2017 was world’s second-hottest year on record, federal scientists say

Federal government researchers said Thursday that 2017 was the second-hottest year on record in terms of global average surface temperatures.

The finding by NASA follows three years in a row in which global temperature hit a new record. Last year’s average temperature was eclipsed only by 2016’s.

The heat average is part of a trend of more than four decades of rising global temperatures, which researchers say is nearly certain to be a sign of climate change, attributable primarily to greenhouse gas emissions caused by human activity.

“We are in a long-term warming trend, despite the ups and downs that we sometimes get on an annual basis,” Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, told reporters.{mosads}

NASA released its research jointly Thursday with the National Oceanic and Atmospheric Administration (NOAA). But NOAA uses slightly different methodology, so it concluded that 2017 was only the third-hottest year on record. Records go back to 1880 for both agencies.

NASA concluded that 2017’s average was 1.62 degrees Fahrenheit above the 1880 to 1951 average. NOAA said the temperature was 1.51 degrees above the 20th-century average.

President Trump and many in his administration are skeptical of the role human activity plays in climate change, and have expressed doubt about the scientific consensus that human-caused greenhouse gas emissions are the main cause of global warming.

The administration has worked to undo nearly every climate change policy from the Obama administration.

Nevertheless, Schmidt and NOAA’s Deke Arndt said the process of compiling the report was no different than it was in previous administrations: without political interference.

“The analysis we conducted this year was conducted in the exact same way, the exact same amount of rigor, as it has been every year,” Arndt, chief of NOAA’s National Climatic Data Center, told reporters, noting he’s been there nine years.

Schmidt agreed, saying, “We’ve had no input from political appointees.”

Both agencies found that if it weren’t for the El Niño climate pattern in 2017, it would have been the hottest year. And both say that the five warmest years on record have all happened since 2010.

The analyses both closely match findings by the World Meteorological Organization and the United Kingdom’s Meteorological Office, two of the preeminent authorities on temperature records.

—Updated at 12:13 p.m.