This is a reposting of the second of five responses I made regarding various aspects of Jim Steele's 1/7/15 WattsUpWithThat 'essay' - in light of Steele's recent comment, I think it's only fair to bring it up again.
Monday, January 26, 2015
Regarding the question of USHCN homogenization
In relation to my dialogue with Mr. Steele, the irony is that he relies on his interpretation of USHCN data to make his point that California is not experiencing any warming, yet he broadcasts contempt for USHCN homogenization methods and their models. What's up with that? I also have to wonder why he didn't respond to my emails requesting more details and share this information with me. In any event, I'll share the information I'm able to gather over the next days and weeks.
In the meantime, perhaps it would be good to bring all this back down to Earth and actual observations.
Mr. Steele's repeatedly claims it's the local that matters. But in truth any appreciation of the "local" is impossible without understanding how it fits into the global pattern. I hope the following video drives that message home (followed by 2014 NOAA, NASA videos and look at California temperatures):
Published on Nov 17, 2014
An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the atmosphere travels around the globe.
Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources. The simulation also illustrates differences in carbon dioxide levels in the northern and southern hemispheres and distinct swings in global carbon dioxide concentrations as the growth cycle of plants and trees changes with the seasons.
The carbon dioxide visualization was produced by a computer model called GEOS-5, created by scientists at NASA Goddard Space Flight Center’s Global Modeling and Assimilation Office.
The visualization is a product of a simulation called a “Nature Run.” The Nature Run ingests real data on atmospheric conditions and the emission of greenhouse gases and both natural and man-made particulates. The model is then left to run on its own and simulate the natural behavior of the Earth’s atmosphere. This Nature Run simulates January 2006 through December 2006.
While Goddard scientists worked with a “beta” version of the Nature Run internally for several years, they released this updated, improved version to the scientific community for the first time in the fall of 2014.
This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/goto?11719
Global Analysis - Annual 2014
NOAA's National Climatic Data Center (NCDC)
- The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880. The annually-averaged temperature was 0.69°C (1.24°F) above the 20th century average of 13.9°C (57.0°F), easily breaking the previous records of 2005 and 2010 by 0.04°C (0.07°F). This also marks the 38th consecutive year (since 1977) that the yearly global temperature was above average. Including 2014, 9 of the 10 warmest years in the 135-year period of record have occurred in the 21st century. 1998 currently ranks as the fourth warmest year on record.
- The 2014 global average ocean temperature was also record high, at 0.57°C (1.03°F) above the 20th century average of 16.1°C (60.9°F), breaking the previous records of 1998 and 2003 by 0.05°C (0.09°F). Notably, ENSO-neutral conditions were present during all of 2014.
- The 2014 global average land surface temperature was 1.00°C (1.80°F) above the 20th century average of 8.5°C (47.3°F), the fourth highest annual value on record.
- Precipitation measured at land-based stations around the globe was near average on balance for 2014, at 0.52 mm below the long-term average. However, as is typical, precipitation varied greatly from region to region. This is the third consecutive year with near-average global precipitation at land-based stations.
Oh and regarding Jim's claim that California hasn't 'really' been experiencing any warming - H/T to Mr. Steele for including this study in some footnotes. Why he ignores it is yet another question.
My conjecture is that creating confusion is exactly what his goal is.
California Tmax trend average broken into 11 regionals.
Doesn't add up to Mr. Steele's claim, now does it?
And that's from 1918 to 2006,
the scary part is 1970 to 2006 . . . and beyond.
Check out the study:
Eugene C. Cordero · Wittaya Kessomkiat · John Abatzoglou · Steven A. Mauget
Received: 28 August 2009 / Accepted: 4 November 2010 © Springer Science+Business Media B.V. 2011
Victor Venema at Variable Variability
put together a good reading list of articles that look into temperature adjustment:
Phil Plait at Bad Astronomy comment on the Telegraph piece: No, Adjusting Temperature Measurements Is Not a Scandal
John Timmer at Ars Technica is also fed up with being served the same story about some upward adjusted stations every year: Temperature data is not “the biggest scientific scandal ever” Do we have to go through this every year?
The astronomer behind And Then There's Physics writes why the removal of non-climatic effects makes sense. In the comments he talks about adjustments made to astronomical data. Probably every numerical observational discipline of science performs data processing to improve the accuracy of their analysis.
Steven Mosher, a climate "sceptic" who has studied the temperature record in detail and is no longer sceptical about that reminds of all the adjustments demanded by the "sceptics".
Nick Stokes, an Australian scientist, has a beautiful post that explains the small adjustments to the land surface temperature in more detail.
My two most recent posts were about some reasons for temperature trend biases: Temperature bias from the village heat island and Changes in screen design leading to temperature trend biases
You may also be interested in the posts on how homogenization methods work (Statistical homogenisation for dummies) and how they are validated (New article: Benchmarking homogenisation algorithms for monthly data)