'Furthermore, FS is highly anticorrelated with cosmic ray fluxes
reaching Earth on a wide range of timescales [60]. This makes any
relationship of FS with UV emissions and top-down solar forcing a
relevant factor in the considerable debate about reported correlations
between climate (in particular global or regional cloud cover) and
GCRs. Indeed some authors have noted that apparent solar cycle
variations in cloud cover are in better agreement with the UV
irradiance variation than that of GCRs [61–63], although we note that
other studies that have tried to discriminate between electromagnetic
irradiance and direct cosmic ray effects do find some evidence for the
latter [64, 65]. A great many palaeoclimate studies have found links
between regional or local climate indicators and cosmogenic isotopes
and so it has been argued that this is either evidence for a direct
cosmic ray effect or that the cosmic rays are proxy indicators for the
correlated irradiance variability [66]. In particular, the much cited
and much debated paper by Bond et al [67] revealed a persistent
correlation during the Holocene between ice-rafted debris in the North
Atlantic region and cosmogenic isotopes. The results presented here
and in the recent paper by Woollings et al [26] suggest that solar UV
variability and top-down solar forcing can introduce regional changes
in the troposphere in the region studied by Bond et al and that these
may vary on centennial timescales, as recently reported in the Central
England temperature records by Lockwood et al [25]. The implication is
that seasonal/regional evaluation of past and future climate change
will be improved by models with adequate resolution in the
stratosphere to reproduce top-down solar forcing.'
http://iopscience.iop.org/1748-9326/5/3/034008/fulltext#erl358854s2
There is a top down influence on regulation of the Antarctic
Circumpolar Current - and hence the Humbolt Current and ENSO. ENSO
and clouds are connected through sea surface temperature.
http://www.springerlink.com/content/m025w8n112540176/
www.cfa.harvard.edu/~wsoon/EarlyEarth07-d/ZhuHackKiehlB07.pdf
Has cloud cover changed? It is far and way the major cause of warming
in the satelite era - I'll link to a discussion of mine but do check
the TOA radiant flux.
http://sciencefile.org/SciFile/component/content/article/1557-an-empirically-based-1st-order-differential-global-energy-model-cloud-changes-in-the-satellite-era-
Stick your head outside your usual box and see which way the wind is
blowing.