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.


Continue reading

Global temperatures anomalies July 2016: still warmer than ever

The GISTEMP (NASA) data for July 2016 came out a few days ago and the records keep falling. July 2016 was warmer than any July on record by more than one-tenth of a degree..


That makes 10 months in a row of all-time monthly records, although June 2016 has now been revised down by one-hundredth of a degree to give a tie with June 2015. July anomalies are now close to my guesswork from the start of the year. I underestimated the January-March El Niño warmth and did not expect the rapid decline from March to June. My updated guess for the 2016 annual anomaly is now 0.96°C, a big jump from 2015’s 0.87°C. For 2016 not to be a record, temperature anomalies for the rest of the year would have to average below 0.61°C, something that hasn’t happened since 2008. Year-to-date average anomalies are 1.06°C. Continue reading

June 2016 surface temperatures break monthly record, but not by much

June 2016 surface temperatures break monthly record, but not by much

NASA has released its global surface temperature anomaly calculation for June 2016 and it sets a new record for June. June 2016 had an anomaly of 0.79°C, edging out the previous record from June 2015 (0.78°C) and the previous record from June 1998( 0.77°C). As the mighty El Niño of 2015/2016 has ended, no longer are monthly temperature anomalies setting blockbuster records, mere records are all we are left with. The string of monthly records now extends to nine and may continue for a few more.


The four-month decline from February to June was 0.54°C, the largest four-month decline on record. (The second-largest decline, since you ask, was 0.52°C from August to December 1916.)

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