German experts Sebastian Lüning and Fritz Vahrenholt tell at their Die kalte Sonne site us why the 2013 Cowtan and Way paper has proven to be a flop.
Failed spectacularly: Arctic data hole theory for the warming pause collapses
By Sebastian Lüning and Fritz Vahrenholt
(Translated, edited by P Gosselin)
For quite some time climate scientists have been desperately seeking an explanation for the unexpected warming pause. On November 15, 2013 in the Süddeutsche Zeitung Christopher Schrader declared that the solution had been found: There was no pause; the data had only been missing from the Arctic.
Climate change without pause
According to the data, the earth had not warmed over the past years. However, this impression is likely related to missing data from the Arctic. And there the temperature appears to have risen much more strongly than the global average.[…] These [temperature] measurements have large holes: Approximately one sixth of the earth is not covered. Foremost in the Arctic there are not enough thermometers. But according to all signs it is warming considerably more quickly than the rest of the planet. An English and a Canadian scientist now show how this hole can be closed up with estimated values and how the supposed warming pause practically disappears. Kevin Cowtan of the University of York and Robert Way of the University of Ottawa refer to satellite data. […] Thus ultimately Cowtan and Way arrived at the result that the Arctic warmed eight times faster than the rest of the planet. Before that it had been thought that it was warming three times faster.”
Unfortunately Schrader did not mention that the two scientists were climate activists who were close to the IPCC-friendly Internet platform Skeptical Science. Yet, he still was unable to let slip out a couple of critical words about the two authors:
However the process is too complicated in order to find widespread recognition. Doubt will be stirred up among many because both authors have no name in climate science. Kevin Cowtan is a theoretical physicist and computer specialist at the Department of Chemistry at his University. Robert Way is still busy writing his doctorate dissertation.
It’s been a full year since the appearance of the dubious paper by Cowtan and Way, one that was highly praised by Stefan Rahmstorf. So just how was this pioneering paper received by the science community? On January 29, 2015 the answer from their colleagues appeared in the Geophysical Research Letters. The dodgy Arctic data fill-in model has failed spectacularly and has been soundly rejected. The answer to the pause is not to be found in the Arctic as Cowtan and Way suspected, rather it is to be found at the lower geographical geographical latitudes, as a team of scientists of the Danish Meteorological Institute in Copenhagen led by Hans Gleisner reports in a new publication. What follows is the paper’s abstract:
Recent global warming hiatus dominated by low-latitude temperature trends in surface and troposphere data
Over the last 15 years, global mean surface temperatures exhibit only weak trends. Recent studies have attempted to attribute this so called temperature hiatus to several causes, amongst them incomplete sampling of the rapidly warming Arctic region. We here examine zonal mean temperature trends in satellite-based tropospheric data sets (based on data from (Advanced) Microwave Sounding Unit and Global Navigation Satellite System Radio Occultation instruments) and in global surface temperatures (HadCRUT4). Omission of successively larger polar regions from the global mean temperature calculations, in both tropospheric and surface data sets, shows that data gaps at high latitudes cannot explain the observed differences between the hiatus and the prehiatus period. Instead, the dominating causes of the global temperature hiatus are found at low latitudes. The combined use of several independent data sets, representing completely different measurement techniques and sampling characteristics, strengthens the conclusions.