JOE: Nearly 40 years ago scientists sounded the environmental alarm bells because they'd discovered something terrifying way up there, a growing hole in the ozone layer. And life as we know it was speeding towards a sizzly end if we didn't act fast. So, we did.
JOE: Between us and the vast vacuum of outer space is a whole lot of sky but if we want to get technical it's the atmosphere. Several layers of gasses that keep us cosy, and well, alive down here.
About 20 to 30 kays up in the stratosphere is the ozone layer which plays an essential role in our survival. Ozone is a molecule that's made up of three oxygen atoms and these little guys suck up ultraviolet radiation from the sun. In fact, the ozone layer absorbs about 98 percent of the UV rays that the sun spits at Earth.
JOE: Which is a fabulous thing for us because while we do need some of the sun's UV rays to produce vitamin D and help plants photosynthesise. Too much UV radiation can damage DNA and cause things like skin cancer and even blindness. Without any ozone layer we wouldn't be able to go outside or grow food and eventually all life on Earth would die out, and in the 1980s that was a very real threat.
In 1985 scientists discovered that ozone levels around the Antarctic were dropping, fast, and we were on track to completely destroy the ozone layer by 2050.
JOE: The whole situation was pretty bleak and the world was in despair but how did something so catastrophic happen in the first place?
Well, it all came down to pollution from chemicals called chlorofluorocarbons or CFCs. Back then, CFCs were used in lots of products. When CFCs are released into the atmosphere and exposed to UV rays, they breakdown and rip the ozone molecules apart which scientists say created the hole.
JOE: Add on the fact that CFCs hang around up there for between 50 and 150 years. Yeah, that's a lot of damage.
RAFE POMERANCE, WORLD RESOURCES INSTITUTE 1987: I think we should all be aware of the size of the challenge we are faced with.
In September 1987 at a conference in Montreal, world leaders came together to take action. Every single country signed the Montreal Protocol which officially recognised the impacts on the ozone layer and listed steps for countries to phase out their ozone-munching chemical usage.
JOE: Today CFCs are a thing of the past and the ozone layer is bouncing back, which experts say is all thanks to the ground-breaking Montreal Protocol. They even reckon that the ozone layer could fully recover for most of the world by 2040. And the bigger holes in the Arctic and Antarctic by 2045 and 2066 respectively.
STÉPHANE DUJARRIC, UNITED NATIONS: The phase out of nearly 99 percent of banned ozone-depleting substances has succeeded in safeguarding the ozone layer, leading to notable recovery of the ozone layer.
JOE: Ultimately what the Montreal Protocol has proved is that the world can come together to create necessary change. So, can we repeat history for the current climate crisis? Well, there's still a lot of work to do.
