Re: What's that in the sky?
"Really, how much else is there to see in the sky/stratosphere?"
Lots of stuff, actually. Clouds, carbon dioxide, CFCs, cow farts, car exhaust, climate change... oh wait, those all start with the letter "c." But really, lots of climate research focuses on levels of various gasses and particles in the atmosphere--oxygen, water, ozone, CO2, nitrogen and methane are always popular, but minor ones (CFCs, volcanic ash) can also have an outsize effect on the environment too. Most of these are currently studied by putting sensors on balloons and satellites; which, arguably, makes the stratosphere easier to study than the deep ocean.