AGW proponents use subjective forcing models and unmeasured estimates of past solar activity to claim humans drive warming. A scientist’s (Larminat, 2023) reassessment finds the Sun can drive climate, equilibrium climate sensitivity (ECS, 2xCO2 + feedbacks) is 1.14°C, and human forcing is overestimated.
Because there have been no direct measurements of solar activity until the late 1970s, proponents of anthropogenic global warming (AGW) rely on “a high degree of (informed) subjectivity,” a “degree of belief that exists among [IPCC] lead authors,” and uncertain solar models and proxy-based assumptions to conclude the Sun has not had more than a negligible role in climate change (Larminat, 2023). This way it can be claimed that human activities, especially CO2 emissions, are predominantly or even solely responsible for modern warming.
However, because these climate models and numerical approximations are derivations of meteorological models designed to predict the weather, they are “questionable for validating the anthropogenic principle.”
When alternative estimates of past solar activity assume the Sun to have played a more substantial role in warming, and when efforts to “disappear” the Medieval Warm Period and Little Ice Age climate variations go unrealized, it can instead be shown that the anthropogenic impact on climate has been strongly overestimated (ECS = 1.14°C, not 2.5 to 4.0°C as claimed by the IPCC), and solar activity is the predominant driver of past and even modern warming.