Has the Sun’s Role in Climate Change Been Trivialized?
August 09, 2021
Central to the narrative that climate change comes largely from human emissions of greenhouse gases is the assertion that the sun plays almost no role at all. According to its Fifth Assessment Report, the IPCC (Intergovernmental Panel on Climate Change) attributes no more than a few percent of total global warming to the sun’s influence.
But the exact amount of the solar contribution to global warming is critically dependent on how much the sun’s heat and light output, known technically as the TSI (total solar irradiance), has varied since the 19th century. According to an international team of scientists in a recently published paper, different estimates of the TSI lead to different conclusions about global warming – ranging from the sun making a trivial contribution, which backs up the IPCC claim that recent warming is mostly human-caused, to the opposite conclusion that global warming is mostly natural and due to changes in solar activity.
How can there be such a wide discrepancy between these two positions? Over the approximately 11-year solar cycle, the TSI varies by only a tenth of one percent. However, long-term fluctuations in the sun’s internal magnetic field cause the baseline TSI to vary over decades and centuries.
https://www.scienceunderattack.com/blog/2021/8/9/has-the-suns-role-in-climate-change-been-trivialized-83
