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It’s official: 2017 was one of the hottest years on record

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Either the second- or the third-warmest

This map shows Earth’s average global temperature from 2013 to 2017, as compared to a baseline average from 1951 to 1980, according to an analysis by NASA’s Goddard Institute for Space Studies. Yellows, oranges, and reds show regions warmer than the baseline.
Image: NASA’s Scientific Visualization Studio

Last year was either the second- or the third-warmest year on record, depending on whether you ask NASA’s Goddard Institute for Space Studies or the National Oceanic and Atmospheric Association.

2017 was the second-hottest year, behind only 2016, according to NASA, which pegs the world’s average temperatures at 1.62 degrees Fahrenheit (0.90 degrees Celsius) warmer than the 1951 to 1980 mean. But according to NOAA, 2017 was the third warmest on record, behind 2016 and 2015. The two government agencies ranked 2017 differently because they use slightly different methods to calculate world temperatures.

Despite the difference, the long-term warming trends are very clear, Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, said during a press conference. “The overall picture is very, very similar and coherent,” Schmidt said. “We’re in a long-term warming trend.”

Today’s government reports are in clear contrast with what the president of the United States, Donald Trump, has repeatedly claimed. In December, as some parts of the US were experiencing frigid temperatures and record amounts of snow, Trump joked in a tweet that “we could use a little bit of that good old Global Warming,” and mocked other countries for working together to tackle climate change as part of the Paris climate deal. In June, Trump announced the US will withdraw from the agreement, making it the only country in the world to reject it.

But at the press conference today, Schmidt reiterated that all the warming we’ve been witnessing in the last 60 years is due to us, in particular the the increasing levels of heat-trapping greenhouse gases like carbon dioxide we’ve been pumping into the atmosphere.

The five hottest years on record have all occurred since 2010, according to both NASA and NOAA. The world has warmed up by 2 degrees Fahrenheit (a bit more than 1 degree Celsius) since 1880. And despite the year-to-year variability due to climate patterns like El Niño, which tends to increase global temperatures, “the long-term trends are very clear,” said Deke Arndt, chief of the monitoring section at NOAA’s National Centers for Environmental Information. In fact, 2017 ranked among the hottest years on record, even without an El Niño, which spiked temperatures in 2016.

NOAA’s data indicated that the US specifically had an average temperature of 54.6 degrees Fahrenheit in 2017, ranking it behind 2012 (55.3 degrees Fahrenheit) and 2016 (54.9 degrees Fahrenheit). Last year was also extreme in terms of natural disasters for the US: the country experienced 16 total, including wildfires, droughts, and major hurricanes — which killed at least 362 people. Overall, these weather and climate disasters cost the US a record $306 billion.

Beyond the US, 2017 was the second-warmest year for South America. On January 27th, 2017, thermometers in the Argentinian city of Puerto Madryn hit 110 degrees Fahrenheit (over 43 degrees Celsius), a record high temperature that far south, according to NOAA. The Arctic is also warming up about twice as fast as the rest of the world. As sea ice melts, less sunlight is reflected back into space, retaining even more heat. Sea ice in the Arctic is continuing to disappear: in December 2017, for instance, the extent of Arctic sea ice was the second smallest since records began in 1979. Some areas, mostly in the Southern Ocean around Antarctica, saw cooler temperatures on average. But despite regional differences, the world is warming up consistently. “The planet is moving remarkably uniformly,” Schmidt said.

Image: NOAA

Despite the Trump administration’s stances on climate change, Schmidt and Arndt said that both the NASA and NOAA analyses were conducted “in the exact same way and with the exact same amount of rigor” as previous years. No input was received by the administration.

“NASA and NOAA work on providing the best science that we can and the best analysis that we can,” Schmidt said. “We don’t really get involved in the policy aspects of this.”