Does the regional localisation of global temperature trends suggest contamination by urban development?
The blog article suggests that the increase in "waste heat" from growing urbanisation is biasing the temperature observations.  The problem with this argument is that the heat generated directly from burning fossil fuels is far too small to make a difference, compared to the change in the Earths energy balance due to increasing greenhouse gasses.  See: 


  Integrating anthropogenic heat flux with global climate models Authors
  
  Mark G. Flanner
  
  Atmospheric Science, Volume 36, Issue 2, January 2009. 
  DOI:10.1029/2008GL036465
  
  Abstract 1 Nearly all energy used for human purposes is dissipated
  as heat within Earth's land–atmosphere system. Thermal energy released
  from non-renewable sources is therefore a climate forcing term.
  Averaged globally, this forcing is only +0.028 W m−2, but over the
  continental United States and western Europe, it is +0.39 and +0.68 W
  m−2, respectively. Here, present and future global inventories of
  anthropogenic heat flux (AHF) are developed, and parameterizations
  derived for seasonal and diurnal flux cycles. Equilibrium climate
  experiments show statistically-significant continental-scale surface
  warming (0.4–0.9°C) produced by one 2100 AHF scenario, but not by
  current or 2040 estimates. However, significant increases in
  annual-mean temperature and planetary boundary layer (PBL) height
  occur over gridcells where present-day AHF exceeds 3.0 W m−2. PBL
  expansion leads to a slight, but significant increase in atmospheric
  residence time of aerosols emitted from large-AHF regions. Hence, AHF
  may influence regional climate projections and contemporary
  chemistry-climate studies.


The blog article says:


  My guess is that 80% of this energy ends up as heat (2nd law
  thermodynamics). Assuming that  energy consumption is concentrated
  mostly in urban areas then the net “anthropogenic”  heating in those
  areas works out at around 5 watts/m2. This  then leads to  an average
  1.4 degreeC. rise in temperature for urban areas.  Anyone who has lived in the city knows from experience that the surrounding
  countryside is indeed  some 1-2 degrees colder.


Indeed the climatologists know that as well, they are not stupid, and hence "homogenise" the observations to remove these sorts of biases.  Note that if the bias were due to increasing urbanisation, this would be easily detectable by comparison with the observations from rural stations in the same region.  This is not rocket science (see my answer here for links on homogenization)!

Note also that increasing urbanisation would not necessarily cause an increase in local forcing, because as you increase the fossil fuel use, you also increase the area over which it is dissapated, which the author of the blog post also appears to have missed.