One of the comments I often hear from people who are dubious about a warming climate is that the change is occurring naturally due to increases in the sun’s output. But is this really true?
We do know that solar output is a factor in long-term changes in climate. For example, the wax and wane of ice ages has been linked to small changes in the amount of sunlight received on earth due to changes in Earth’s orbit around the sun. For example, when perihelion is in July instead of January (we just passed it two days ago), that can make summers a little warmer and winters a little colder than the present climate. The current trend in climate due to these orbital variations should be towards cooler temperatures as we move towards the next ice age many thousands of years from now.
You can read a good description of this topic at https://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm along with some discussion about methodology.
