The Deeper we delve into the chicanery of climate science, the more guano seems to float to the surface. In recent days serious questions are being asked about the significant global cooling that took place in the 1970 ... the significant cooling that was so severe the northern hemisphere actually warmed.
First, there is the old record:
Human emissions of carbon dioxide began a sharp rise from 1945. But, temperatures, it seems, may have plummeted over half the globe during the next few decades. Just how large or how insignificant was that decline?
Frank Lansner has found an historical graph of northern hemisphere temperatures from the mid 70’s, and it shows a serious decline in temperatures from 1940 to 1975. It’s a decline so large that it wipes out the gains made in the first half of the century, and brings temperatures right back to what they were circa 1910. The graph was not peer reviewed, but presumably it was based on the best information available at the time. In any case, if all the global records are not available to check, it’s impossible to know how accurate or not this graph is. The decline apparently recorded was a whopping 0.5°C.
But, three decades later, by the time Brohan and the CRU graphed temperatures in 2006 from the same old time period, the data had been adjusted (surprise), so that what was a fall of 0.5°C had become just a drop of 0.15°C. Seventy percent of the cooling was gone.
It's interesting, that once one stirs the pot,
more lumps pop to the surface: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 rabocore data.
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.
... so far it's all just questions ... but as we learned with the CRU and NASA, where there's smoke, there's guano.