Long term stations show NO WARMING before “adjustments”
Figure 3: Temperature trends and station counts for all US stations in GISS reporting
continuously, that is containing at least one monthly data point for each year from
1900 to 2000. The slope for the rural stations (335 total) is -0.00073 deg/year,
and for the other stations (278 total) -0.00069 deg/year. The monthly data point
coverage is above 90% throughout except for the very first few year For the whole
Frank Lansner has done some excellent follow-up on the missing “decline” in temperatures
from 1940 to 1975, and things get even more interesting. Recall that the original
“hide the decline” statement comes from the ClimateGate emails and refers to “hiding”
the tree ring data that shows a decline in temperatures after 1960. It’s known as
the “divergence problem” because tree rings diverge from the measured temperatures.
But Frank shows that the peer reviewed data supports the original graphs and that
measured temperature did decline from 1960 onwards, sharply. But in the GISS version
of that time-period, temperatures from the cold 1970′s period were repeatedly “adjusted”
years after the event, and progressively got warmer.
The most mysterious period is from 1958 to 1978, when a steep 0.3C decline that was
initially recorded in the Northern Hemisphere. Years later that was reduced so far
it became a mild warming, against the detailed corroborating evidence from raobcore
Raobcore measurements are balloon measures. They started in 1958, twenty years before
satellites. But when satellites began, the two different methods tie together very
neatly–telling us that both of them are accurate, reliable tools.
You can see how similar the data from both methods is:
So what do the raobcores tell us about the period before satellites started recording
temperatures? They make it clear that temperatures fell quickly from 1960-1970.
The decline in the original graph in National Geographic in 1976 is apparently backed
up by highly accurate balloon data, and was based on peer reviewed data: Budyko
1969 and Angell and Korshover (1975). These two sets overlap from 1958 to 1960, and
correlate well, so stitching them together is reasonable thing to do and it doesn’t
make much difference which year is chosen from the overlap period (indeed any other
choice makes the decline slightly steeper).