Oh, wow, oh, oh, whoa, oh, wow.

Oh, wow.

Oh, wow. Hello, you're listening to The Science of Everything podcast, Episode 89, the atmosphere.

I'm your host, James Fodor.

In this episode, we're going to talk about Earth's atmosphere, particularly focusing on the composition,

we'll look at the different atmospheric layers, and we'll also talk a bit about the Karmann line,

the ozone layer, and the ionosphere.

So to give you a general overview of the Earth's atmosphere and some of its major properties.

No specific recommended pre-listing for this episode, although this is part of a series of connected episodes,

which is leading up to talking about the science of climate change.

So the previous two episodes,

cartography and earth seasons and geography of planet Earth, may be relevant. Also, a few points from episode 42 gases and gas laws may be pertinent as well, but mostly this is standalone.

The atmosphere refers to the envelope of gases that surrounds the planet Earth.

And the composition of Earth's atmosphere consists mostly of nitrogen, 78%.

Now that's contrary to what most people, I think, naively think, which is that oxygen is the main component of Earth's atmosphere.

Oxygen is actually only the second largest component, 21%, this is by volume.

And the third largest component is argon, which is an inert gas that doesn't really react with anything.

It's a noble gas, so we don't hear about it very often.

The fourth most common component by volume of the Earth's atmosphere is carbon dioxide,

and it's been increasing in concentration in recent years, which we'll talk about when we get to

discussing the science of climate change. Now, I should also say that these figures, 70% nitrogen,

21% oxygen, 1% argon, and trace other gases are for dry air, because the

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