"
For general purposes, the energy output of the sun can be considered constant. This of course is not entirely true. Scientists have shown that the output of the sun is temporally variable (Figure 4). Some researchers have also suggested that the increase in the average global temperature over the last century may have been solar in origin. This statement, however, is difficult to prove because accurate data on solar output of radiation only goes back to about 1978. "
http://www.eoearth.org/article/Solar_radiation



I was NOT talking about sunspots ( 11 year cycle), but the longer cycles that many here seem to be ignorant of.


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accurate data on solar output of radiation only goes back to about 1978.
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So how can ANYONE tell me that they know there is NO long-term variation, when other indicators ( Earth's past climate amoung them) have shown there to be?


Don Firth,

As I have a BS degree in physics and astronomy, and have 30 years experience working in the field of satellite data collection (EO-1 Data Manager as well as other positions) and interpretation, perhaps you might tell me YOUR credentials in the field of solar flux determination?