Humor4u

Above image shows NOAA Land+Ocean monthly temperature anomalies from the 20th century average. A trend has been added, based on the Jan.1880-Jan.2020 data. The trend shows that data in the early 1900s were some 0.28°C below the 20th century average. Adjustment When using a 1750 baseline, the data need to be adjusted even more than that 0.28°C, since it was even colder in 1750. The total baseline adjustment may well be 0.58°C, as discussed in an earlier post . Furthermore, ocean data in above image are sea surface temperatures. To reflect air temperatures, a further 0.1°C adjustment is applied. Finally, an extra 0.1°C adjustment is applied to reflect higher polar temperatures (as opposed to leaving out missing data). Altogether, this adds up to a 0.78°C adjustment, which implies that the temperature in January 2020 was 1.92°C above pre-industrial. Which trend is most applicable? How much and how fast could temperatures keep rising? That question looks even more important than this 0...

As illustrated by above map, Arctic heating is accelerating, with temperatures showing up in the Arctic that are up to 4.41°C hotter than the average global temperature during 1880-1920. The image below shows two plots. On the left-hand side is the temperature plot associated with above map, had a monthly mean been selected. To smooth the data, a 4-year running mean was chosen, and the plot on the right-hand side shows the associated global mean anomalies. Note that, due to this smoothing, only data from 1882 to August 2017 are displayed in the plot of the right-hand side. It is appropriate to adjust the data by 0.5°C, as follows: An adjustment of 0.3°C to reflect a pre-industrial baseline (heating occurred due to people's emissions before 1880-1920); An adjustment of 0.1°C to reflect air temperatures over oceans (as opposed to sea surface temperatures); An adjustment of 0.1°C to better include polar temperatures (the top and bottom of the image at the top shows large polar ar...