Name: 臭氧層空洞的修復為何要延後十年？ (Here’s Why Repairing the Hole in the Ozone Layer Is Delayed by a Decade)
Uploaded: 2021-01-14T09:58:33.000Z
Duration: 5 min 17 s
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As of 2019, the earth is facing rising temperatures, severe storms, and we’re all pretty much

關係子句

The last thing anyone wants to hear right now is that our ozone, the gas that protects

us from the hazardous UV radiation, is still being destroyed.

In the last few years, scientists have seen a recent spike in ozone destroying chemicals,

It’s been a mystery as to where they were coming from until now.

When we talk about the “hole in the ozone,” what we actually mean is there’s a roughly

23-million-square-kilometer area that’s much thinner than it should be, and this is

mostly due its destruction from chlorofluorocarbons, or CFCs.

Now quickly, if you’re unfamiliar, the ozone is a very thin layer to begin with.

While around 90% of it sits in the stratosphere, it contributes a very small percentage to

It’s created when the sun’s rays hit O2 molecules, the kind of oxygen we breathe,

and splits them into individual oxygen atoms.

This gives them the opportunity to cling to other O2 molecules, creating O3: the ozone.

And if you haven’t already guessed, we like the ozone, like a lot.

That thin layer of O3 molecules soak up to 99% of UV light that would otherwise penetrate

the planet and make the earth uninhabitable.

CFC’s are man-made chemicals that come from things like refrigeration systems, propellant

devices, or insulation processes and when they escape into our atmosphere, they wreak

When sunlight breaks chlorine atoms off the CFC molecule, the chlorine jumps from O3 molecule

to O3 molecule, unscathed and destroying ozone in the process.

It only takes one chlorine atom to destroy over one hundred thousand ozone molecules

But none of this new to scientists. In fact, we’ve known about it for decades, and the

UN made an international treaty back in 1987 called the “Montreal Protocol” to completely

eliminate and stop the manufacturing of these chemicals.

It was the first universally ratified treaty and it received signatures from one hundred

We even did a whole video breaking down this historical effort.

Well, everything was looking pretty good, the ozone was recovering at the predicted

It was then, scientists noticed that the ozone’s recovery was more delayed than projections

There was a spike of the chemical called, CFC-11, also known as, trichlorofluoromethane,

which is commonly found in spray foam insulation.

Oh, and it’s also one of the most potent chemicals in destroying the ozone. Basically

the worst one that could be making a comeback right now.

Before 2012, CFC-11’s concentration was dropping by about 0.8% per year, but that rate

By 2018, a study out of Nature had scientists estimate that this could only happen with

Although they weren’t quite sure exactly where, they identified a region in East Asia.

In the latest study from May 2019, scientists used air samples from the international monitoring

network called Advanced Global Atmospheric Gases Experiment.

The two stations were from South Korea and Japan, which reported that the new emissions

Both of which have contributed to some 7,000 metric tonnes annually since the beginning

This is the first time anyone has broken the international treaty and it doesn’t seem

They sent out a public letter last year addressing their zero tolerance policy on the matter

of CFC’s and cracked down on companies using the product. But that’s only a fraction of

what could account to what the researchers call “rogue emissions.”

So there’s still a mystery as to where the rest of these CFC-11 spikes are coming from.

The emissions in China account for at least 40%, but what they’ve collected doesn’t

Plus, there’s the possible extra 60% they can’t locate at all.

With the current 13,000 metric tonnes of chemicals in our atmosphere, scientists predict there’s

already been a setback of a decade before the ozone truly recovers.

A question you might have is why anyone would still want to make CFC’s in the first place?

Well researchers from the Environmental Investigation Agency speculate CFC-11 is

cheap to make and a more efficient product to the alternatives.

As it stands right now, we monitor the atmosphere with the Advanced Global Atmospheric Gases

They have 15 monitoring stations based on islands and mountain tops worldwide.

But 15 stations is not enough to cover the entire planet, and it makes our overall monitoring

Let alone the expense and commitment it takes to collecting samples multiple times a day for

But this spike in CFC-11 just might be what scientists needed to see a bigger concern

at play; locating where these rogue emissions are coming from, and stopping them at the

If you want to know more about the feats we’re taking in environmental protection, subscribe,

and check our video on what happens if the world warms by just a couple degrees Celsius.

Thanks for watching, and I’ll see you next time on Seeker.

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臭氧層空洞的修復為何要延後十年？ (Here’s Why Repairing the Hole in the Ozone Layer Is Delayed by a Decade)

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