Other causes, including solar radiative output variations, are thought to be less important, but they are also far less certain. (gcrio.org)
He claimed that the Maunder Minimum coincided in time with an era of colder weather, and that by implication the absence of magnetic activity was accompanied by a net fall in the total radiative output of the Sun. (stsci.edu)
The variable radiative output of the Sun is a prime external driver of the Earth's climate system. (link.springer.com)