Another year, another broken temperature record. As early data predicted, NASA and the National Oceanic and Atmospheric Administration (NOAA) have now reported that globally, 2016 was the warmest year since records began in 1880. That puts us on a streak of three years in a row that have surpassed previous records, painting a worrying picture of a long-term warming trend.
Taking a global average of surface temperatures, 2016 was found to be 1.78º F (0.99º C) warmer than the mean figures from the middle of the 20th century. Overall, the planet has warmed by about 2º F (1.1º C) since 1880, and the 16 years we've had of the 21st century so far are all in the top 17 hottest years on record.
Along with the dubious honor of hottest year so far, 2016 took a hammer to plenty of individual records too, with eight of its 12 months breaking the previous records for hottest average temperature for each respective month. A weak La Niña weather pattern may have slightly cooled things down later in the year, but the months of October to December were still among the warmest known.
"2016 is remarkably the third record year in a row in this series," says Gavin Schmidt, Director of NASA's Goddard Institute for Space Studies (GISS). "We don't expect record years every year, but the ongoing long-term warming trend is clear."
These records were set as a global average, which means that not every part of Earth would have experienced above-average temperatures for 2016. In the continental US, the annual mean temperature was the second warmest, while the Arctic was pummeled by a heatwave, resulting in record-low sea ice in the area. Variations like this may be responsible for skepticism of the kind that leads to Senators bringing snowballs onto the Senate floor.
This conclusion was reached by both NASA and NOAA independently, based on data gathered from 6,300 weather stations around the world, research stations in Antarctica and sea surface temperature observations from ships and buoys. From there, the two organizations use slightly different means of calculating their estimates, with NASA saying it's over 95 percent certain in claiming 2016 to be the warmest year on record.