by Ron Clutz, December 18, 2018 in ScienceMatters

Over the last 40 years global-mean surface air temperature – ‘global temperature’ for short – has gained an extraordinary role in the science, politics and public discourse of climate change. What was once a number crudely calculated through averaging together a few dozen reasonably well-spaced meteorological time series, has become reified as an objective entitythat simultaneously measures Earth System behaviour, reveals the future, regulates geopolitical negotiations and disciplines the human imagination. Apart perhaps from GDP rarely can so constructed an abstract entity have gained such power over the human world.

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