I know you're talking about solar flares above, but thought this might still apply. This quote is from Hansens (2006b) paper that generated the "Dangerous" article. It's from section3.3.3, entitled Solar Irradiance, of the 'Transient' part of the total JGR submission that he then split.
"Ample evidence for longterm solar change and a link to climate has long been recognized
[Eddy, 1976], and solar models admit the possibility of such change."
& "At least until precise measurements of irradiance extend over several decades and more comprehensive solar models are available, solar climate forcing is likely to remain highly uncertain. ~[Hansen 2006b]
~Sam

Pyrolysis creates reduced carbon! ...Time for the next step in our evolutionary symbiosis with fire.