The third attempt to erase the global warming "hiatus"
The fact that the global temperature record was showing a "hiatus" (was not showing any rise) was first pointed out some time ago by the late Bob Carter. Scorn and contempt was heaped on him for his pains. Warmists said it was just a "blip". Not unreasonably, they pointed to previous hiatuses -- such as the long hiatus of 1945 to 1975 (30 years!) -- and noted that temperature rises re-started after that.
A 30 year temperature hiatus while CO2 levels were rising strongly did not seem to embarrass them, despite it being totally contrary to their theory. They just explained it away as due to "special" factors.
But as the current hiatus got longer and skeptics got increasingly irritating about it, they had to do something. And in the best Green/Left tradition, their first response was to lie. They started to declare that various years were warmest, warmer etc. We got such declarations annually. The fact of the matter is that the fluctuations in the 21st century were tiny, differences in hundredths of one degree only -- so were statistically non-significant and hence non-existent from a scientific point of view. But who cares about science when an ideology is at risk?
Riding differences so tiny must have got irritating however, at least to the scientists among Warmists. They knew about statistical significance so ignoring it was undoubtedly embarrassing.
Then Tom Karl of NOAA rode to the rescue. He made large "corrections" to the ocean temperature record and thus erased the hiatus. That attracted such a lot of criticism, including Congressional criticism, that even the Warmist establishment in the Fyfe paper eventually disowned it and reaffirmed that there was a 21st century temperature slowdown, which they again explained as due to "special" factors.
The next attack on the hiatus was by crowing about the unusually large temperature rise in 2015. It actually amounted to 13 hundredths of one degree. Exciting! That it was just the expected effect of the El Nino weather phenomenon was pooh-poohed. But it was ENTIRELY due to El Nino and other natural causes because CO2 levels did not rise in 2015
All the fun so far had been with the surface temperature record, always a slender reed to lean on. In the background was the pesky satellite record showing no warming trend at all.
There has been a slight reprieve from that glowering satellite record recently in that it now shows some rise in early 2016. El Nino has not run its course yet, however, so there is no reason to think that that rise is anything but an El Nino effect. Additionally, El Nino should be followed by La Nina, which brings cooling, so the record for 2016 is likely to rejoin the hiatus. So the Warmists know they can't crow too loudly.
So we come to the latest erasure attempt: by Carl Mears, proprietor of RSS, one of the satellite records. As he himself admits, he has been mightily irritated by people accusing his temperature record of supporting the climate skeptics. He has in fact been expressing irritation with that for quite some years. He has declared several times that he still supports Warmism despite what his own data show.
So he has finally devised a solution to his embarrassment. He has "adjusted" his data. He said his old data had errors in it and he has now corrected the errors, to show some warming -- a warming of 18 hundredths of one degree over nearly 20 years, no less! One hundredth of a degree per annum! If there had been errors in it, one wonders why he rode with the "erroneous" data for so long but let that be by the by.
And the explanation he gives for his adjustments is reasonable in principle, but, as always, the devil is in the details. And the details do contain devilry, as Roy Spencer has pointed out. Carl's adjustments were so bad in fact that the paper in which he described them was rejected as unpublishable by a major climate journal, eventually being accepted by a meteorological one.
So Warmists seem to be back where they were when they first heaped contumely on Bob Carter, saying that the hiatus is just a blip due to "special" factors and warming should resume "real soon now". That is faith, however, not science. Geologically, we are at the end of a warming period so cooling is in fact somewhat more likely. But nobody knows and nobody can know.
The fourth word in Seth Borenstein's article below amuses me: "may". Even faithful old Seth clearly had his doubts about how strong Carl's arguments are
Climate change doubters may have lost one of their key talking points: a particular satellite temperature dataset that had seemed to show no warming for the past 18 years.
The Remote Sensing System temperature data, promoted by many who reject mainstream climate science and especially most recently by Sen. Ted Cruz, now shows a slight warming of about 0.18 degrees Fahrenheit since 1998. Ground temperature measurements, which many scientists call more accurate, all show warming in the past 18 years.
"There are people that like to claim there was no warming; they really can't claim that anymore," said Carl Mears, the scientist who runs the Remote Sensing System temperature data tracking.
The change resulted from an adjustment Mears made to fix a nagging discrepancy in the data from 15 satellites.
The satellites are in a polar orbit, so they are supposed to go over the same place at about the same time as they circle from north to south pole. Some of the satellites drift a bit, which changes their afternoon and evening measurements ever so slightly. Some satellites had drift that made temperatures warmer, others cooler. Three satellites had thrusters and they stayed in the proper orbit so they provided guidance for adjustments.
Mears said he was "motivated by fixing these differences between the satellites. If the differences hadn't been there, I wouldn't have done the upgrade."
NASA chief climate scientist Gavin Schmidt and Andrew Dessler, a climate scientist at Texas A&M, said experts and studies had shown these problems that Mears adjusted and they both said those adjustments make sense and are well supported in a study in the American Meteorological Society's Journal of Climate.
The study refutes the idea of a pause in global warming, "but frankly common sense and looking at how Earth was responding over the past 18 years kind of makes this finding a 'duh' moment," wrote University of Georgia meteorology professor Marshall Shepherd.
Chip Knappenberger of the Cato Institute, who doesn't doubt that human-caused climate change is happening but does not agree with mainstream scientists who say the problem is enormous, said this shows "how messy the procedures are in putting the satellite data together."
The other major satellite temperature data set, run by University of Alabama Hunstville professor John Christy, shows slight warming after 1998. But if 1998 is included in the data, it sees no warming. But that should change with a warm 2016, Christy said. In fact, Christy used his measurements to determine that February 2016 was 1.5 degrees Fahrenheit above the average for the month — the largest such disparity for any month since records were first kept, in 1979.
As far as what this means for people claiming no warming, scientists don't expect them to change.
"I don't know what Cruz, et al., will do now," Dessler said in an email. "I think it will be increasingly difficult for them to claim that the satellite data show now warming, although it may be possible to say that it shows 'no significant warming.'"