April through September 2014 were the hottest months on record. In this animation, the deviation of global temperatures away from the average temperature are revealed, with blue being below average and red above average. (NASA Goddard Institute for Space Studies)

The year 2014 ranks as Earth’s warmest year since 1880, according to two separate reports by NASA and National Oceanic and Atmospheric Administration (NOAA) scientists. Excluding 1998, the 10 warmest years have all occurred since 2000.

Since temperature records began in 1880, the global average has increased by 1.4° Fahrenheit. This trend is largely driven by the increase in carbon dioxide and other human emissions into the planet’s atmosphere. The majority of that warming has occurred in the past three decades.

Josef Friedhuber |Getty Images — Climate change is melting polar ice caps and raising sea levels. Josef Friedhuber | Getty Images

“That might not seem like very much, but in terms of the climate, it’s actually quite a big deal,” said Dr. Gavin Schmidt, Director at NASA’s Goddard Institute for Space Studies (GISS), of the temperature increase.

“This is the latest in a series of warm years, in a series of warm decades. While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases,” said Schmidt.

Although the report shows evidence of the long-term warming trend, scientists still expect to see year-to-year fluctuations in average global temperature caused by the phenomona El Niño or La Niña, which warm or cool the tropical Pacific. Surprisingly, 2014’s record warmth occurred during an El Niño-neutral year.

The video above shows a time series of five-year global temperature averages, mapped from 1880 to 2014, as estimated by scientists at NASA’s Goddard Institute for Space Studies in New York.

NASA says that regional differences in temperature are more affected by weather dynamics than the global mean. In NASA’s news release, they point out: “in the U.S. in 2014, parts of the Midwest and East Coast were unusually cool, while Alaska and three western states – California, Arizona and Nevada – experienced their warmest year on record.”