Please see [1], which has before-and-after plots (page 18) that appear to match up with the differences you're seeing and describes why those adjustments were m

Please see [1], which has before-and-after plots (page 18) that appear to match up with the differences you're seeing and describes why those adjustments were made (section 4, on page 3). For example, it fixes biases that resulted from different time-of-day for measurements, stations moving their thermometer locations over time, and a couple others. One thing that doesn't perfectly match up is that the peak in the 1930s of the before-adjustment plot in [1] doesn't go quite as high as Fig 6 of the 1999 paper, but it does seem to match Plate A2, so I would assume it is a difference of using calendar years vs meteorological years (section A2 of the 1999 paper). Regarding your broader point: I think skepticism is great; asking questions is how we learn new things, after all. But it's not so great to assume that climate science must be wrong (or a political narrative) just because you found something that doesn't immediately make sense. Often it simply means climate scientists know something we don't. Also, since you mentioned concern about financial conflicts of interest, I'd encourage you to consider that the anti-climate-change narrative is just as (if not more) susceptible to those. Fossil fuels are big business. [1] https://pubs.giss.nasa.gov/docs/2001/2001_Hansen_ha02300a.pdf https://pubs.giss.nasa.gov/docs/2001/2001_Hansen_ha02300a.pd...