Sources

Every source cited on this site, with its tier and an archived copy. Tier 1 is primary data; tier 2 is a reputable aggregator that names its primary source.

• Tier 1GISS Surface Temperature Analysis (GISTEMP), version 4. GISTEMP Team, NASA Goddard Institute for Space Studies, 2026.Archived copy of GISS Surface Temperature Analysis (GISTEMP), version 4
• Tier 1Chapter 2: Changing State of the Climate System. Gulev, S.K., P.W. Thorne, J. Ahn et al. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the IPCC. Cambridge University Press, 2021.Archived copy of Chapter 2: Changing State of the Climate System
• Tier 1Summary for Policymakers. IPCC. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the IPCC. Cambridge University Press, pp. 3–32, 2021.Archived copy of Summary for Policymakers
• Tier 1A NASA GISTEMPv4 observational uncertainty ensemble. Lenssen, N., G.A. Schmidt, M. Hendrickson, P. Jacobs, M. Menne and R. Ruedy. Journal of Geophysical Research: Atmospheres, 129(17), e2023JD040179, 2024.Archived copy of A NASA GISTEMPv4 observational uncertainty ensemble
• Tier 1Mauna Loa CO₂ monthly mean data. NOAA Global Monitoring Laboratory and Scripps Institution of Oceanography (Xin Lan, NOAA GML; Ralph Keeling, Scripps), 2026.Archived copy of Mauna Loa CO₂ monthly mean data