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Written by Alex Cuclis, Research Scientist, Air Quality and Emissions
Temperatures Anomalies - Unexpected Deviations
One measure of climate change is the temperature anomaly or the deviation in temperature relative to the average value at the same location. Temperature anomalies allow scientists to see global trends that are hidden when absolute temperatures from different places and altitudes are averaged together. The temperature anomalies are taken all over the earth – land and sea, and scientists have observed that the temperatures have been rising for over 100 years. The anomalies shown in the table below are the deviations in °F from the average temperatures in the 20th century.
The data in the table is ordered from warmest to coolest year from 1998 – 2015. Data with yellow numbers are the hottest in each respective column. El Nino was strong in 1998, making it significantly warmer than other years during the 1990’s. Learn more about Temperature Anomalies from NOAA
According to the IPCC, from 1951-2012 average global temperatures rose by 0.22°F per decade, however, temperatures from 1998-2012 only rose 0.09°F per decade. This period still shows warming, but is often referred to as a “hiatus” from the rate of warming observed in the previous century and is less than what was anticipated by the models.
2014 was the hottest year on record. 2015 is on track to be the hottest year ever. If trends continue, 2015 will be 0.16-0.20°F warmer than 2014. That temperature rise would be more than twice any increase ever seen between any hottest and second hottest year on record. The large increase is partially attributed to what some say will be the strongest El Nino seen in decades.