Above is the trend in Net Primary Productivity (NPP - green curve) from 1982 to 1999 according to Nemani et al, Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999.
And here again is the curve we discussed on Tuesday from Zhao and Running for the same thing from 2000-2009 (also green curve):
(Note that the earlier paper also involved the same University of Montana group, along with other collaborators).
On Tuesday, I offered my opinion that the second set of data is not a statistically adequate basis to say that there has been a "reduction" in NPP over that timeframe.
A more involved question is this: can we look at these two sets of data together and confidently infer at least this much: the NPP trend is getting worse than it used to be?
In the interests of time, I will offer an analysis tomorrow. In the meantime, readers are encouraged to offer their opinions...