Earth’s global surface temperatures in 2017 ranked as the second-warmest since 1880, according to an analysis by NASA. In a separate, independent analysis, scientists at the National Oceanic and Atmospheric Administration (NOAA) concluded that 2017 was the third-warmest year in their record.
The difference in rankings is due to the different methods used by the two agencies to analyze global temperatures, although over the long-term the agencies’ records remain in strong agreement.
Both analyses show that the five warmest years on record all have taken place since 2010.
According to NASA:
Continuing the planet’s long-term warming trend, globally averaged temperatures in 2017 were 1.62 degrees Fahrenheit (0.90 degrees Celsius) warmer than the 1951 to 1980 mean … That is second only to global temperatures in 2016 …
The planet’s average surface temperature has risen about 2 degrees Fahrenheit (a little more than 1 degree Celsius) during the last century or so, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere. Last year was the third consecutive year in which global temperatures were more than 1.8 degrees Fahrenheit (1 degree Celsius) above late nineteenth-century levels.
Bottom line: Both NASA and NOAA report Earth’s long-term warming trend is continuing.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.