HN user
Something similar seems to have happened previously to MIT and Harvard. (https://www.nytimes.com/2015/02/13/education/harvard-and-mit...).
Has that impacted OCW availability? I was noticing a lack of newer OCW material, but I have no data to substantiate that perception.
Here is an analysis from a data-driven organization dedicated to listing, understanding and reducing biases in science records. They have covered the National Climate Data Center data (which apparently GISS uses).
http://berkeleyearth.org/understanding-adjustments-temperatu...
Edit: this discussion does focus on the U.S. network, where some of the articles you listed referred to data from Africa and South America, but assumedly the corrective techniques are similar.