For the last one decade, NASA has been reporting that the year that ended was the warmest in a century and continues to say again that the year 2014 ranks as Earth’s warmest since 1880, collaborating two reports by NASA and National Oceanic and Atmospheric Administration (NOAA) scientists.
The 10 warmest years, with the exception of 1998, have now occurred since 2000 and the trend continues to show a long-term warming of the planet, said NASA’s Goddard Institute of Space Studies (GISS) in New York.
In an independent analysis of their own data, NOAA scientists also found 2014 to be the warmest on record.
Since 1880, Earth’s average surface temperature has warmed by about 1.4 degrees Fahrenheit (0.8 degrees Celsius), a trend that 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.
“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 GISS Director Gavin Schmidt.
While 2014 temperatures continue the planet’s long-term warming trend, scientists still expect to see year-to-year fluctuations in global temperature caused by El Niño or La Niña, which play crucial role to warm or cool the tropical Pacific. However, 2014 is an exception as it was an El Niño-neutral year.
“NOAA provides decision makers with timely and trusted science-based information about our changing world,” said Richard Spinrad, NOAA chief scientist. “As we monitor changes in our climate, demand for the environmental intelligence NOAA provides is only growing.”
Regional differences in temperature are due to weather dynamics than the global mean, they said. In fact, parts of the Midwest and East Coast were unusually cool, while Alaska and three western states – California, Arizona and Nevada – underwent the warmest year in 2014 on record, said NOAA.
The GISS analysis incorporates surface temperatures from 6,300 weather stations, ship- and buoy-based observations of sea surface temperatures, and from Antarctic research stations. The result is an estimate of the global average temperature difference from a baseline period of 1951 to 1980.
NOAA scientists used similar raw temperature data, but a different baseline period. They also employ their own methods to estimate global temperatures.
NASA monitors Earth’s vital signs from land, air and space with a fleet of satellites, as well as airborne and ground-based observation campaigns.