(CN) - The planet continued to warm at a blistering pace in 2015, shattering the mark for hottest year on record dating back to 1880, NASA scientists said Wednesday.
The United States experienced its second-warmest year, while global average temperatures in 2015 hurdled over 2014's record by 0.23 degrees Fahrenheit.
In an annual global temperature analysis, scientists from NASA and the National Oceanic Atmospheric Administration said the global warming trend is stronger than ever and that the odds of a sizzling 2016 are "better than even."
"If you're going to be betting, you'd bet that  is going to be warmer than 2015," NOAA environmental director Thomas Karl said.
Ten of 2015's monthly global temperatures tied or eclipsed previous records. In December, temperatures spiked more than one degree Fahrenheit above 20th century averages.
In the United States, December was both the warmest and wettest month on record and spawned disastrous unseasonal winter flooding on the Mississippi River and above-average rain to the drought-stricken West Coast. Overall, annual average temperatures in the nation were above 20th century averages for the 19th consecutive year.
Despite the prevalence of a strong El Nino, 2015's record heat was the result of a decades-long warming trend and not the powerful weather pattern.
"It was warm throughout the year and even though it's kind of picking up that El Nino assist in the last three months, even without El Nino this would have been the warmest year on record," Gavin A. Schmidt, head of NASA's climate-science unit, said. "We're really looking at a long-term trend; this is just a symptom of that long-term trend."
The two government agencies compiled separate analyses of global temperatures through ocean buoys and weather stations across the globe. British and Japanese scientists are releasing similar studies this year.
Karl said this past year was remarkable not solely because of the scorching global temperatures, but the distance it put between the 2014 record.
"In previous times when we've set records, the gap between the previous record and the new record has been substantially smaller than what we've seen this year," Karl said.
The scientists said in a press conference Wednesday that the back-to-back heat records are the product of several factors, including manmade sources of greenhouse gases. If 2016 breaks the newly set temperature record, it will be the first time scientists have seen three consecutive years of record heat.
Schmidt said long-term global warming is already causing heat waves, rising sea levels and the loss of mountain glaciers across the world.
According to the analyses, Asia and South America experienced their warmest years since records began in 1910, while Africa and Europe saw their second warmest year. Just one patch in the north Atlantic below Greenland saw record cold temperatures.
While the agencies keep independent temperature records, the experts agreed that there were few discrepancies in 2015.
"By and far, the big story here is record warmth that was spread throughout the world," Karl said. "All the oceans participated."
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