2015 warmest year on record

NASA and NOAA have announced that 2015 was the warmest year on record, clearly ahead of the previous record year, 2014.

NASA illustration showing 2015 was the warmest year since modern record-keeping began in 1880.

It can be seen from the graphic that the most warming is in the northern hemisphere, especially in the Arctic.

Radio NZ: Last year was hottest on record globally – NASA

Data from NASA and the National Oceanic and Atmospheric Administration showed that in 2015, the average temperature across global land and ocean surfaces was 0.90°C above the 20th century average, surpassing 2014’s previous record by 0.16 degrees.

During the final month, the December combined global land and ocean average surface temperature was the highest on record for any month in the 136-year record.

This was the fourth time a global temperature record had been set this century, the agencies said in a summary of their annual report.

“2015 was remarkable even in the context of the larger, long-term warming trend,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies.

The sharp increase in 2015 was driven in part by El Nino, a natural weather cycle in the Pacific that warms the ocean surface every two to seven years. But scientists say human activities – notably burning fossil fuels – were the main driver behind the rise.

“We would not have seen the record warming without the long-term trend,” said Mr Schmidt.

  • 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 last year by 0.29°F (0.16°C) and marking the fourth time a global temperature record has been set this century. This 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.

All the warmest years since1880 have been since 1998.

A summary of the NOAA climate data here.

Sixteen Warmest Years (1880–2015)

The following table lists the global combined land and ocean annually-averaged temperature rank and anomaly for each of the 16 (two tied at #15) warmest years on record.

1 2015 0.90 1.62
2 2014 0.74 1.33
3 2010 0.70 1.26
4 2013 0.66 1.19
5 2005 0.65 1.17
6 (tie) 1998 0.63 1.13
6 (tie) 2009 0.63 1.13
8 2012 0.62 1.12
9 (tie) 2003 0.61 1.10
9 (tie) 2006 0.61 1.10
9 (tie) 2007 0.61 1.10
12 2002 0.60 1.08
13 (tie) 2004 0.57 1.03
13 (tie) 2011 0.57 1.03
15 (tie) 2001 0.54 0.97
15 (tie) 2008 0.54 0.97

Much of the record warmth for the globe can be attributed to record warmth in the global oceans.

Global Analysis – Annual 2015