NASA

"2014 wasn't just the hottest year on record but also the 38^th year in a row with temperatures higher than the 20^th century average. The world’s climate scientists, in one of the most carefully compiled and reviewed documents in scientific history, claim that this trend is man-made, and that we’re heading for a 4 or 5 degree increase this century unless we change course. It's time we stopped debating whether climate change is really happening, and focused people's energy, expertise, and ideas on finding the best ways to prevent it."

ENDS

NASA researchers have calculated that 2005 was the hottest year on record.

Last year produced the highest annual average surface temperature worldwide since instrument recordings began in the late 1800s, according to NASA's Goddard Institute for Space Studies. The previous hottest year was 1998.