Even without El Niño, 2017 temperatures still soared

Last year was one of the worst scorchers in modern history, and the hottest to take place without a boost from El Niño, scientists from U.S. and international agencies announced today. NASA says 2017 was the second warmest on record, with global temperatures at 0.90°C above a 1951–1980 average; the National Oceanic and Atmospheric Administration (NOAA) ranked it third, with temperatures at 0.84°C above the average for the entire 20th century. Overall, 17 of the 18 warmest years since 1880 have occurred since 2001, with the past three markedly warmer than the record-setters of the previous decade. That trend is in line with continued human-driven climate change; however, 2015 and 2016 got a boost from El Niño, the short-term Pacific Ocean weather pattern. The discrepancies in the NASA and NOAA rankings come down to both different baselines and differences in how researchers interpret temperature readings from limited weather stations across the Arctic, which has seen rapid warming in recent decades. The 2017 temperature estimates show the greatest spread in 3 decades, according to Berkeley Earth, a group of independent researchers that produced its own estimate. Notably, in their first year under President Donald Trump, NASA and NOAA released their estimates uncensored, despite the White House’s critical view of regulations and international deals meant to curb global warming.