Wood Romances

I see many contrarians using the Hadley Central England Temperature record (HadCET) temperature record in an attempt to say that "modest warming" has been happening for 300 years, long before CO2 could be to blame, suggesting that continued warming in recent decades can't be attributable to CO2. Much of this rhetoric depends on dishonesty for at three reasons:  HadCET is a local temperature record for Central England. It's not a good indicator of global temperatures. There were no daily means available between 1659 and 1772, only monthly means. These means are not terribly reliable compared to modern temperature records, and they depend on estimates and historical diaries, instead of daily readings. From 1772 to 1878, HadCET only records daily means but lacks Tmax and Tmin data. HadCET is only directly comparable to modern temperature records in 1878. Most annalists consider HadCET to be moderately reliable following 1772, and we should treat the data prior to 1772 wi...

One of the main reasons why most of our GMST datasets go back only to 1850 is that we don't have enough SST measurements prior to 1850 to calculate GMST anomalies with a confidence interval small enough to be useful. However, ships did record surface air temperatures at least back into the 1780s. Recently the Global Surface Air Temperature project ( GloSAT ) digitized records of marine air temperatures taken on ships to form the GloSAT dataset, which contains near surface air temperatures back to 1781. Ed Hawkins, who worked on the project, has a good post describing the results of the project. The GloSAT database only goes to 2021, so I have included HadCRUT5 so that you can see the close agreement between the two. I find it interesting that the GloSAT dataset captures a little more variability in GMAT in the late 19th century, though trends are not that different between the two. The 95% confidence intervals for annual means are less than 0.3°C for most of the 18th century, exce...