passed today. Australians and those in the southern united states would be red and blistered and hollering about "hands off my fridge" and liberal conspiracies about invisible rays.
The Montreal Protocol is an international agreement to reduce emissions of ozone-depleting gases. It was ratified in 1989 with leadership from the United States, and has been very successful at reducing the ozone hole. President Reagan and President Bush (41) both supported the Montreal Protocol. Reagan overruled members of the cabinet who opposed the agreement. The State Department under the Bush administration warned that we cannot wait on acting to prevent climate change. History should remember these Republicans favorably as accepting science and taking action to mitigate climate change. Modern Republicans should take note. The Republican Party was not always willing to deny science for the purpose of helping big business.
I can't tell if you're serious or joking. I reread your post about 5 times and I just can't tell.
Poe's law. You really can't tell sarcasm from cluelessness any more.
http://knowyourmeme.com/memes/poes-law
http://www.geoffreylandis.com
Before we pat ourselves on the back, we should remember that the Trump administration just appointed a man to the EPA advisory board who believes that the air in America is, "a little too clean for optimum health".
No, I'm not joking. That's what he said. .
https://www.independent.co.uk/...
You are welcome on my lawn.
Fixing the ozone hole (freon) by replacing freon with hydrofluorcarbons was a big mistake, they are far more potent greenhouse gases. Don't pat humans on the back yet, we're not that smart. Ref: https://phys.org/news/2017-11-... Citation provided.
Why guess when you can know? Measure!
The annual ozone hole is a natural phenomenon, but historically the hole was a small fraction of the size than what we have had since the 1980's.
https://ozonewatch.gsfc.nasa.g...
Compare the 1979-1982 ozone hole size and Antarctica ozone levels before 1983 to after.
That the ozone depletion/ozone hole continued to grow after the Montreal agreement was predicted.
The problem we faced is that the rate of production of CFCs vastly exceeded the rate of degradation of CFCs in the atmosphere so we were facing an accelerating rate of ozone depletion. The ozone hole was growing rapidly in size every year, and the global ozone levels were decreasing.
https://www.esrl.noaa.gov/csd/...
The problem CFCs and related compounds have a very long lifetime in the lower atmosphere, on the order of a century, and on the order of decades in the stratosphere. Once a CFC is degraded by UV and releases a free chlorine or bromine, the free Cl or Br atom can continue to catalyze ozone to O2 for a few years before the free atom binds with hydrogen and falls back down to the lower atmosphere and get washed out.
Here's a document with graphs showing the continuing post-Montreal increase and subsequent drop-off in atmospheric concentrations.
https://www.esrl.noaa.gov/csd/...
Here's an executive summary of the situation in 2014.
https://www.esrl.noaa.gov/csd/...
Actions taken under the Montreal Protocol have led to decreases in the atmospheric abundance of controlled ozone-depleting substances (ODSs), and are enabling the return of the ozone layer toward 1980 levels.
The sum of the measured tropospheric abundances of substances controlled under the Montreal Protocol continues to decrease. Most of the major controlled ODSs are decreasing largely as projected, and hydrochlorofluorocarbons (HCFCs) and halon-1301 are still increasing. Unknown or unreported sources of carbon tetrachloride are needed to explain its abundance.
Measured stratospheric abundances of chlorine- and bromine-containing substances originating from the degradation of ODSs are decreasing. By 2012, combined chlorine and bromine levels (as estimated by Equivalent Effective Stratospheric Chlorine, EESC) had declined by about 10–15% from the peak values of ten to fifteen years ago. Decreases in atmospheric abundances of methyl chloroform (CH3CCl3), methyl bromide (CH3Br), and chlorofluorocarbons (CFCs) contributed approximately equally to these reductions.
Total column ozone declined over most of the globe during the 1980s and early 1990s (by about 2.5% averaged over 60S to 60N). It has remained relatively unchanged since 2000, with indications of a small increase in total column ozone in recent years, as expected. In the upper stratosphere there is a clear recent ozone increase, which climate models suggest can be explained by comparable contributions from declining ODS abundances and upper stratospheric cooling caused by carbon dioxide increases.
The Antarctic ozone hole continues to occur each spring, as expected for the current ODS abundances. The Arctic stratosphere in winter/spring 2011 was particularly cold, which led to large ozone depletion as expected under these conditions.
Total column ozone will recover toward the 1980 benchmark levels over most of the globe under full compliance with the Montreal Protocol. This recovery is expected to occur before midcentury in midlatitudes and the Arctic, and somewhat later for the Antarctic ozone hole.