The year 2019 was the second-warmest ever recorded on Earth, trailing only the year 2016, according to two independent analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA). The past five years have been the warmest of the last 140 years, when modern record-keeping began, said a NASA press release.
Temperatures last year were 1.8 degrees Fahrenheit warmer than the mean temperature from 1951 to 1980, scientists from NASA's Goddard Institute for Space Studies (GISS) found. Since the 1880s, the average global surface temperature has been rising, with the average temperature now more than 2 degrees Fahrenheit above that of the late 19th century.
"The decade that just ended is clearly the warmest decade on record," GISS Director Gavin Schmidt said in a NASA press release. "Every decade since the 1960s clearly has been warmer than the one before."
The scientists used climate models and statistical analysis of global temperature data, the release said.
"We crossed over into more than 2 degrees Fahrenheit warming territory in 2015 and we are unlikely to go back," Schmidt said in the release. "This shows that what's happening is persistent, not a fluke due to some weather phenomenon: we know that the long-term trends are being driven by the increasing levels of greenhouse gases in the atmosphere."
Some scientists have warned that at between 1.8 degrees and 3.6 degrees Fahrenheit above preindustrial levels, we could encounter or points of no return, and that we may have already crossed some of these points.
The 2015 Paris Agreement aims to limit warming this century to "well below" 3.6 degrees Fahrenheit and to push even further toward a goal of a rise of no more than 2.7 degrees Fahrenheit. The US under President Donald Trump is withdrawing from the Paris Agreement.
Originally published Jan. 15, 10:17 a.m. PT.
Update, 1:11 p.m.: Adds information about climate "tipping points" and the Paris Agreement.