"Yes, numbers of sunspots can vary by that much or even more on an 11-year cycle, but the sun’s output—the total amount of energy we get—is extremely stable and only changes by about 0.1 percent, even in extreme sunspot cycles like the one Zharkova is predicting."
So a tiny fraction in variation of solar output is insignificant, while a tiny fraction of temperature increase in Earth's atmosphere will cause an ecological calamity? I would point out that while 0.1 percent isn't a lot relative to the Sun's total energy output, it's still a hell of a lot when measured in degrees.