Catastrophic global warming skeptics have long said that climate research agencies and the IPCC were overstating the amount of global temperature increase due to the Urban Heat Island (UHI) effect - skeptics were just proven correct in a new Turkish study
(click on image to enlarge, source)
Read here. This image portrays the impact that dense urban areas can have on local temperatures. This is the UHI effect, which can literally stretch for miles causing regional temperatures to be higher. The UHI effect has nothing to do with greenhouse gases (e.g. CO2 emissions).
One means to determine the impact of UHI, plus confirm the influence of greenhouse gases, is to analyze and compare the minimum daily temperatures for urban areas versus the rural areas. If greenhouse gases have little impact on temperatures, than the rural daily minimum temperatures should reveal a a zero to slight increasing trend.
Turkish scientists, Ozdemir et al., did this type of comparison for temperature readings across the Anatolian Peninsula.
"Focusing on cities having over half a million inhabitants representative of urban conditions and much smaller towns representative of rural conditions - all of which also possessed continuous high-quality temperature data from 1965 to 2006 - the authors studied the four-decade trends in daily minimum air temperature at each location...the eight researchers report that "statistical analysis of daily minimum temperatures for the period between 1965 and 2006 suggest that there is no statistically significant increase in rural areas." However, they say that all of the urban sites, as well as the differences between urban and rural pairs, show significant increases in temperature, indicative of a strong urban heat island (UHI) effect over the region. In fact, as they describe it, the average "urban station is over 4°C warmer than rural."" [Huseyin Ozdemir, Alper Unal, Tayfun Kindap, Ufuk Utku Turuncoglu, Zeynep Okay Durmusoglu, Maudood Khan, Mete Tayanc, Mehmet Karaca 2012: Theoretical and Applied Climatology]
'C3' Conclusions: This Turkish study confirms what previous UHI effect studies have found: rural areas are not experiencing an increase in temperatures due to greenhouse gases. Because the dataset used to calculate global temperatures is dominated by urban and airport locations, overstating global warming has been the result. The UHI effect has never been adequately removed so as to provide an accurate picture of CO2-induced global warming. Simply put, to accurately determine actual global warming from greenhouse gases, only rural climate stations, based on the state-of-the-art USCRN technology and standards, should be used for the land surface global temperature dataset.