Much of the raw data behind the various datasets reporting the average temperature of the world are now available. So it is possible to look for strange patterns in the daily or monthly temperature data. The reported "average temperature of the world" is, ultimately, derived from these datasets by various corrections, normalisations and regional aggregations.
Recently I came across a claim that the temperature anomalies are remarkably concentrated geographically. The hypothesis suggested, tentatively, by the author (Clive Best, blog on topic here) suggested that this might reflect contamination of the raw data by rapid urbanisation. NB his argument is very different from the idea that US data is corrupted by the urban heat island effect which is addressed here: https://skeptics.stackexchange.com/questions/10341/has-the-urban-heat-island-effect-on-the-us-temperature-record-been-underestimate)
He reports (my emphasis):
The anomalies from ~4000 stations all over the globe are then combined to give one global anomaly, yielding the familiar graph we know and love which shows ~0.6 deg.C rise since 1850. Looking in more detail however we discover that some parts of the world are not warming at all and some are even cooling.
His argument develops:
It immediately becomes obvious that the bulk of observed warming is concentrated in the Northern Hemisphere : Eastern Europe, Russia, central Asia, India, China, Japan, Middle East, North Africa. These are all areas of rapid population increase, development and industrialisation. There is essentially no warming at all in the Southern Hemisphere. Bolivia, Peru, Paraguay and Argentina all appear to be cooling. Even Australia and Zealand are static or cooling. The US is evenly divided and the UK shows essentially no signal at all.
...Could much of the observed temperature rise over the last 6 decades be simply due to increasing urbanisation and development since ~1960 ?
Climate models don't produce even warming across the world so there could be explanations perfectly consistent with the observations of major regional differences. So my question is: does the large variation in regional temperature anomalies have a straightforward explanation in mainstream warming theory or is it a sign that some regional records are contaminated by urban development?
NB Best used the data from HADCRUT3 released by the UK Met Office, but it is also obvious in the NOAA GSOD dataset which is conveniently available to 2010 in Google's BigQuery as a sample dataset (you can also download it if you have the capacity process it).