The Average Temperature Anomaly is a measure used by many in the Global Warming Funding Industry™ to assess the degree of deviation, above or below, from some baseline temperature by some claimed cause of global warming. The most commonly claimed cause these days is the amount of atmospheric CO2. The most commonly used baseline temperature is the period from around 1856, the nominal start of the Industrial Age and its associated increase in man-caused atmospheric CO2.
This graph, via NOAA, is that Average Temperature Anomaly since 1896, when the Industrial Age was well underway. ClimDiv is an NOAA-developed climate database, and USCRN is a network of NOAA climate stations.
Doesn’t seem like there’s much there in the way of global warming….