This is the average surface temperature of the whole Earth over a full year. It is based on measurements taken by thousands of weather stations on land and sea.
The Yearly Average Temperature is a crucial metric because the change in the Earth’s average temperature causes major transformations to our planet. It puts the existence of many species – including humans – at risk.Wikipedia: Climate Change
The Yearly Average Temperature is directly related to the Yearly Average Temperature Anomaly. The shapes of the graphs are the exact same. The average temperature between 1850 and 1900 is about 13.80 °C (56.84 °F), which is the pre-industrial baseline at which the anomaly is zero. For example the average temperature in 2020 was 15.15 °C (59.27 °F), which is 1.35 °C (2.43 °F) above the pre-industrial baseline (anomaly).
Degree Celsius (°C) or degree Fahrenheit (°F) per yearWikipedia: Degree Celsius
The overall increase in temperature since 1850 is driven by human emissions of several greenhouse gases, like carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and others, which cause an increased greenhouse effect. We, humans, are still emitting more greenhouse gases and are causing more warming.CO2 Carbon Dioxide Dashboard
The average temperature started rising in the 1920s, however, during the 1945 to 1975 period, heavy atmospheric pollution caused by humans cooled the Earth by reflecting sunlight, a process known as global dimming. The cooling effect from global dimming was reduced significantly by several global efforts to reduce air pollution.Wikipedia: Global Dimming
Since the late 1970s there has been a steady and very rapid increase in temperature, with peaks in 2016 and 2020. The highest yearly average temperature so far was +15.16 °C (59.29 °F).Rate of Temperature Change
For a large part of the last 2000 years the global average temperature was around 14 °C (57.2 °F). The warming of the last 100 years, currently above 15 °C (59 °F), is very large and extremely fast compared to any temperature change in the long period before.
While the global temperature does change over time due to natural causes, human greenhouse gas emissions cause changes that really disrupt our planet. If we, humanity, reduce our greenhouse gas emissions, we can halt global warming.Wikipedia: Climate Change
For values since 1850 we primarily use Berkeley Earth and add data from NASA GISS when they have more recent values available. 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.Wikipedia: Proxy (Climate)
The value for the current year is actually the average for the last 12 months, for example in March we include values since the previous April. This approach allows us to include the latest data for a full year and avoids showing possibly misleading values when using shorter time periods.
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 month
Global mean temperature dataCredits: GISTEMP Team, 2022: GISS Surface Temperature Analysis (GISTEMP), version 4. NASA Goddard Institute for Space Studies. Dataset accessed 20YY-MM-DD at https://data.giss.nasa.gov/gistemp/. Lenssen, N., G. Schmidt, J. Hansen, M. Menne, A. Persin, R. Ruedy, and D. Zyss, 2019: Improvements in the GISTEMP uncertainty model. J. Geophys. Res. Atmos., 124, no. 12, 6307-6326, doi:10.1029/2018JD029522Update cycle: monthlyDelay: ~ 1 weeks
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