The blue line below shows US temperature averaged at all GHCN HCN stations. The orange line shows the data released to the public by NCDC. They massively cool the past, to create the appearance of a non-existent warming trend. The thermometer data shows that the 1930’s Dust Bowl were much hotter than the present, but that doesn’t fit the agenda.
Measured data is here : Index of /pub/data/ghcn/daily/hcn/
NCDC data is here : Climate at a Glance | Time Series
We are at the 75th anniversary of Steinbeck’s “Grapes of Wrath” which chronicled the mass migration out the plains states, to escape the extreme heat and drought of the 1930’s.
The next graph shows the magnitude of the “adjustments” NCDC is performing. Given the well documented problems with Urban Heat Islands, the adjustments should be going the other way.
James Hansen wrote this in 1999, right before he erased the 1930’s heat.
Empirical evidence does not lend much support to the notion that climate is headed precipitately toward more extreme heat and drought. The drought of 1999 covered a smaller area than the 1988 drought, when the Mississippi almost dried up. And 1988 was a temporary inconvenience as compared with repeated droughts during the 1930s “Dust Bowl” that caused an exodus from the prairies, as chronicled in Steinbeck’s Grapes of Wrath.