Scientists worldwide, including those at leading American institutions, routinely correct station data for changes such as
shifts in station location, different elevation, different time of daily observation, different latitudes, and instrument changes over time.
NCDC uses two correction processes to remove inhomogeneities associated with factors unrelated to climate such as changes in observer practices, instrumentation, and changes
in station location and environment that have occurred through time.
Yet for 49 of the 84 meteorological stations that Jones et al. relied upon, the DOE / CAS Report states «station histories are not currently available» and «details regarding instrumentation, collection methods, changes
in station location or observing times... are not known».
d. For long - term climate records, particularly in rapidly changing nations such as China, changes
in station location are to be expected.