The year 2014 was the warmest since the beginning of weather record keeping in 1880, U.S. officials said Friday. Earth's average surface temperature has warmed by about 0.8 degrees Celsius since 1880, according to the US space agency NASA. In an independent analysis of the raw data, also released Friday, scientists with the National Oceanic and Atmospheric Administration (NOAA) also found 2014 to be the warmest on record. "This is the latest in a series of warm years in a series of warm decades," dpa quoted director of NASA's Goddard Institute of Space Studies (GISS) in New York Gavin Schmidt as saying. Long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases. The 10 warmest years in the instrumental record with the exception of 1998 have occurred since 2000, NASA said in a press release. The trend continues a long-term warming of the planet, according to an analysis of surface temperature measurements by scientists at GISS.