2015 Was Hottest Year in Historical Record, Scientists Say

Scientists started predicting a global temperature record months ago, in part because an El Niño weather pattern, one of the largest in a century, is releasing an immense amount of heat from the Pacific Ocean into the atmosphere. But the bulk of the record-setting heat, they say, is a consequence of the long-term planetary warming caused by human emissions of greenhouse gases.

“The whole system is warming up, relentlessly,” said Gerald A. Meehl, a scientist at the National Center for Atmospheric Research in Boulder, Colo...

The American agencies [NOAA and NASA] released figures on Wednesday showing that 2015 was the warmest year in a global record that began, in their data, in 1880. British scientists released figures showing 2015 as the warmest in a record dating to 1850. The Japan Meteorological Agency had already released preliminary results showing 2015 as the warmest year in a record beginning in 1891.