- Recently, @berkeleyearth.org expanded our temperature database by integrating the HCLIM data set. nature.com/articles/s41... The additional data rescued by HCLIM helps improve early reconstructions, but doesn't fundamentally change the large uncertainties due to sparse sampling. 1/
- Though accurate liquid-in-glass thermometers were invented in early 18th century, weather monitoring remained sparse for the next ~150 years. 2/Dec 2, 2025 12:08
- In very early instrumental reconstructions (pre-1850), one is often only sampling a small area, e.g. ~15% of the Earth. Using modern weather patterns, one them estimates how different the other ~85% is likely to be from the part you can see, giving rise to an uncertainty. 3/
- Even with large uncertainties, early instrumental reconstructions can be useful in probing climate states that are different from what we experience today. bsky.app/profile/raro... 4/
- The best way to reduce those large uncertainties would be to bring in more historical data for better global coverage. Data rescue and digitizations efforts like HCLIM, can play a big role in trying to make more early weather data available. 5/
- Often early weather data exists only on paper records in some obscure government or university storage facility. Finding them and digitizing them for further use helps to open up new insights and data that would not be available in other ways. 6/6
