Jo Nova has an interesting and detailed post guest post by Bob Fernley-Jones on heavily homogenised rural sites in Australia by the Australian BOM.
I did a quick comment that was somewhat lacking in clarity. This post is to clarify my points.
In the post Bob Fernley-Jones stated
The focus of this study has been on rural stations having long records, mainly because the BoM homogenisation process has greatest relevance the older the data is.
Venema et al. 2012 stated (Italics mine)
The most commonly used method to detect and remove the effects of artificial changes is the relative homogenization approach, which assumes that nearby stations are exposed to almost the same climate signal and that thus the differences between nearby stations can be utilized to detect inhomogeneities (Conrad and Pollak, 1950). In relative homogeneity testing, a candidate time series is compared to multiple surrounding stations either in a pairwise fashion or to a single composite reference time series computed for multiple nearby stations.
This assumption of nearby temperature stations being exposed to same climate signal is standard practice. Victor Venema, (who has his own blog) is a leading academic expert on temperature homogenisation. However, there are extreme examples where this assumption does not hold. One example is at the end of the 1960s in much of Paraguay where average temperatures fell by one degree. As this was not replicated in the surrounding area both GISTEMP and Berkeley Earth homogenisations eliminated this anomaly. This was despite using very different homogenisation techniques. My analysis is here.
On a wider scale take a look at the GISTEMP land surface temperature anomaly map for 2014 against 1976-2010. (obtained from here)
Despite been homogenised and smoothed it is clear that trends are different. Over much of North America there was cooling, bucking the global trend. What this suggests to me is that the greater the distance between weather stations the greater the likelihood that the climate signals will be different. Most importantly for temperature anomaly calculations, over the twentieth century the number of weather stations increased dramatically. So it is more likely homogenisation will end up smoothing out local and sub-regional variations in temperature trends in the early twentieth century than in the later period. This is testable.
Why should this problem occur with expert scientists? Are they super beings who know the real temperature data, but have manufactured some falsehood? I think it is something much more prosaic. Those who work at the Australian BOM believe that the recent warming is human caused. In fact they believe that more than 100% of warming is human caused. When looking at outlier data records, or records that show inconsistencies there is a very human bias. Each time the data is reprocessed they find new inconsistencies, having previously corrected the data.
Posted by manicbeancounter on 17/09/2015
The BBC has rightly highlighted the 70.7% rise in Islamophobic crime in the 12 months to July 2015 compared to the previous 12 months to 718 instances. Any such jump in crime rates should be taken seriously and tackled. To be attacked for one’s religion, including being punched and having dog faeces smeared on one’s head is repulsive. However, according to the Metropolitan Police Crime Figures it is still less than 0.1% of total 720,939 crimes reported, and still a fraction of the crimes of Rape (5,300) and Robbery against the Person (20,300).
Raheem Kassam of Breitbart has a point when he states that there has been a 93.4% rise in Anti-Semitic crimes to 499 in the same period. He then points out that a Jew is a number of times more likely to be a victim of a religious hate crime in London than a Muslim. However, he fluffs the figures, as he makes a comparison between London crime figures and total numbers of adherents of each religion in the UK. Yet the Greater London Authority has a Datastore with the population by borough, along with the proportion of each religious group. The Metropolitan Police Crime Figures are also by borough. From this I have looked at the ten worst boroughs for Islamophobic and Anti-Semitic Hate Crime, which I have appended below.
- The London Borough with the highest number of reported Islamophobic hate crimes was Westminster with 54 reported in the 12 months ended July 2015, but relative to the number of Muslims living in the borough, Islington had the highest rate with 3.0 hate crimes per 1,000 Muslims.
- Overall in London reported 718 in Islamophobic hate crimes reported was equivalent to 0.6 per 1,000 Muslims.
- The London Borough with the highest number of reported Anti-Semitic hate crimes was Hackney with 122 reported in the 12 months ended July 2015, but relative to the number of Jews living in the borough, Tower Hamlets had the highest rate with 10.6 hate crimes per 1,000 Jews.
- Overall in London reported 499 in Anti-Semitic hate crimes reported was equivalent to 3.2 per 1,000 Jews.
- A Jew in London is therefore more than five times more likely to be the victim of a religious hate crime than a Muslim. In the London Borough of Tower Hamlets the Jew is over thirty times more likely to be a victim than a Muslim. Even Islington, proportionately the worst borough for Muslims, the Jew is still more than twice as likely to be a victim as the Muslim.
As a final note, late yesterday evening there was an extreme Anti-Semitic attack in North Manchester. Four young men were brutally attacked at a Metrolink Station. The youngest, for a period, was into a coma according to The Jewish Chronicle. I join in the prayers for his speedy and full recovery.
Posted by manicbeancounter on 07/09/2015