claim: Based on the increase of solar activity during the twentieth century, it should account for between half to two-thirds of all climate change
evidence: Fossil fuel era [edit]The link between recent solar activity and climate has been quantified and is not a major driver of the warming that has occurred since early in the twentieth century.[24] Human-induced forcings are needed to reproduce the late-20th century warming.[25] Some studies associate solar cycle-driven irradiation increases with part of twentieth century warming.[26][27] [...] Benestad and Schmidt[45] concluded that "the most likely contribution from solar forcing a global warming is 7 ± 1% for the 20th century and is negligible for warming since 1980." This paper disagreed with Scafetta and West,[46] who claimed that solar variability has a significant effect on climate forcing. Based on correlations between specific climate and solar forcing reconstructions, they argued that a "realistic climate scenario is the one described by a large preindustrial secular variability (e.g., the paleoclimate temperature reconstruction by Moberg et al.)[47] with TSI experiencing low secular variability (as the one shown by Wang et al.).[48] Under this scenario, they claimed the Sun might have contributed 50% of the observed global warming since 1900.[49] Stott et al. estimated that the residual effects of the prolonged high solar activity during the last 30 years account for between 16% and 36% of warming from 1950 to 1999.[50]