A new report names 2014 as the warmest year since records were first kept in 1880. Across all land and ocean surfaces, the average temperature was up 1.24 degrees Fahrenheit over the 20th century average, according to numbers released Friday by the National Oceanic and Atmospheric Administration (NOAA).
"Climate change is the major challenge of our generation," Michael Freilich, director of NASA’s Earth Science Division, told reporters. "When averaged over the globe, 2014 was the warmest year on record."
The same conclusion was reached by NASA, which also called 2014 the warmest year on record in a separate analysis released on Friday. Last week, the Japan Meteorological Agency released a report that named 2014 as the warmest of the last 120 years.
Greenhouse gases couldn't definitely be blamed for 2014's record temperatures, said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, but they are responsible for the long-term warming trends.
If the entire world stopped emitting greenhouse gases tomorrow, he said, it still would take a while to stall the rising temperatures.
"It wouldn’t affect things very fast," Schmidt said. "You would start to see changes in the carbon cycle in a decade or so and then temperature changes after that."
Not everybody experienced warmer weather. In the Midwest, the "polar vortex" caused a colder-than-average year. But in parts of western Alaska, eastern Russia, the interior of South America, and parts of both Australian coasts, people experienced record high temperatures.
The biggest increase was over the oceans, where temperatures were 1.03 degrees Fahrenheit above the 20th century average, which is also a new record.
"Every continent had some aspect of record high temperatures," Thomas R. Karl, director of NOAA's National Climatic Data Center, said.
Both NASA and NOAA had 2014 passing the previous record-holders: 2005 and 2010. The warmest December since 1880 helped push 2014 into record territory.
Overall, nine out of the 10 warmest years on modern record have occurred in the 21st century. The lone exception was 1998, which happened to be an especially strong El Nino year.
With greenhouse gas emissions still soaring, the warming trend isn't expected to stop anytime soon. That means things could get really hot in the future, according to Schmidt.
"The previous warmest years were all El Nino years, while this year wasn’t," he said. "It wouldn’t be a surprise if the next year that starts with an El Nino will be the hottest year on record."