We just finished the second hottest year on Earth since global temperature estimates first became feasible in 1880. Although 2016 still holds the record for the warmest year, 2017 came in a close second, with average temperatures 1.6 degrees Fahrenheit higher than the mean.
2017’s temperature record is especially noteworthy, because we didn’t have an El Niño this year. Often, the two go hand-in-hand.
El Niño is a climate phenomenon that causes warming of the tropical Pacific Ocean waters, which affect wind and weather patterns around the world, usually resulting in warmer temperatures globally. 2017 was the warmest year on record without an El Niño.
We collect the temperature data from 6,300 weather stations and ship- and buoy-based observations around the world, and then analyze it on a monthly and yearly basis. Researchers at the National Oceanic and Atmospheric Administration (NOAA) do a similar analysis; we’ve been working together on temperature analyses for more than 30 years. Their analysis of this year’s temperature data tracks closely with ours.
The 2017 temperature record is an average from around the globe, so different places on Earth experienced different amounts of warming. NOAA found that the United States, for instance, had its third hottest year on record, and many places still experienced cold winter weather.
Other parts of the world experienced abnormally high temperatures throughout the year. Earth’s Arctic regions are warming at roughly twice the rate of the rest of the planet, which brings consequences like melting polar ice and rising sea levels.
Increasing global temperatures are the result of human activity, specifically the release of greenhouse gases like carbon dioxide and methane. The gases trap heat inside the atmosphere, raising temperatures around the globe.
We combine data from our fleet of spacecraft with measurements taken on the ground and in the air to continue to understand how our climate is changing. We share this important data with partners and institutions across the U.S. and around the world to prepare and protect our home planet.
Earth’s long-term warming trend can be seen in this visualization of NASA’s global temperature record, which shows how the planet’s temperatures are changing over time, compared to a baseline average from 1951 to 1980.
Learn more about the 2017 Global Temperature Report HERE.
Discover the ways that we are constantly monitoring our home planet HERE.