The conventional use of ‘globally averaged temperatures’ causes ambiguity in our perception of human climate effects. Satellite images show distinct clusters or 'nodes' of population, light, CO2, heat, and likely water vapour. These urban nodes juxtaposed with the intervening rural dark areas form a 'mosaic' perspective of the anthropogenic effects on climate. Over-averaging of these nodes to indicate a 'blanketing' effect and hiding the mosaic is likened to mis-diagnosing sharp appendicitis pain.