The Myth About Record Temperatures
By Paul Homewood
We often hear that more and more record high temperatures are being set in the US. According to NCAR, who produced the above graph,
Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows. The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continue to climb.
"Climate change is making itself felt in terms of day-to-day weather in the United States," says Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR). "The ways these records are being broken show how our climate is already shifting."
In a previous analysis in Kansas, I showed that these claims of record temperatures were not all that they seemed. For instance there were 42 record daily highs at official stations claimed for Kansas in July 2011. These occurred in eight stations, but none of these were operational before 1939, and consequently had no data for the hot years in the 1930’s. It also turned out that all eight stations were airport based and two were both situated in the same city, Topeka!
A further concern is that the number of sites where these temperatures are measured has changed over the years, making comparisons pretty meaningless.
So, to put these record temperatures into perspective, let’s take a look at one particular station, Horton in Kansas. Yes, I know it is only one state. Nevertheless, it is reasonably representative of the US as a whole, with a warming trend of 0.08F/decade since 1895, so you would expect a lot of record temperatures to have been set in recent years.
Climate At A Glance
Annual 1901 – 2000 Average = 54.23 degF
Annual 1895 – 2011 Trend = 0.08 degF / Decade
Horton is also a good example because it is not airport based, has been at exactly the same location since 1893 and is a USHCN station. (USHCN sites are selected as being high quality ones).
Daily temperatures are available from the USHCN website, back to 1895, which I have used to establish the all time high temperatures for each day of the year, (maximums, not means by the way). I have also included “ties”.
For example, the highest maximum temperature recorded on 1st January was 63F in 1939. (In other words, I am not talking about records set at the time that have been exceeded since).
What does this analysis show?
The number of all time records set in the last decade are not only far, far less than the extremely hot 1930’s, but also less than many other periods, such as the 1980’s. The last 10 years, 2002-11, has seen 16 daily records. Bearing in mind that including “ties”, there are a total of 432 records, the norm for a decade should be 37. Clearly, nothing unusual is happening in Kansas.
Which brings us back to the NCAR graph at the top of the page. It of course begins in the 1950’s. Information is available to NCAR for the full US network back to at least 1895, so why have they not chosen to use anything prior to 1950? The answer, of course, is obvious – their claim “that greenhouse gases are causing increasing numbers of daily high temperatures” would rather fall to pieces if the full record was presented.
According to their website, NCAR (National Center for Atmospheric Research) are a “federally funded research and development center sponsored by the National Science Foundation and devoted to service, research and education in the atmospheric and related sciences. Significant additional support is provided by other U.S. government agencies, other national governments, and the private sector.
If taxpayers are funding this research, they are entitled to be told the whole truth, not just the bit that supports a preconceived message. They call themselves scientists, but real scientists do not behave in this dishonest way.
We have, of course, seen the same sort of mendacious behaviour from the UK Met Office in their presentation of long term CET temperatures, which conveniently omits the period during the 1730’s when temperatures were as high as now. Perhaps it is catching.
The full list of daily highs at Horton can be seen here. (Warning – may be a long file to download!)
And another footnote!!
Reader Don B has kindly pointed me to an article for ICECAP by Dr Keen of the University of Colorado in 2009, which comes to similar conclusions as mine across the whole of CONUS. His graph is reproduced below, showing state all time records (i.e. one per state, rather than daily records).