Wayne Stollings wrote:
The measured temperature compared to the sunspot activity in recent years does not correlate.
There is a solar signature in the 20th Century and in recent temperature change.Laptukhov and Laptukhov 2010Based on large set of observational data (for ∼100 years), it has been demonstrated that the air temperature at midlatitudes in the years close to solar activity maximum is on average higher than in other years by DT = 0.11–0.15 degrees at many meteorological stations. The DT parameter is negative and smaller in magnitude near the equator and poles. A correct (in the energetic sense) physical mechanism by which solar and geomagnetic activities affect the ground level air temperature has been proposed.
This led the authors to speculate that the effect of Carbon Dioxide is not very important (though I disagree that it should be ignored).Echer et al. 2012The air surface temperature is a basic meteorological parameter and its variation is a primary measure of global, regional and local climate changes. In this work, the global, hemispheric and latitudinal averaged air surface temperature time series, obtained from the NASA/Goddard Institute for Space Studies (GISS), and the Sunspot Number (Rz) for the interval 1880–2005, are decomposed in frequency bands through wavelet multi-resolution analysis. We have found a very low correlation between global, hemispheric and latitudinal averaged air surface temperature and Rz in the 11 yr solar cycle band (8–16 years) from ∼1880 to ∼1950. Afterwards the correlation is higher. A very significant correlation (R ∼0.57 to 0.80) is found in the ∼22 yr solar Hale cycle band (16–32 years) with lags from zero to four years between latitudinal averages air surface temperature and Rz. Therefore it seems that the 22 yr magnetic field solar cycle might have a higher effect on Earth's climate than solar variations related to the 11 yr sunspot cycle.Cho et al. 2012We investigate whether the global temperature anomaly is associated with the solar North-South asymmetry using data archived approximately for five solar cycles. We are motivated by both the accumulating evidence for the connection of Galactic cosmic-rays (GCRs) to the cloud coverage and recent finding of the association of GCR influx and the solar North-South asymmetry. We have analyzed the data of the observed sunspot, the GCR influx observed at the Moscow station, and the global temperature anomaly. We have found that the mean global temperature anomaly is systematically smaller (∼0.56 in the unit of its standard deviation) during the period when the solar northern hemisphere is more active than the solar southern hemisphere. The difference in the mean value of the global temperature anomaly for the two data sets sub-sampled according to the solar North-South asymmetry is large and statistically significant. We suggest the solar North-South asymmetry is related to the global temperature anomaly through modulating the amount of GCR influx. Finally, we conclude by discussing its implications on a climate model and a direction of future work.
Your claim is that because the Sunspot Number was flat over the last 30 years, the sun could not have contributed to Global Warming during this timeframe. The role of equilibrium needs to be considered, but even accounting for equilibrium does not give a large solar contribution over the late-20th Century. However, if more adequate solar indicies like the Geomagnetic AA Index are used, a larger portion of the warming can be explained by solar activity.
We can see in this figure from Georgieva et al. 2012
that while the SSN was declining, the AA Index continued to increase, allowing for more of the warming to be explained by solar variance.
I've been doing some research on solar activity and temperature change on Google Scholar, and I am actually surprised at the number of papers that support a skeptical position. Arguably, there are just as many papers that I've seen on Google Scholar that support a strong solar effect on temperatures, as there are that do not support a strong solar effect. Most of the claims that do not support a large solar forcing are because they only account for solar irradiance and claim that the amplitude of the recent warming during the 20th Century was insufficient to be explained by solar effects. Accounting for any solar effects on cloud cover can easily give a large solar contribution to the 20th Century warming observed.