March 2017, global temperature update

March 2017, global temperature update

This is a quick update to my temperature graphs based on the latest NASA GISTEMP numbers. First, the monthly anomalies.


The March anomaly was 1.12C, the second-warmest March and the fourth-warmest month ever. In the absence of an El Niño, this is quite exceptional. I’ll leave it to the experts to explain why.

I have updated my prediction chart, based on extrapolating the first three months to the year-end average, based on past statistics.

Caveat! I caution readers to take this prediction with a grain of salt. I don’t understand physically why the first three-months average should overpredict the annual average. Also, in a reaction to last month’s post, Robert Rohde (added, see the update at the end of this post for some bad news about Robert’s health) of the Berkeley Research Group stated that this effect may be a statistical artefact.


The mean prediction is for a year-end average anomaly of 0.92C and a 95% confidence interval of 0.74-1.08C.  The average for the first three months of 2017 is 1.04C, higher than the 2016 record average of 0.98C.

Based on this analysis, the chance of 2017 setting a new annual record is 23%; second place, 51% and third place 23%; fourth or lower, 3%. Professional forecasters, taking account of physical processes like ENSO, will have different and better forecasts.

Here is the forecast in the context of annual mean anomalies since 1950.


And here is a plot showing temperature anomalies re-baselined to an approximate pre-industrial datum, with an added heavily-smoothed Loess line.


Extrapolating the Loess line to 2017 would yield a trend value anomaly of 1.08C. There’s an 87% chance that 2017 will come in above that line and very slightly increase the updated line’s gradient. If the present gradient is maintained, the trend will reach 1.5C before 2040 and 2C before 2090. Temperatures are likely to spike over those thresholds a decade or more before those dates. The future trend line could bend either way, downwards if we are successful with mitigation, or upwards if we are negligent and/or have some bad luck with carbon-cycle feedbacks.

Here is NASA’s global heat map, showing the huge hotspot in northern Eurasia, along with others in the western US and and western Antarctica.

mar17 nasa globe

On Twitter, Zeke Hausfather did some analysis on NOAA data, similar to what I did on the NASA data. He came up with broadly similar results, although he predicts a higher probability of 2017 setting a new annual record (his 48% for NOAA, versus my 23% for GISTEMP).  Note that the 2016 NOAA average anomaly was less of a stand-out record than GISTEMP’s. At the end of 2016, few people would have predicted that that year’s record could be broken in 2017. As Dylan sang “something’s happening here and you don’t know what it is, do you, Mr Jones?”

2017-04-20_18-08-36 zeke

Finally, here is a monthly anomaly graph of NOAA data posted by Joe Romm. It is colour-coded to show the different ENSO states. March 2017 was the warmest-ever month in an ENSO-neutral period.


Indeed, March 2017 was warmer than any El Niño month prior to the 2015-2016 event. Truly extraordinary.

Sou’s monthly update is always worth a read.

Update. I have just learned today that Robert Rohde has contracted blood cancer and is in need of funds to pay for part of his treatment as well as to help compensate him for loss of income during his months’ long chemotherapy session. I particularly appreciate Robert having taken the time to Tweet helpful criticism of my work here while he must have been undergoing a stressful diagnosis.

His Berkeley Earth colleague, Zeke Hausfather, has set up a fund-raising site for Robert. Please consider lending a helping hand.

Global temperature anomalies, 2016 and 2017

Global temperature anomalies, 2016 and 2017

I used to do regular monthly global surface temperature updates earlier this year, but I stopped a few months ago. I was getting bored with writing them and I noticed that readers weren’t reading them either. Also, Tamino and Sou do an excellent and timely job on this and I can add little to their commentary or figures.

Nevertheless, I do update my graphs regularly for myself and I thought I would do one last post to wrap up the year, even if all of the data are not yet in.


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Sensitivity training

This article was originally published online at Corporate Knights Magazine and will appear in the publication’s Fall 2016 hard-copy magazine. It was also previously republished, in part, at Skeptical Science.

Climate scientists are certain that human-caused emissions have increased carbon dioxide in the atmosphere by 44 per cent since the Industrial Revolution. Very few of them dispute that this has already caused average global temperatures to rise roughly 1 degree. Accompanying the warming is disruption to weather patterns, rising sea levels and increased ocean acidity. There is no doubt that further emissions will only make matters worse, possibly much worse. In a nutshell, that is the settled science on human-caused climate change.

What scientists cannot yet pin down is exactly how much warming we will get in the future. They do not know with precision how much a given quantity of emissions will lead to increased concentrations of greenhouse gases in the atmosphere. For climate impact it is the concentrations that matter, not the emissions. Up until now, 29 per cent of human emissions of carbon dioxide has been taken up by the oceans, 28 per cent has been absorbed by plant growth on land, and the remaining 43 per cent has accumulated in the atmosphere. Humans have increased carbon dioxide concentrations in the atmosphere from a pre-industrial level of 280 parts per million to over 400 today, a level not seen for millions of years.  Continue reading

¡Hasta la vista, el Niño! Surface temperature update for May 2016

¡Hasta la vista, el Niño! Surface temperature update for May 2016

The huge El Niño of 2015-2016 has now ended and global surface temperatures are now declining very quickly. In fact, the global temperature anomaly fall from February-May 2016 was 0.40°C; the biggest three-month decline since November 1928-February 1929 (0.48°C). Even the times of big volcanoes like Pinatubo did not see such rapid declines over any three-month period. This is surely a result of the extraordinary intensity of the now-departed El Niño.


Despite the rapid decline, May 2016 was the warmest May in the temperature record and had the highest temperature anomaly for any month in the record prior to October 2015. [Edit, this is not right, actually it was the second highest; January 2007 recorded an anomaly of 0.96 degrees, h/t Sou.] Nevertheless, the period of extraordinary record-breaking monthly records could well be over soon. All of the temperatures shown in this post are NASA’s GISTEMP data. Continue reading

No global warming since February 2016

No global warming since February 2016

Forgive the facetious, click-bait headline.

The NASA GISTEMP global temperature anomalies for March are now available. March 2016 had by far the largest temperature anomaly (1.28°C) for any March on record and the second highest anomaly for any month ever, beaten only by February 2016 (1.34°C), hence the snarky headline.

Here is the plot of month-by-month anomalies for recent warm years.


Clearly, my guesswork, what-if, forecast for the year is still running one-tenth of a degree cool. The NOAA forecast is for the El Niño to end in the next few months, with a rising probability of a La Niña forming in the latter half of the year. Continue reading

Temperature tantrums on the campaign trail

Temperature tantrums on the campaign trail

Originally published at Corporate Knights on March 17, 2016.

Sorry Ted Cruz. There’s no conspiracy among scientists to exaggerate global warming by fudging the numbers.

Last year was the warmest year recorded since the measurement of global surface temperatures began in the nineteenth century. The second-warmest year ever was 2014. Moreover, because of the persisting effects of the equatorial Pacific Ocean phenomenon known as El Niño, many experts are predicting that 2016 could set a new annual record. January and February have already set new monthly records, with February half a degree Celsius warmer than any February in history.

This news is deeply unsettling for those who care about the future of the planet. But it is even more upsetting for people opposed to climate mitigation, since it refutes their favourite talking point – that global warming has stalled in recent years.

U.S. Congressman Lamar Smith claims there has been a conspiracy among scientists to fudge the surface temperature records upwards and has demanded, by subpoena, to have scientists’ emails released.

Senator and presidential candidate Ted Cruz recently organized a Senate hearing on the temperature record in which he called upon carefully selected witnesses to testify that calculations of temperature made by satellite observations of the upper atmosphere are superior to measurements made by thermometers at the Earth’s surface.

It’s easy to cherry-pick data in order to bamboozle people. The process of making consistent temperature records from surface measurements and satellite observations is complicated and is easy to misrepresent.

But the fact remains that there are no conspiracies afoot. Here’s why. Continue reading

You can now run a MOOC at your own pace, from July 1

The Denial 101x MOOC (Massive Open Online Course) was a great success, with thousands of participants and many satisfied students. I admit that I was quite touched by the mostly positive student reactions and I am thankful to John Cook for inviting me to contribute to this course in a small way. This video compilation of students’ feedback shows how people from diverse backgrounds all got something from the course.

From July 1, 2015 onwards, the course is available for anyone to follow at their own pace. It’s completely free of charge, naturally!

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