In a powerful testament to the warming of the planet, two leading U.S. science agencies Wednesday jointly declared 2016 the hottest year on record, surpassing the previous record set just last year — which itself had topped a record set in 2014.
Average surface temperatures in 2016, according to the National Oceanic and Atmospheric Administration, were 0.07 degrees Fahrenheit warmer than 2015 and featured eight successive months (January through August) that were individually the warmest since the agency’s records began in 1880.
The average temperature across the world’s land and ocean surfaces was 58.69 Fahrenheit, or 1.69 degrees above the 20th-century average of 57 degrees, NOAA declared. The agency also noted that the record for the global temperature has now successively been broken five times since the year 2000. The years 2005 and 2010 were also record warm years, according to the agency’s data set.
NASA concurred with NOAA, also declaring 2016 the warmest year on record in its own data set that tracks the temperatures at the surface of the planet’s land and oceans, and expressing “greater than 95 percent certainty” in that conclusion. (In contrast, NOAA gave a 62 percent confidence in the broken record.)
NASA found a bigger leap upward of temperatures in 2016, measuring the year as .22 degrees Fahrenheit higher than the prior record year of 2015. The agency also noted that since the year 2001, the planet has seen “16 of the 17 warmest years on record.”
Last year “is remarkably the third record year in a row in this series,” said Gavin Schmidt, who directs NASA’s Goddard Institute of Space Studies, in a statement. “We don’t expect record years every year, but the ongoing long-term warming trend is clear.”
The record comes two days before Donald Trump, who has tweeted that global warming is a “hoax,” assumes the presidency and, with it, control over the two science agencies that announced these records. It is also the same day that Scott Pruitt, Trump’s controversial nominee for the Environmental Protection Agency, is appearing before the Senate in an often-tense confirmation hearing in which he has been questioned about climate change. Pruitt has previously written that the “debate” over climate change is “far from settled.”
Trump’s other nominees, such as State Department nominee Rex Tillerson and Interior Department nominee Ryan Zinke, have been less dismissive of climate change in their confirmation hearings, acknowledging at least some human contribution to the phenomenon but also raising questions either about the extentto which it is human-caused or about our capacity to predict the consequences. On Wednesday, Pruitt acknowledged that climate change is not a “hoax” and said that “the climate is changing, and human activity contributes to that in some manner.”
Scientists have been far less guarded. “2016 is a wake-up call in many ways,” Jonathan Overpeck, a climate scientist at the University of Arizona, said of the year’s temperatures. “Climate change is real, it is caused by humans, and it is serious.”
NASA and NOAA produce slightly different records using somewhat different methodologies, but have now concurred on identifying 2014, 2015 and 2016 as, successively, the three warmest years in their records. There was a noticeable difference this year, however, in how much two agencies judged 2016 to have surpassed 2015. NASA was more bullish — a difference that Schmidt, in a press call Wednesday, attributed to different ways of measuring the Arctic.
“The warming in the Arctic has really been exceptional, and what you decide to do when you’re interpolating across the Arctic makes a difference,” Schmidt said.