The record closes on 2014. Was it the warmest year on record?

Summary: Alarmists trumpeted that 2014 was the warmest on record, seldom mentioning how long the record, or how much warmer, or if all the datasets agree. It’s innumeracy, an ignorance (sometimes feigned) of mathematics and the scientific method. It’s sad, since they’re repeating long-failed attempts to arouse public fear of climate change by statements beyond those of the climate science consensus — and often contradictory to it. (2nd of 2 posts today)

“It is extremely likely (95 – 100% certain) that human activities caused more than half of the observed increase in global mean surface temperature from 1951 to 2010.”
— conclusion of the IPCC’s AR5 Working Group I

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Contents

1. Appeals to fear. Will they work?
2. What do satellites tell us about global warming?
3. What’s the trend?
4. Who produces this satellite data & analysis?
5. For More Information

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(1) Appeals to fear. Will they work?

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Joe Romm at ThinkProgress is a poster child for the Left’s failure to build public support through propaganda. For an example see “2014 Was The Hottest Year On Record Globally By Far” — “The Japan Meteorological Agency (JMA) has announced that 2014 was the hottest year in more than 120 years of record-keeping — by far.”  Quite a bold statement, but not what JMA said.

The annual anomaly of the global average surface temperature in 2014 (i.e. the average of the near-surface air temperature over land and the SST) was +0.27°C above the 1981-2010 average (+0.63°C above the 20th century average), and was the warmest since 1891. On a longer time scale, global average surface temperatures have risen at a rate of about 0.70°C per century.

Five Warmest Years (Anomalies): 1st. 2014 (+0.27°C), 2nd. 1998 (+0.22°C), 3rd. 2013, {4th.} 2010 (+0.20°C), 5th. 2005 (+0.17°C).

No mention by JMA of “warmest by far”, since it was the warmest by only +0.05°C — far smaller than the accuracy of the hodge-podge global surface temperature network (run by individual national weather services, with widely varying funding and effort).

The world has warmed for 2 centuries, since WWII largely due to our emissions (natural cycles caused the warming from the early 19thC). Activists like Romm seldom mentioned how much it has warmed, which allows alarmists to more easily arouse fear. For the answer we turn to the NASA-funded global temperature data from satellites.  This post shows the numbers: the warming since 1979 is small (so far; the future might be quite different). The truth is out there for people willing to see it. Only with it can we prepare for our future.

Before we dive into the numbers, read this 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.

(2)  What do satellites tell us about global warming?

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Satellites provide the most comprehensive and reliable record of the atmosphere’s warming since 1979, measuring lower troposphere temperatures.

The 2014 Global Temperature Report
by the Earth System Science Center of the University of Alabama in Huntsville
(Blue is cold; red warm}. Click to enlarge.

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See a similar graph of the monthly data from the surface temperature stations of the Climate Anomaly Monitoring System (CAMS) of the Climate Prediction Center (CPC) at the U.S. National Centers for Environmental Prediction (NCEP).

The UAH report (prepared under contract for NASA), shows a world that has warmed since 1979, but only slightly. The global lower troposphere temperature trend starting in 16 November 1978 is +0.14°C  (0.3°F) per decade. What about 2014?

2014 was the third warmest year in the 36-year global satellite temperature record, but by such a small margin (0.01°C) as to be statistically similar to other recent years. 2014 was warm, but not special. The 0.01°C difference between 2014 and 2005, or the 0.02° difference with 2013 are not statistically different from zero. That might not be a very satisfying conclusion, but it is at least accurate.

The 2014 average temperature anomaly is also in keeping with temperatures since late 2001, when the global average temperature rose to a level that is generally warmer than the 30-year baseline average. The most recent 13 complete calendar years, from 2002 through 2014, have averaged 0.18°C (about 0.33°F) warmer than the 30-year baseline average, while the global temperature trend during that span was a warming trend at the rate of +0.05°C per decade — which is also statistically insignificant.

Warming in 2014 has not been uniform around the globe. The “coldest” was just south of Wilmar, Minnesota, 1.27°C (2.29°F) colder than usual. The “warmest” was south of the North Pole along the International Date Line, 1.65°C (about 2.97°F) warmer than usual. The UAH team computes anomalies using the World Meteorological Organization (WMO) recommended method, comparing the current temperatures vs. a 30 year base period ending with the latest decade.

Here are the 20 hottest years since 1979 (ranked by their anomaly, in °C). Note that the similar anomalies for most years after 2001.

1. 1998…..0.42°
2. 2010…..0.40°
3. 2014…..0.27°
4. 2005…..0.26°
5. 2013…..0.24°
6. 2002…..0.22°
7. 2009…..0.21°
8. 2007…..0.20°
9. 2003…..0.19°
10. 2006…..0.19°
11. 2012…..0.17°
12. 2011…..0.13°
13. 2004…..0.11°
14. 2001…..0.11°
15. 1991…..0.02°
16. 1987…..0.01°
17. 1995…..0.01°
18. 1988…..0.01°
19. 1980…..-0.01°
20. 2008…..-0.01°

Thanks to NASA’s prudence we have a second source for this data, prepared by Remote Sensing Systems (RSS) using different satellites and algorithms. They show that 2014 was the 6th warmest since 1979 (tied with 2007), only 0.26°C above the 30 year average, and not even close to the El Nino years of 1998 and 2010.
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(3) What’s the trend?

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The two satellite datasets show similar trends — as more roughly do the various surface temperature datasets — as documented in so many peer-reviewed studies. Two decades of cool weather, followed by almost 2 decades of warm weather. Wide swings in temperature; a relatively flat trend starting in 1998 – 2000.

(a)  By Roy Spencer: a graph of the full record of UAH satellite data (started in 1979).

Here’s another perspective on the UAH data:

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Here’s the RSS data:
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(4) Who produces the UAH satellite temperature data and analysis?

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About the global satellite data, from the November report:

As part of an ongoing joint project between UAHuntsville, NOAA and NASA, Christy and Dr. Roy Spencer, an ESSC principal scientist, use data gathered by advanced microwave sounding units on NOAA and NASA satellites to get accurate temperature readings for almost all regions on the Earth. This includes remote desert, ocean and rain forest areas where reliable climate data are not otherwise available.

The satellite based instruments measure the temperature of the atmosphere from the surface up to an altitude of about eight kilometers above sea level.

John R. Christy is Professor of Atmospheric Science at U Al-Huntsville, and Director of their Earth System Science Center (ESSC). He is also Alabama’s State Climatologis. See his full profile and publications here. Roy Spencer is a principal research scientist at the ESSC and member of the Affiliated Faculty at the U AL-Huntsville.

(5) For More Information

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(a)  Important articles about climate change:

1. Remote Sensing Systems’ explanation of recent temperature trends, how they differ from the models’ forecasts, and what this means.
2. “What’s the hottest Earth’s ever been?“, NOAA, 12 August 2014
3. “Why Do Different Satellite Datasets Produce Different Global Temperature Trends?“, Roy Spencer, 6 January 2014

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

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

(c)  An introduction to climate change:

1. What we know about our past climate, and its causes
2. Good news!  Global temperatures have stabilized, at least for now.
3. What can climate scientists tell about the drivers of future warming?
4. What can climate scientists tell us about the drivers of future warming?  – part two of two

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