Carbon Dioxide. The science isn't easy

Sources of CO2 and how much stays in the atmosphere, how and where it is measured, it isn't as simple as it sounds.

How much is man made?
Different sites say different things.
Why does it rise?
There are mysteries still.
Skeptical Science has a page
How much is from volcanoes is a real mystery.
How do volcanoes effect climate?
More mystery.
Many interesting things are online. Some people are skeptical.
I can't blame them, I mean,

Why an active volcano to measure CO2?
Lots of interesting information on that blog.
Monitoring CO2 elsewhere.
Greenhouse Background

This entry is mostly saving links so I can look into this later.