According to NASA’s analysis, in 2015 the Earth was 0.87 degrees C (1.57 degrees Fahrenheit) warmer than the average for 1950 to 1981 – compared to 0.74 degrees C in 2014. NASA said that the temperature changes are largely driven by increased carbon dioxide and other human-made emissions into the atmosphere.
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Because of the wide margin over 2014, NASA calculated that 2015 was a record with 94 percent certainty, more than double the certainty it had a year ago when announcing 2014 as a record. Fifteen of the 16 warmest years on record occurred since 2001.
Scientists cite greenhouse gas emissions from burning fossil fuels and deforestation as the primary cause of the heat. Last year was also the 39th year in a row with above average global temperatures.
The Northern Hemisphere saw the biggest rise in land temperatures, finishing 2.59° F hotter than the 20th century average. We basically knew this – scientists have been calling it since at least July – but now that the official numbers are in, we can see just how wacky a year it was.
“Yet, despite breaking the old global temperatures “by far, ‘ the observations only approached the climate model projections for the temperature of an ‘average” year for 2015″, he said.
Both NASA and NOAA separately analyzed the global temperature data and came to this same conclusion.
As we’ve been reporting throughout the year, ten out of twelve months in 2015 – every month except January and April – broke its respective monthly temperature record.
With most of the warming since 1880 occurring in the last 35 years, we literally live in a different, warmer world than previous generations.
Odds are 2016 will be even hotter than previous year, said Tom Karl, director of NOAA’s National Centers for Environmental Information. NASA Goddard Institute for Space Studies (GISS) Director Gavin Schmidt expressed that El Niño had a significant effect over 2015’s warm temperature, yet the increasing trend and the record-breaking heat were products of a long-term cumulative effect.
The World Meteorological Organization also reports that 2011-15 has been the warmest five-year period on record.
This illustration shows 2015 average temperatures related to the average from 1951 to 1980.
Karl, however, said 2015 would have likely been a record even without El Nino.
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Once the El Niño cycle began to affect temperatures after mid-year, “October, November, and December were record warm anomalies for any month in the record”, he added.
