evidence: Let’s look more closely at why these adjustments are made. [...] GISTEMP also adjusts to account for the effects of urban heat islands, which are differences in temperatures between urban and rural areas. [...] Independent analyses conclude the impact of station temperature data adjustments is not very large. Upward adjustments of global temperature readings before 1950 have, in total, slightly reduced century-scale global temperature trends. Since 1950, however, adjustments to input data have slightly increased the rate of global warming recorded by the temperature record by less than 0.1 degree Celsius (less than 0.2 degrees Fahrenheit).