Climate Delusions 1 – Karl et al 2015 propaganda

This is the first is a planned series of climate delusions. These are short pieces of where the climate alarmists are either deluding themselves, or deluding others, about the evidence to support the global warming hypothesis; the likely implications for changing the climate; the consequential implications of changing / changed climate; or associated policies to either mitigate or adapt to the harms. The delusion consists is I will make suggestions of ways to avoid the delusions.

Why is the Karl et al 2015 paper, Possible artifacts of data biases in the recent global surface warming hiatus proclaimed to be the pause-buster?

The concluding comments to the paper gives the following boast

Newly corrected and updated global surface temperature data from NOAA’s NCEI do not support the notion of a global warming “hiatus.”  …..there is no discernable (statistical or otherwise) decrease in the rate of warming between the second half of the 20th century and the first 15 years of the 21st century. Our new analysis now shows that the trend over the period 1950–1999, a time widely agreed as having significant anthropogenic global warming (1), is 0.113°C decade−1 , which is virtually indistinguishable from the trend over the period 2000–2014 (0.116°C decade−1 ). Even starting a trend calculation with 1998, the extremely warm El Niño year that is often used as the beginning of the “hiatus,” our global temperature trend (1998–2014) is 0.106°C decade−1 —and we know that is an underestimate because of incomplete coverage over the Arctic. Indeed, according to our new analysis, the IPCC’s statement of 2 years ago—that the global surface temperature “has shown a much smaller increasing linear trend over the past 15 years than over the past 30 to 60 years”—is no longer valid.

An opinion piece in Science, Much-touted global warming pause never happened, basically repeats these claims.

In their paper, Karl’s team sums up the combined effect of additional land temperature stations, corrected commercial ship temperature data, and corrected ship-to-buoy calibrations. The group estimates that the world warmed at a rate of 0.086°C per decade between 1998 and 2012—more than twice the IPCC’s estimate of about 0.039°C per decade. The new estimate, the researchers note, is much closer to the rate of 0.113°C per decade estimated for 1950 to 1999. And for the period from 2000 to 2014, the new analysis suggests a warming rate of 0.116°C per decade—slightly higher than the 20th century rate. “What you see is that the slowdown just goes away,” Karl says.

The Skeptical Science Temperature trend data gives very similar results. 1950-1999 gives a linear trend of 0.113°C decade−1 against 0.112°C decade−1 and for 2000-2014 gives 0.097°C decade−1 against 0.116°C decade−1. There is no real sign if a slowdown,

However, looking at any temperature anomaly  chart, whether Karl. NASA Gistemp, or HADCRUT4, it is clear that the period 1950-1975 showed little or no warming, whilst the last quarter of the twentieth century show significant warming.  This is confirmed by the Sks trend calculator figures in Figure 1.

What can be clearly seen is the claim of no slowdown in the twenty-first century compared with previous years is dependent on the selection of the period. To repeat the Karl et. al concluding claim.

Indeed, according to our new analysis, the IPCC’s statement of 2 years ago—that the global surface temperature “has shown a much smaller increasing linear trend over the past 15 years than over the past 30 to 60 years”—is no longer valid.

The period 1976-2014 is in the middle of the range, and from the Sks temperature trend is .160. The trend is significantly higher than 0.097, so a slowdown has taken place. Any remotely competent peer review would have checked what is the most startling claim. The comparative figures from HADCRUT4 are shown in Figure 2.

With the HADCRUT4 temperature trend it is not so easy to claim that there is no significant slowdown. But the full claim in the Karl et al paper to be a pause-buster can only be made by a combination of recalculating the temperature anomaly figures and selection of the 1950-1999 period for comparing the twenty-first century warming. It is the latter part that makes the “pause-buster” claims a delusion.

Kevin Marshall

 

Warming Bias in Temperature Data due to Consensus Belief not Conspiracy

In a Cliscep article Science: One Damned Adjustment After Another? Geoff Chambers wrote:-

So is the theory of catastrophic climate change a conspiracy? According to the strict dictionary definition, it is, in that the people concerned clearly conferred together to do something wrong – namely introduce a consistent bias in the scientific research, and then cover it up.

This was in response to last the David Rose article in the Mail on Sunday, about claims the infamous the Karl et al 2015 breached America’s National Oceanic and Atmospheric Administration (NOAA) own rules on scientific intergrity.

I would counter this claim about conspiracy in respect of temperature records, even in the strict dictionary definition. Still less does it conform to a conspiracy theory in the sense of some group with a grasp of what they believe to be the real truth, act together to provide an alternative to that truth. or divert attention and resources away from that understanding of that truth. like an internet troll. A clue as to know why this is the case comes from on of the most notorious Climategate emails. Kevin Trenberth to Micheal Mann on Mon, 12 Oct 2009 and copied to most of the leading academics in the “team” (including Thomas R. Karl).

The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t. The CERES data published in the August BAMS 09 supplement on 2008 shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate.

It is the first sentence that was commonly quoted, but it is the last part is the most relevant for temperatures anomalies. There is inevitably a number of homogenisation runs to get a single set of anomalies. For example the Reykjavik temperature data was (a) adjusted by the Iceland Met office by standard procedures to allow for known locals biases (b) adjusted for GHCNv2 (the “raw data”) (c) adjusted again in GHCNv3 (d) homogenized by NASA to be included in Gistemp.

There are steps that I have missed. Certainly Gistemp homogenize the data quite frequently for new sets of data. As Paul Matthews notes, adjustments are unstable. Although one data set might on average be pretty much the same as previous ones, there will be quite large anomalies thrown out every time the algorithms are re-run for new data. What is more, due to the nature of the computer algorithms, there is no audit trail, therefore the adjustments are largely unexplainable with reference to the data before, let alone with reference to the original thermometer readings. So how does one know whether the adjustments are reasonable or not, except through a belief in how the results ought to look? In the case of the climatologists like Kevin Trenberth and Thomas R. Karl, variations that show warmer than the previous run will be more readily accepted as correct rather than variations that show cooler. That is, they will find reasons why a particular temperature data set now shows greater higher warming than before. but will reject as outliers results that show less warming than before. It is the same when choosing techniques, or adjusting for biases in the data. This is exacerbated when a number of different bodies with similar belief systems try to seek a consensus of results, like  Zeke Hausfather alludes to in his article at the CarbonBrief. Rather than verifying results in the real world, temperature data seeks to conform to the opinions of others with similar beliefs about the world.

Kevin Marshall