Jan. 15 (UPI) -- Last year was the second warmest in recorded history, according to scientists as NASA and the National Oceanic and Atmospheric Administration.
Every year, researchers at NASA and NOAA independently compile and process land and sea surface temperature data to produce an average global surface temperature.
The statistical analysis and climate models deployed by each agency came to the same conclusion: 2019 was the second hottest in recorded history. Only 2016 was hotter.
Scientists at NASA's Goddard Institute for Space Studies, GISS, determined 2019 was 1.8 degrees Fahrenheit, or 0.98 degrees Celsius, warmer than the mean temperature from 1951 to 1980. Climate scientists at NOAA calculated that 2019 was 1.71 degrees Fahrenheit, 0.95 degrees Celsius, warmer than the 20th-century average.
"The decade that just ended is clearly the warmest decade on record," Gavin Schmidt, director of GISS, said in a news release. "Every decade since the 1960s clearly has been warmer than the one before."
Like most climate scientists, Schmidt blamed the record temperatures on greenhouse gas emissions.
"We crossed over into more than 2 degrees Fahrenheit warming territory in 2015 and we are unlikely to go back," Schmidt said. "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."
NASA's modeling efforts involved the compilation of temperature data collected from thousands of weather stations, as well as data recorded by ocean buoys, research vessels and Antarctic research stations.
Because recording practices are adapted, weather stations change and buoys move, no data set is quite the same, but scientists work to standardize the temperature data for accurate year-to-year comparisons.
"NOAA scientists used much of the same raw temperature data, but with a different interpolation into the Earth's polar and other data-poor regions," according to NASA.
Earlier this week, scientists reported that Earth's oceans have never been hotter.