More evidence of global temperature measurment error rates

I have commented over the years on the epistemic and philosophical weakeness of global warming hysteria.  There are predicate facts which obviate much of the nonsense.

It is well established that climate is always changing.

There is no steady state climate.

There are cycles of warming and cooling.

Local climate change is only loosely linked to macro-global changes.

The greatest climate change affecting the most people are largely driven by local land use - agiculture, forestry, built environments, riverine management (lakes, reservoirs, etc.)

Reliable global temperature measurement only has fifty years of data (via satellites).  

All other records (tree rings, thermometers, etc.) are less complete, less reliable, and have larger margins of error.

The complete global temperature record is patchy, incomplete, has low precision, and poor consistency across data sets.

All climate and climate change is most heavily influenced by solar, planetary, geological, and natural processes.  The percent influenced by man-made processes is small and uncertain.  But real.

Nobody knows with any confidence the percentage of climate change which is due to human processes.

Nobody is confident about the status of the natural processes (warming or cooling?)

I have posted a number of times about the urban heat island issue and its affect on temperature data records.  

An urban heat island (UHI) is an urban area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces. A study has shown that heat islands can be affected by proximity to different types of land cover, so that proximity to barren land causes urban land to become hotter and proximity to vegetation makes it cooler. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.

There are two issues in terms of temperature records.  To the extent to which thermometers are located in urban areas which are warmer owing to UHI, then the record falsely indicates a warmer climate.  A decade or so ago, someone looked at all extant and continuing temperature collection sites.  After removing those which were within city environs, there was little change in national temperatures over several decades.

The second issue with urban located thermometer is closely related.  Independent of UHI, in a built environment, there is a greater probability that thermometers will end up being incidentally close to a distorting heat source.  There was an example some years ago with a weather station on a university campus.  When originally constructed nearly a hundred years ago, the university was on the periphery of a small town.  The city exploded in population and ended engulfing the university making the weather station subject to UHI.  In addition, it was later discovered, when the issue was investigated, the weather station area ended up being located a half a block from a facility with major HVAC venting, creating an additional false read of temperature.

Another recent study reinforces the overall issue of temperature measurement error.  From New Study Suggests Global Warming Could be Mostly an Urban Problem.  

A new study published in the scientific peer-reviewed journal, Climate, by 37 researchers from 18 countries suggests that current estimates of global warming are contaminated by urban warming biases.

The study also suggests that the solar activity estimates considered in the most recent reports by the UN’s Intergovernmental Panel on Climate Change (IPCC) likely underestimated the role of the Sun in global warming since the 19th century.

It is well-known that cities are warmer than the surrounding countryside. While urban areas only account for less than 4% of the global land surface, many of the weather stations used for calculating global temperatures are located in urban areas. For this reason, some scientists have been concerned that the current global warming estimates may have been contaminated by urban heat island effects. In their latest report, the IPCC estimated that urban warming accounted for less than 10% of global warming. However, this new study suggests that urban warming might account for up to 40% of the warming since 1850.

The study also found that the IPCC’s chosen estimate of solar activity appeared to have prematurely ruled out a substantial role for the Sun in the observed warming.

When the authors analysed the temperature data only using the IPCC’s solar dataset, they could not explain any of the warming since the mid-20th century. That is, they replicated the IPCC’s iconic finding that global warming is mostly human-caused. However, when the authors repeated the analysis using a different estimate of solar activity – one that is often used by the scientific community – they found that most of the warming and cooling trends of the rural data could actually be explained in terms of changing solar activity.

It will take many more such nails to seal the coffin of global warming hysteria.  It is obvious that human activities do in fact affect local climates (land use) and to an unknown but certainly marginal degree, global climate.  But reality is not as has been insistently presented.  Human activities are not a direct dial on future temperatures.  They are at best a contributing factor, at the margin, and with significant lag and not uncommonly with some beneficial aspects as well.