What was done
For the period 1856 to 2002, the authors compared the form of statistical fluctuations in the intermittency of solar flare activity with the form of statistical fluctuations in earth's near-surface air temperature as expressed as anomalies relative to the 1961-1990 mean.

What was learned
Both parameters studied were shown to possess time series properties characteristic of dynamical stochastic processes bearing imprints of a particular form of variability called a Levy-walk.  Building upon this observation, the authors report that "the affinity of the scaling exponents obtained through our analysis suggests that the earth's temperature anomalies inherit a Levy-walk memory component from the intermittency of solar flares," which in turn suggests that earth's near-surface air temperature fluctuations arise from variations in solar flare activity.

Two other interesting points are evident in their analysis.  First, the best correspondence to solar flare variability was obtained for ocean, as opposed to land, temperatures.  This finding is especially significant, since the world's oceans would be expected to better mirror solar activity, due to their much greater compositional homogeneity and higher heat capacity.  Second, the authors' analysis dealt with short timescales, ranging from weeks to months.  They note that over timescales of tens to hundreds of years, correlations between solar activity and temperature have been well established, citing a number of relevant studies.  The significance of the shorter timescale correlation they discovered lies in the fact that it implies a stronger physical connection between earth's climate and solar activity than most scientists had previously thought likely.

What it means
In the words of Schewe et al. (2003), Scafetta and West's analysis "suggests that for the large part, variations in global temperatures are beyond our control and are instead at the mercy of the sun's activity."

Reference
Schewe, P.F., Stein, B. and Riordon, J.  2003.  The American Institute of Physics Bulletin of Physics News. No. 642. 18 June 2003.
Reviewed 30 July 2003