Shrinking Stevenson Screens cause global warming (and peeling paint, long grass…)

The Australian BOM has lost its way

Australia’s Bureau of Meteorology is paid more than a million dollars a day, and the planet is under seige, yet the paint is peeling off some Australian thermometer screens, the grass is long, and wasps are nesting in them. What once were large 230 litre wooden boxes have shrunk to 60 litres and are now even turning to plastic. The old glass thermometers are being replaced with electronic gear that can record a burst of hot air — yet somehow those freak high spikes are supposed to be comparable to temperatures recorded 100 years ago by slow glass thermometers.

Old larger boxes protected thermometers from sudden changes in air temperature.

Left: Len Walker with a 230L screen in 1940. Right: Blair Trewin with a modern 60L Stevenson screen.

Possibly the hardest thing to explain is that even though the BOM collected comparison data on the different types of thermometers, which might help to assess new versus old, they routinely throw the data away. Compounding that, the metadata on sites is incomplete, missing, lacking in documentation. Giant six lane highways are built next to equipment sites but not recorded. There is a huge […]