Friday, August 28, 2015
Another Study Shows Global Warming "Pause" Never Happened
Yet another climate research paper has disclosed that there really was no global warming "hiatus" or pause. It was a matter of inconsistent data treatment, particularly in processing sea surface temperatures - especially as measured by buoys. First reported by the Intergovernmental Panel on Climate Change (IPCC) in 2013, the claim resulted from an erroneous interpretation resulting from a disproportionate use of buoys the past several decades. As is now known, these buoys tend to give cooler readings than measurements taken from ships. This was noted by Thomas Karl, Director of the National Centers for Environmental Information of the National Oceanic and Atmospheric Administration. (NOAA) and lead author of the recent paper which appeared in the journal Science.
This error was likely compounded in conjunction with the misinterpretation of Hadley UK Center future projections on climate that I've already discussed at length, e.g.
I would even venture to say that the preponderance of false judgment by too many (mainly conservatives like George Will eager for a counter poise) resulted from the misinterpretation of data in that cited Nature paper by Noel Keenlyside et al from 2008. But the new results independently show the warming pause to be bogus.
As Karl noted, quoted in Eos Transactions - Earth & Space Science (July 1):
"The biggest takeaway is there is no slowdown in global warming".
Indeed, he added that warming the past fifteen years is the "strongest it's been since the latter half of the 20th century". Putting an exclamation point on that, July this year has been the hottest July since records were initiated.
A good summary of the paper may be accessed at:
Why the measurement difficulty? Well, because the data gathering and process of analysis are inherently complex. In order to achieve such a measurement as how Earth's average global temperature is increasing, there's a lot of "sausage making". First, scientists must combine thousands of measurements from Earth's surface, taken by land instruments, ships. buoys and orbital satellites.
Second, each of these has its own random errors, all of which must be identified. Not only must researchers comb through the data to eliminate these errors, they must also correct for any differences in how each type of instrument measures temperature.
Thus, the authors of the Science paper had to dig into NOAA's global surface temperature analysis data to examine how sea surface temperatures (SSTs) were being measured. SSTs are measured in various ways:
- collecting ocean water in a bucket and measuring its temperature directly
- measuring the temperature of water taken in by a ship engine as a coolant
- using floating buoys moored in the various oceans
Each technique records slightly different temperatures in the same region so scientists have to adjust the data. In the past couple decades the number of buoys has increased - adding 15% more coverage to the ocean. But because buoys tend to read colder temperatures than ships at the same locations, a measurement bias is introduced which must be corrected for. This was the primary task set out by Karl et al. They corrected for the bias by adding 0.12C to each buoy temperature.
By then combining the ocean data with improved calculations of air temperatures over land around the world, Karl and colleagues found that overall global surface warming over 2000-14 was 0.116C per decade or more than twice the estimated 0.039C starting in 1998 that the IPCC had reported.
Over and above all of this, as noted in the Sci-Am link below, from a statistical perspective:
"The pause does not actually exist, since observations over 15 years are not significant enough to be called a climate trend."
But by then the erroneous take had "jumped the shark", as it were, and the conservo media was blind to everything else including the inevitable corrections!