2015 was the warmest year ever recorded on Earth

2015 was the warmest year ever recorded on Earth

The globally averaged temperatures from January through December 2015 were 0.87 degrees Celsius above the norm (defined as a 1951–1980 base period). The previous record—set last year—was 0.74°C above the norm. 2015 was more than 1°C warmer than temperatures in 1880, when consistent record-keeping began.
Regionally, 2015 was the second warmest year on record for the United States, Africa, and Europe. It was the warmest year for Asia and South America. Globally, new monthly temperature records were set in every month except January and April.
The map is drawn from data acquired from roughly 6,300 meteorological stations around the world; by ship- and buoy-based instruments measuring sea surface temperature; and by Antarctic research stations. The global observation is coordinated by the World Meteorological Organisation.
The 2015 temperature record continues a long-term warming trend that has largely been driven by increased carbon dioxide and other greenhouse gases that humans have emitted into the atmosphere. Most of the warming has occurred in the past 35 years, with 15 of the 16 warmest years on record occurring since 2001.

Phenomena such as El Niño or La Niña, which warm or cool the tropical Pacific Ocean, can contribute to short-term variations in global average temperature. The graph shows temperature trends in relation to El Niño and La Niña events.
In the past, the highest global temperature records were often set in El Niño years, which suggests that 2016—with El Niño going strong as of mid-January—appears likely to be another very warm year.

Climate change is the challenge of the generation. Now is the time to act on climate. (NASA, January 2016)