The percentage contribution to global warming over the past 50-75 years is shown in two categories, human causes (left) and natural causes (right), from various peer-reviewed studies (colors). The studies used a wide range of independent methods, and provide multiple lines of evidence that humans are by far the dominant cause of recent global warming. Most studies showed that recent natural contributions have been zero or slightly in the cooling direction, thereby masking part of the human contribution and in some cases causing it to exceed 100% of the total warming.
The studies are Tett et al. 2000 (T00, dark blue), Meehl et al. 2004 (M04, red), Stone et al. 2007 (S07, green), Lean and Rind 2008 (LR08, purple), Huber and Knutti 2011 (HK11, light blue), Gillett et al. 2012 (G12, orange), Wigley and Santer 2012 (WG12, dark green), Jones et al. 2013 (J13, pink), IPCC AR5 (IPCC, light green), Ribes et al. 2016 (R16, dark blue), and Gillett et al. 2021 (G21, yellow). The numbers in this summary are best estimates from each study; uncertainty ranges can be found in the original research.
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