Atmospheric Carbon: Whence the discrepancy?
There's no discrepancy here.  The first graph (total emissions from fossil fuels and industry; Fig. 4a of Le Quéré et al, 2016) is an input to the system, and the second graph is a proxy for the amount stored in one part of the system (the atmosphere).  For the latter, it probably makes more sense to look at the total atmospheric growth rate (Fig. 4c of Le Quéré et al), which has remained positive for decades.

Note that when you add in emissions from land-use it's likely that the total emissions have continued to increase.  But that doesn't detract from the main point here: if you keep putting stuff in the bucket, the amount in the bucket will continue to increase.  You don't need to invoke any feedbacks for that to happen.