that variation in irradiance is plus or minus one tenth of one percent
Which is 1.3 watts per square meter at the top of the atmosphere. That's almost the same as the current estimate of heating forcing from from elevated levels of CO2.
Nice back of the envelope calculation! but you're off by a factor of 6.
Solar irradiance is absorbed by the disk area of the earth, pi r^2. But the earth's surface area is 4 pi r^2. And the solar energy absorbed is multiplied by the (1-albedo). So you're off by 4/(1-a), where a is about 0.30 to 0.35.
... and then you're assuming the difference between zero solar activity, and current solar activity. But over the time scale over which the global warming we're discussing occurs, the change in TSI isn't that high. Here's a graph of the historical Total Solar Irradiance:
http://lasp.colorado.edu/home/...
and the variation between 1900 and 2015 is considerably less than that.
I hate to keep harping on the same things, but the effect of solar variability has been analyzed in mind-numbing detail in the last few decades, and it just isn't there.
Two obvious problems with the assertion. First, decades aren't a very long span of time. We don't know how much solar variability there has been before we started reliably measuring it late last century.
We know that it doesn't explain the warming this century.
Second, there's still that matter of the ideological and institutional bias
With no actual evidence, you are assuming ideological and institutional bias as in input assumption. You're assuming NOAA is biased. NASA is biased. The National Science Foundation is biased. The National Climatic Data Center is biased. The Berkeley Earth Surface Temperature project is biased. The British Met office (formerly the Meteorological Office) is biased. The Climate Research Unit is biased. The Japanese Meteorological agency is biased. The Australian Bureau of Meteorology is biased. The Commonwealth Scientific and Industrial Research Organization is biased. The Centre National de la Recherche Scientifique is biased. The Max-Planck-Institut für Meteorologie is biased
These have all made models and measurements confirming the greenhouse effect. ...isn't it slightly stretching credibility that all of these institutions-- and many others-- on four continents, all happen to be biased, and all biased in exactly the same way?
But, yes, if you assume that pretty much everybody who has ever studied the field is biased, and you can ignore their work... well, yes, you can ignore a heck of a lot of data, yes indeed.