What was done
Ring widths of whitebark pine (Pinus albicaulis Englem.) and subalpine larch (Larix lyallii Parl.) trees growing at three high-elevation sites in the Selway-Bitterrot Wilderness Area (SBW) near the border of Idaho and Montana, USA, were used to develop tree-growth chronologies that were subsequently compared, in the words of the authors, to "monthly temperature and precipitation data from individual station records, gridded climate datasets, and regionally averaged instrumental records," in order to reconstruct a history of the area's summer temperature anomalies over the period AD 1544 through 1998.

What was learned
Kipfmueller reports, first of all, that "in the SBW, as in many other areas [our italics and bold], volcanic eruptions and solar variability" -- or, with respect to the latter factor, what is more explicitly stated in the paper's abstract to be "reduced solar activity" -- "appear to result in pronounced cooling at interannual to decadal scales." In addition, he states that "anomalous warming over the 20th century," such as that portrayed by the hockeystick temperature history of climate-alarmist fame, "was not as evident in this reconstruction as has been reported elsewhere." Giving even more support for the reality of this latter result, Kipfmueller also notes that "the instrumental record, both at individual stations, in the divisional record, and from gridded temperature records, did not indicate significant trend in summer temperature (AD 1928-1998)."

What it means
Once again, we are led to say: Not much global warming here! And this being the case in a place that is clearly demonstrated to be responsive to changes in solar and volcanic activity, we are led to wonder why there has been no response to the past century's historic increase in the air's CO2 content.

Well, to be totally truthful, we actually don't wonder, as we believe that a number of negative feedback phenomena of both a biological and physical nature tend to largely counter the modest greenhouse effect of the rising atmospheric CO2 concentration, rendering its impetus for warming too small to even detect.