Name: 【TED】Sean Davis: Can we solve global warming? Lessons from how we protected the ozone layer (Can we solve global warming? Lessons from how we protected the ozone layer | Sean Davis)
Uploaded: 2019-02-12T22:01:27.000Z
Duration: 9 min 51 s
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and if this room is representative of the country we live in,

that means about 60 percent of you, so maybe from about there over,

don't strongly trust me for information on the causes of climate change.

Now, I promise to tell the truth tonight,

[The Paris Climate Accord is a product of the recognition

that climate change is a global problem ...]

This statement was not made by President Obama.

and it wasn't about climate change and the Paris Climate Accord.

It was actually about the Montreal Protocol

Now, I'm sure that many of you aren't familiar with this environmental problem,

because it's a rare environmental success story.

because sometimes, we need to examine the world we've avoided

in order to find guidance for the choices we make today.

when some questionable choices were made:

first of all -- hoo -- hairstyles. (Laughs)

Second of all, objectively terrible quantities of hairspray,

man-made chemicals that were used as propellant in aerosol spray cans.

And see, it turns out these CFCs were a problem

because they were destroying the ozone layer.

Now I'm sure most of you have heard of the ozone layer,

Well, quite simply, the ozone layer is earth's sunscreen,

which is mostly about 10 to 20 miles up above our heads,

and compress it down to the surface of the earth,

it would form a thin shell only about two pennies thick,

And that thin shell does an amazing amount of work, though.

It filters out more than 90 percent of the harmful UV radiation

And while I'm sure many of you enjoy that suntan that you get

from the remaining 10 percent, it causes a lot of problems:

to say that a threat to the ozone layer is a threat to human safety.

And actually, ironically, it was human safety

that motivated the invention of CFCs in the first place.

You see, in the early days of refrigeration,

refrigerators used toxic and flammable chemicals

For good reason, the refrigeration industry

synthesized the first commercially viable CFCs.

And in fact, Midgley famously inhaled CFCs and blew out a candle

to demonstrate, at a scientific conference,

And in fact, as a scientist, I can tell you there is no way

you could get away with that kind of antic today.

They allowed what we now know as modern-day refrigeration

So it wasn't actually until over 40 years later, in the 1970s,

when scientists realized that CFCs would break down high in the atmosphere

And this finding really set off a lot of public concern.

It led, ultimately, to the banning of CFC usage in aerosol spray cans

in the US and a few other countries in 1978.

because CFCs were used in much more than just spray cans.

In 1985, scientists discovered the Antarctic ozone hole,

scientists expected maybe a five or 10 percent reduction

But what they found over the course of less than a decade

was that more than a third of the ozone had simply vanished,

over an area larger than the size of the US.

And although we now know that CFCs are the root cause of this ozone hole,

at the time, the science was far from settled.

So that quote that I started this talk with,

about the Montreal Protocol, from President Reagan --

that was his signing statement when he signed the Montreal Protocol

after its unanimous ratification by the US Senate.

And this is something that's truly worth celebrating.

In fact, yesterday was the 30th anniversary of the Montreal Protocol.

ozone-depleting substances are now declining in our atmosphere,

and we're starting to see the first signs of healing in the ozone layer.

And furthermore, because many of those ozone-depleting substances

【TED】Sean Davis: Can we solve global warming? Lessons from how we protected the ozone layer (Can we solve global warming? Lessons from how we protected the ozone layer | Sean Davis)

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【TED】Sean Davis: Can we solve global warming? Lessons from how we protected the ozone layer (Can we solve global warming? Lessons from how we protected the ozone layer | Sean Davis)

crisis

applause

catastrophic

climate