Was 2014 the warmest year? NOAA says that was “more unlikely than likely”.

Summary: To learn if 2014 was the warmest year let’s read the annual reports of NOAA and NASA. They give clear answers (different from the headlines). It might have been the warmest, but if so, only by a insignificant amount. The hysteria of activists about this is absurd. The data shows that the pause continues.

1. Last year was 0.04°C (0.07°F) warmer than 2005 according to NOAA’s surface temperature data (0.02°C per NASA). NOAA gives it a 48% probability of being the warmest of the past 135 years (a 38% probability per NASA ). NOAA describes this as meaning “more unlikely than likely”.
2. Berkeley Earth’s data shows it as tied with 2005 and 2010 (within the margin of error).
3. Neither of NASA’s two satellite datasets of lower troposphere temperature show it as close to a record (data back to 1979).

Before we jump into the details, here’s a cautionary note from Colin Morice (climate monitoring scientist at the UK Met Office):

Record or near-record years are interesting, but the ranking of individual years should be treated with some caution because the uncertainties in the data are larger than the differences between the top ranked years. We can say this year will add to the set of near-record temperatures we have seen over the last decade.

Contents

1. How warm was 2014?
2. How certain is the result?
3. The Berkeley Group looks at 2014.
4. Update: the UK Met Office
5. The satellites disagree with the “hottest year” story.
6. Conclusions
7. Other articles about the warmest year
8. For More Information

(1)  How warm was 2014?

“The Most Dishonest Year on Record“, Robert Tracinski, The Federalist, 19 January 2015 — Excerpt:

If 2014 is supposed to be “hotter” than previous years, it’s important to ask: by how much? You can spend a long time searching through press reports to get an actual number on this — which is a scandal unto itself. Just saying one year was “hotter” or “the hottest” is a vague qualitative description. It isn’t science. Science runs on numbers. You haven’t said anything that is scientifically meaningful until you state how much warmer this year was compared to previous years — and until you give the margin of error of that measurement.

The original NASA press release did not give those figures — and most press reports just ran with it anyway. This in itself says a lot. When it comes to global warming, “journalism” has come to mean: “copying press releases from government agencies.”

That’s our journalists! But annual reports by NASA (who runs the GISS dataset) and NOAA (runs the NCDC dataset) provide the answers for journalists interested in news rather than the pack’s narrative. For answers let’s first turn to NOAA’s 2015 “State of the Climate” report. From the Global Analysis section:

The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880. The annually-averaged temperature was 0.69°C (1.24°F) above the 20th century average of 13.9°C (57.0°F), easily breaking the previous records of 2005 and 2010 by 0.04°C (0.07°F).

So the fireworks are about a temperature increase of 0.04°C (0.07°F) over 7 years?

(2)  How certain is the result?

How certain is NOAA of this conclusion? We turn to the section Calculating the Probability of Rankings for 2014:

Evaluating the temperature of the entire planet has an inherent level of uncertainty. The reported global value is not an exact measurement; instead it is the central value within some range of possible values. The size of this range depends on the method used to evaluate the global temperature anomaly, the number and placement of the stations used in the analysis, and so on. … Scientists, statisticians and mathematicians have several terms for this concept, such as “precision”, “margin of error” or “confidence interval”.

NOAA provides the margin for error of the 2014 average: +0.69°C ± 0.09 (+1.24°F ± 0.16). The increase over the previous record (0.04°C ) is less than the margin of error (±0.09°C). That gives 2014 a probability of 48% of being the warmest of the 135 years on record, and 90.4% of being among the five warmest years. They even explain how to describe those odds: “more unlikely than likely“. That’s why so many climate scientists study what they call the “pause” or “hiatus”.

The NASA-NOAA “Annual Global Analysis for 2014” comes to conclusions similar to NOAA’s. It shows the probability that 2014 was the warmest year as 38%.  (The graph on page 6 clearly shows the pause in surface atmosphere warming since ~1998).

(3)  The Berkeley Group looks at 2014.

“The Average Temperature of 2014“, 14 January 2015 — Conclusion:

The global surface temperature average (land and sea) for 2014 was nominally the warmest since the global instrumental record began in 1850; however, within the margin of error, it is tied with 2005 and 2010 and so we can’t be certain it set a new record.

(4)  Update: the UK Met Office

“2014 one of the warmest years on record globally” — UK Met Office, 26 January 2015 — “Provisional full-year global mean temperature figures show 2014 was one of the warmest years in a record dating back to 1850.”

The  HadCRUT4 dataset (compiled by the Met Office and the University of East Anglia’s Climatic Research Unit) shows last year was 0.56C (±0.1C*) above the long-term (1961-1990) average. Nominally this ranks 2014 as the joint warmest year in the record, tied with 2010, but the uncertainty ranges mean it’s not possible to definitively say which of several recent years was the warmest.

Colin Morice, a climate monitoring scientist at the Met Office, said: “Uncertainties in the estimates of global temperature are larger than the differences between the warmest years. This limits what we can say about rankings of individual years. “We can say with confidence that 2014 is one of ten warmest years in the series and that it adds to the set of near-record temperatures we have seen over the last two decades.”

(5)  The satellites disagree with the “hottest year” story.

NASA funds two satellite datasets of lower troposphere temperatures. They have better spacial coverage than the surface temperature data, and far better consistency.  The NASA-NOAA annual report (page 6) says that the RRS data shows 2014 as the 6th warmest since 1979 (tied with 2007); the UAH data shows it as the 3rd warmest (below the El Nino years of 1998 and 2010).

For more details see The record closes on 2014. Was it the warmest year on record?, 7 January 2015.

(6) Conclusions

“The real climate battle after a sweltering 2014”
— Jeffrey Sachs (economist, Director of the Earth Institute at Columbia), 18 January 2015

The press releases of NOAA and NASA failed to mention the satellite data and its recent divergence from the surface temperature trend. Journalists failed to report the key details in the NOAA and NASA reports. Activists exaggerated (“sweltering”!), seeking to whip up hysteria.

The result is a major failure in coverage of this vital issue, justifying the public’s low confidence in the press and journalism.

(7)  Other articles about the warmest year

Several people quickly saw through journalists “warmest year” exaggerations:

1. “NASA climate scientists: We said 2014 was the warmest year on record, but we’re only 38% sure we were right“, David Rose, The Mail, 17 January 2015.
2. “NOAA, NASA: 2014 was probably not the warmest year on our record“, Luboš Motl, The Reference Frame, 19 January 2015.
3. “Scientific Consensus that 2014 was record Hottest year? NO.“, The Register, 19 January 2015.

(8)  For More Information

(a)  Reference Pages about climate on the FM sites:

1. The important things to know about global warming.
2. Posts about the pause.
3. My posts about climate change.
4. Studies & reports, by subject.
5. The history of climate fears.

(b)  Other posts about the hottest year:

1. 2014 will be the hottest year on record! Except for the details, which ruin that narrative., 4 December 2014.
2. The record closes on 2014. Was it the warmest year on record?, 7 January 2015.