Last year was the hottest in modern history, according a report by US government scientists on Friday that found global warming reached a new and concerning level in 2014.
The average for sea and land surface temperatures "was the highest among all years since record keeping began in 1880," said the report by the National Oceanic and Atmospheric Administration (NOAA).
"Record warmth was spread around the world," said the NOAA report.
"The globally averaged temperature over land and ocean surfaces for 2014 was the highest among all years since record keeping began in 1880."
For the year, the average temperature was 1.24 degrees Fahrenheit (0.69 Celsius) above the 20th century average, beating the previous record-holding years of 2005 and 2010 by 0.07 F (0.04 C).