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None, but I'm not 100% sure. I'm pretty sure any matter is going to absorb SOME energy from solar radiation.

In so far as this issue is pertinent to climate change the important issue is 'how much?'

This link shows the relevant information clearly.

http://www.google.co.uk/imgres?imgurl=ht...

Another important issue is so what? Whatever solar radiation gets absorbed in the atmosphere certainly won't get re-emitted in that form because the air temperature is well below what it required. Most of it will just heat the troposphere anyway.

Helium seems like it wouldn't absorb much but even it absorbs some

Obviously not much helium in atmosphere but it is a molecule composed of one atom.

My link won't post. Hmmm