A Calm Beginning

 I looked at the website that reports the global satellite temperature data every month. I wasn't sure there would be an update yet, as it is 2 January, the day after New Year's Day, and a weekend day, but the new data were posted. December 2021 was 0.21 degrees C above the thirty year average the site is now comparing to. That is up from November, which was 0.08. 2021 as a year came in at 0.134, placing it 8th in the list of warmest years. Six of the seven that were warmer have been since 2010. The exception is 1998, which still comes in as the third warmest year, and is the basis of quite a number of people claiming that there has been no global warming since then, even though 2016 and then 2020 were warmer in the satellite data.

Last I looked, 2021 was expected to finish as maybe the sixth warmest year in other data sets. NOAA and Copernicus and the Japan Meteorological Agency all use data from surface level thermometers, looking not just at air temperature but ground and water at the surface as well, so their numbers are a little different. All these global temperature data sets show increasing temperatures over time. The satellite data have a linear regression slope of 0.14 degrees per decade, which is up over the last ten years or so from 0.12 degrees per decade. I don't know if that change is statistically significant. But the slope is, and is steeper than the longer data sets, which go back to the late 1800's. That could suggest that global warming is accelerating, which I understand some models predict. Or it could just be a difference in data due to source and local effects.

The new data are not a surprise. I expect 2022 will continue along the same general trend as the last few years. It is probably significant that December had an increased anomaly compared to November despite the La Nina conditions. I think 2021 is in the top two years for La Nina years, but not certain, and don't feel the need to check as I have no readership. Maybe the algorithms will correct me if I'm wrong.