On: Research: No rise of atmospheric Co2 fraction in past 160 years

Here's the actual citation http://www.agu.org/pubs/crossref/2009/2009GL040613.shtml titled "Is the airborne fraction of anthropogenic CO2 emissions increasing".

I'm no expert in climatology, but the science of other complex systems (e.g. medicine) often produce conflicting studies. Why should climatology be any different?