Who: The year 2015
What: Earth’s warmest year since 1880
When: Declared by NASA & NOAA on 20 January 2016
The globally averaged temperature over land and ocean surfaces for 2015 was the highest among all years since modern record keeping began in 1880.
It was revealed by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) on 20 January 2016 after an independent analysis.
Key facts related to global climate patterns in 2015
• During 2015, the average temperature across global land and ocean surfaces was 1.62°F (0.90°C) above the 20th century average.
• This was the highest among all 136 years in the 1880–2015 record, surpassing the previous record set in 2014 by 0.29°F (0.16°C) and marking the fourth time a global temperature record has been set this century.
• 2015 is also the largest margin by which the annual global temperature record has been broken.
• Ten months had record high temperatures for their respective months during the year. The five highest monthly departures from average for any month on record all occurred during 2015.
• Record warmth was broadly spread around the world, including Central America, South America, Europe western Asia, Siberia, regions of eastern and southern Africa, equatorial Pacific, a large swath of the western North Atlantic, most of the Indian Ocean and parts of the Arctic Ocean.
• During 2015, the globally-averaged sea surface temperature was 1.33°F (0.74°C) above the 20th century average. This was the highest among all years in the 1880–2015 record, surpassing the previous record of last year by 0.20°F (0.11°C).
• According to data from NOAA analyzed by the Rutgers Global Snow Lab, the average annual Northern Hemisphere snow cover extent during 2015 was 9.5 million square miles.
• This was the 11th smallest annual snow cover extent since records began in 1968 and smallest since 2008. The first half of 2015 saw generally below-normal snow cover extent, with above-average coverage later in the year.
• Recent polar sea ice extent trends continued in 2015. The average annual sea ice extent in the Arctic was 4.25 million square miles, the sixth smallest annual value of the 37-year period of record.
• The annual Antarctic sea ice extent was the third largest on record, at 4.92 million square miles, behind 2013 and 2014.
Global climate patterns in December 2015
• The average temperature across global land and ocean surfaces was 2.00°F (1.11°C) above the 20th century average.
• This was the highest for December in the 1880–2015 record, surpassing the previous record of 2014 by 0.52°F (0.29°C).
• The December temperature departure from average was also the highest departure among all months in the historical record and the first time a monthly departure has reached +2°F from the 20th century average.
• The average Arctic sea ice extent for December was 300,000 square miles (6.0 percent) below the 1981–2010 average.
• This was the fourth smallest December extent since records began in 1979, according to analysis by the National Snow and Ice Data Center based on data from NOAA and NASA.
• Antarctic sea ice during December was 100,000 square miles (0.9 percent) below the 1981–2010 average.
• According to data from NOAA analyzed by the Rutgers Global Snow Lab, the Northern Hemisphere snow cover extent during December was 190,000 square miles below the 1981-2010 average.
• This was the 19th smallest December Northern Hemisphere snow cover extent in the 50-year period of record.
Climate change is the challenge of the 21st century and it affects every person on Earth. The planet’s average surface temperature has risen about 1.8 degrees Fahrenheit (1.0 degree Celsius) since the late-19th century, a change largely driven by increased carbon dioxide and other human-made emissions into the atmosphere.
Most of the warming occurred in the past 35 years, with 15 of the 16 warmest years on record occurring since 2001. 2014 was the first time the global average temperatures were 1 degree Celsius or more above the 1880-1899 average.
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. A warming El Niño was in effect for most of 2015.
This is the second year in a row of record temperatures and what is so interesting is that the warmest temperatures often occur the year after an El Nino, like in 1998 compared to 1997.
Considering the above facts, it is high time policy makers around the world should stand up, take notice and take appropriate actions to mitigate the situation.