UPDATE, Jan. 20, 2015
Some people apparently are skeptical about whether 2014 was actually the warmest on record. They cite probabilities provided by government researchers to support their skepticism. But at least some skeptics seem confused about the meaning of this statistical uncertainty.
Andrew Freedman of Mashable tackles the subject in a straightforward way. But the best point in his piece comes in the final paragraph:
At the end of the day, the discussion about a single calendar year obscures the more important long-term trend of warming air temperatures, warming and acidifying oceans along with melting ice sheets, all of which are hallmarks of manmade global warming. Including 2014, 13 of the top 15 warmest years have all occurred since 2000.
Last year turns out to be the hottest year on record for the Earth’s surface, according to climate researchers who analyzed average temperatures across the globe.
The year 2014 adds yet another dramatic page to the record book, which now shows that the 10 warmest years since 1880 have occurred since the year 2000 — with the exception of the record year of 1998, which now stands as the fourth warmest on record.
The data were released this morning, with additional information provided in a telephone conference call with scientists from NOAA — the National Oceanic and Atmospheric Administration — and NASA — the National Aeronautics and Space Administration. The two agencies conducted independent analyses of their data, coming to the same conclusion about the record year of 2014.
Across the Earth, the average temperature in 2014 was 1.24 degrees Fahrenheit above the annual average of 57.0 degrees F, with records going back to 1880. That breaks the previous records of 2005 and 2010 by 0.07 degrees F. It’s also the 38th consecutive year that the annual global temperature was above average.
Since 1880, the Earth’s average surface temperature has warmed by about 1.4 degrees Fahrenheit, mostly driven by an increase in carbon dioxide and other greenhouse gases released into the atmosphere, the researchers said. Most of the warming has come since the 1980s.
Gavin Schmidt, director of NASA’s Goddard Institute of Space Studies, made this comment in a prepared statement:
“This is the latest in a series of warm years, in a series of warm decades. While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases.”
Although some skeptics have raised questions about whether global warming has been occurring in recent years, Schmidt said any short-term pause does not change the overall trend. In fact, the temperature rise seen for the past year fits perfectly onto a graph of the decades-long trend line for temperature rise.
Ocean conditions such as El Nino or La Nina can affect temperatures year-to-year, Schmidt said. Since these phenomena can cool or warm the tropical Pacific, they probably played a role in temporarily “flattening” the long-term warming trend over the past 15 years, he added, but last year’s record-breaking temperatures occurred during a “neutral” El Nino year.
This past year was the first time since 1990 that the global heat record was broken in the absence of El Nino conditions during the year. If El Nino conditions are present at the end of 2015, the researchers said the chances are high that the record will be broken again this year.
As I mentioned in yesterday’s post in Water Ways, strong regional differences were seen last year in the contiguous United States, with several western states experiencing record highs while the Midwest suffered through an abnormally cold winter. Other cold spots can be seen on the global map, but the hot spots more than balanced them out to break the heat record.
Much of the record warmth of the Earth can be attributed to record heat accumulated across the oceans. The average ocean temperature in 2014 was 1.03 degrees higher than the longterm average of 60.9 degrees, breaking previous records set in 1998 and 2003.
Record months for ocean temperatures were seen from May through November, with January through April each among the all-time top seven, while December was the third warmest December on record. The all-time monthly record was broken in June of last year, then broken again in August and again in September. Such sustained warmth in the ocean has not been seen since 1997-98 — during a strong El Nino.
On the land surface, the average temperature was 1.8 degrees higher than the long-term average of 47.3 degrees F, or the fourth highest average land temperature on record.
Europe is expected to report that 2014 was the warmest year in at least 500 years, according to information from the World Meteorological Organization. Last year surpasses the previous record set in 2007. Much of that warmth can be attributed to the second-warmest winter on record, followed by a record-warm spring.
According to the WMO report, 19 European countries have reported or are expected to report that last year was their hottest year on record. They Austria, Belgium, Croatia, the Czech Republic, Denmark, France, Germany, Hungary, Iceland, Italy, Luxembourg, The Netherlands, Norway, Poland, Serbia, Slovakia, Slovenia, Sweden, and the United Kingdom.
Around the world, precipitation was near average for 2014, the third year that near-average precipitation was measured for land-based stations.
The 10 warmest years on record, in order:
1. 2014, 1.24 degrees above average
2 (tie). 2010, 1.17 degrees above average
2 (tie). 2005, 1.17 degrees above average
4. 1998, 1.13 degrees above average
5 (tie). 2013, 1.12 degrees above average
5 (tie). 2003, 1.12 degrees above average
7. 2002, 1.10 degrees above average
8. 2006, 1.08 degrees above average
9 (tie). 2009, 1.06 degrees above average
9 (tie). 2007, 1.06 degrees above average
For further information, check out:
Global Analysis — Annual 2014 from NOAA, and
GISS Surface Temperature Analysis from NASA.