[defrost]

It's certainly legitimate to question the role of solar variability in climate change, and it's absolutely something that has been looked at seriously.

The consensus, with increasing solidarity, from the 1990s through until now is that the sun is much the same as it has ever been for the majority of modern human civilised life and has contributed minor amounts to the observed changes of the past century; those changes primarily driven by human caused change to the insulation properties of the atmosphere.

  \1 Jack Eddy overcame this with a 1976 study that demonstrated that irregular variations in solar surface activity, a few centuries long, were connected with major climate shifts. The mechanism was uncertain, but plausible candidates emerged. The next crucial question was whether a rise in the Sun's activity could explain the global warming seen in the 20th century?

  By the 1990s, there was a tentative answer: minor solar variations could indeed have been partly responsible for some past fluctuations... but future warming from the rise in greenhouse gases far outweighed any solar effects.

~ https://history.aip.org/climate/solar.htm

  \2 Couldn't the Sun be the cause of global warming?

  If the Sun were to intensify its energy output then, yes, it would warm our world. Indeed, sunspot data indicate there was a small increase in the amount of incoming sunlight between the late 1800s and the mid-1900s that experts estimate contributed to at most up to 0.1°C of the 1.0°C (1.8°F) of warming observed since the pre-industrial era.

  However, there has been no significant net change in the Sun’s energy output from the late 1970s to the present, which is when we have observed the most rapid global warming.

~ https://www.climate.gov/news-features/climate-qa/couldnt-sun...

  \3 The Basics of Climate Change: https://royalsociety.org/news-resources/projects/climate-change-evidence-causes/basics-of-climate-change/