It is the 30-year moving regression of Earth's temperature increase or decrease per year. It indicates the speed at which the Earth is warming up (red line) or cooling down (blue line), whereby positive higher values indicate faster warming and negative lower values indicate faster cooling. We use a 30-year moving regression because climate is about long-term weather patterns, typically averaged over 30 years.
The Rate of Temperature Change is a critical metric because it shows how fast global warming is happening.
Temperature change in degree Celsius (°C) or degree Fahrenheit (°F) per yearWikipedia: Degree Celsius
This chart focuses on the speed of the warming periods and cooling periods after 1850. Before 1920 there were periods of warming and cooling and they were relatively slow. After 1920 the change of temperature accelerated significantly, which you can see in the height of the second red hill. The following small blue area represents the slowdown and cooling period during the global dimming. After global dimming and 1975 the temperature rise became even faster than before and there have been no more cooling periods since.
Read more about details of Yearly Average Temperature and global dimming atYearly Average Temperature Anomaly
For values since 1850 we primarily use data from the IGCC, which is an average of four sources: HadCRUT5, NOAAGlobalTemp, Berkeley Earth and Kadow et al.. The IGCC data updates yearly, to estimate warming for the current year the latest updates from sources are used directly. This data is gathered using a huge number of weather stations on land, ships, buoys and more.
For the years leading up to 1850 we use PAGES2k Consortium reconstruction data. It is based on models where temperatures are reconstructed from proxies. Proxy analysis has higher uncertainty, and we display the smoothed set to highlight the longer-term fluctuations.
This value is a 30-year moving regression of temperature. We use a 30-year moving regression because climate is about long-term weather patterns, typically averaged over 30 years. A moving regression is a calculation used to analyze data points by creating a series of linear trendlines of different subsets of the full data set.Wikipedia: Moving regression
IGCCCredits: Chris Smith, Tristram Walsh, Alex Borger, Piers Forster, Nathan Gillett, Mathias Hauser, Willam Lamb, Robin Lamboll, Matthew Palmer, Aurélien Ribes, Dominik Schumacher, Sonia Seneviratne, Blair Trewin, & Karina von Schuckmann. (2023). Indicators of Global Climate Change 2022 (v2023.06.02). Zenodo. https://doi.org/10.5281/zenodo.8000192Update cycle: yearlyDelay: up to a year
HadCRUT5Credits: Morice, C.P., J.J. Kennedy, N.A. Rayner, J.P. Winn, E. Hogan, R.E. Killick, R.J.H. Dunn, T.J. Osborn, P.D. Jones and I.R. Simpson (in press) An updated assessment of near-surface temperature change from 1850: the HadCRUT5 dataset. Journal of Geophysical Research (Atmospheres) doi:10.1029/2019JD032361Update cycle: monthlyDelay: Less than 1 month
NOAA Global Temp. v5.1Credits: R. S. Vose, B. Huang, X. Yin, D. Arndt, D. R. Easterling, J. H. Lawrimore, M. J. Menne, A. Sanchez-Lugo, and H. M. Zhang (2022): NOAA Global Surface Temperature Dataset (NOAAGlobalTemp), Version 5.1 Gridded. NOAA National Centers for Environmental Information. doi.org/10.25921/2tj4-0e21.Update cycle: monthlyDelay: Less than 1 month
Temperature DataCredits: Rohde, R. A. and Hausfather, Z.: The Berkeley Earth Land/Ocean Temperature Record, Earth Syst. Sci. Data, 12, 3469–3479, https://doi.org/10.5194/essd-12-3469-2020, 2020.Update cycle: monthlyDelay: ~ 1 to 4 month
Kadow et al.Credits: Kadow, C., Hall, D.M. & Ulbrich, U. Artificial intelligence reconstructs missing climate information. Nat. Geosci. 13, 408–413 (2020). https://doi.org/10.1038/s41561-020-0582-5
PAGES2k Common Era Surface Temperature ReconstructionsCredits: PAGES2k Consortium: Raphael Neukom, Luis A. Barboza, Michael P. Erb, Feng Shi, Julien Emile-Geay, Michael N. Evans, Jörg Franke, Darrell S. Kaufman, Lucie Lücke, Kira Rehfeld, Andrew Schurer,Feng Zhu,Stefan Brönnimann, Gregory J. Hakim, Benjamin J. Henley, Fredrik Charpentier Ljungqvist, Nicholas McKay, Veronika Valler, Lucien von Gunten. 2019. Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era. Nature Geoscience, 12. doi: 10.1038/s41561-019-0400-0. Data accessed on May 4. 2022