This is crossposted from the Abrupt Sea Level Rise Thread where there was some debate over warming from preindustrial.
The graph below (source:
http://berkeleyearth.org/2019-temperatures/) shows 6 temperature data sets: Berkeley Earth’s, NASA’s GISTEMP, NOAA’s GlobalTemp, the UK’s HadCRUT, Cowtan & Way, and ECMWF's.
Note that the anomaly on the graph is compared to the 1981-2010 baseline.
Note that the lowest temperature anomaly for 2019 is ~0.44C in the HadCRUT dataset (dark blue line).
Note that as pasted below (taken from the CopernicusEU website where the ECMWF data is posted) 0.63°C (±0.06ºC) should be added to this value to relate it to the pre-industrial level defined in the IPCC Special Report on “Global Warming of 1.5°C”.
Using this method for the HadCRUT dataset we get 0.44 + 0.63 = 1.07 = ~1.1C above the preindustrial baseline.
Note that the highest temperature anomaly for 2019 is from the ECMWF data set, which gives a corrected value of 1.22 or ~1.2C above the pre-industrial baseline (as posted below from their website).
So all datasets place 2019 above 1C of warming over preindustrial, with the median being ~1.15C above preindustrial, though the mean would be higher since HadCRUT is the most anomalous from the other datasets.
https://climate.copernicus.eu/surface-air-temperature-december-2019"Averaging over twelve-month periods smooths out the shorter-term variations. Globally, the calendar year 2019 was 0.59°C warmer than the 1981-2010 average. The warmest twelve-month period was from October 2015 to September 2016, with a temperature 0.66°C above average. 2016 is the warmest calendar year on record, with a global temperature 0.63°C above that for 1981-2010. 2019 has become the second warmest calendar year in this data record. The third warmest calendar year, 2017, had a temperature 0.54°C above average.
0.63°C (±0.06ºC) should be added to these values to relate recent global temperatures to the pre-industrial level defined in the IPCC Special Report on “Global Warming of 1.5°C”. Using the central estimate and rounding to one decimal place, the average temperature for 2019 is 1.2°C above the level."