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

NASA January 2016 temperature update

The NASA GISTEMP global average surface temperature data have been updated to include January 2016, which had the largest monthly temperature anomaly ever recorded: 1.13°Celsius above the 1951-1980 baseline. This is slightly above the  December 2015 anomaly of 1.11°C.


The graph shows month-by-month anomalies for selected warm years. In addition, I have added my guess for how monthly temperatures might trend over the year. This is not an expert forecast and I have done it just to calculate what the annual surface temperature for 2016 would be if that trajectory were followed. Basically, I have assumed that the elevated temperature attributable to the big El Niño will persist until May and will drop off until September. My guess is that the annual anomaly for 2016 will be 0.93°C, 0.07°C higher than 2015. This is shown by the orange dot in the graph below. Continue reading

A global temperature record for 2015

A global temperature record for 2015

The 2015 data are now in for Nasa’s GISTEMP surface temperature record. (News release, slides, data.) As expected, 2015 is the warmest year in the series. By far. The two warmest years in recorded global history were 2014 and 2015. Fifteen of the sixteen warmest years on record have occurred since 2001. December 2015 was the warmest month ever recorded.


The smooth lines are 42-point and 12-point Loess filter calculations. I defy anyone to identify the much-ballyhooed “pause”.

According to Britain’s Met Office, 2016 is likely to be warmer still. The increase from 2015 t0 2016 is likely to be as big as the jump from 2014 to 2015.

2016-01-05_18-23-14If this happens, it will be the first time ever in the history of global surface thermometer records that there were three years of consecutive new records. Even if 2016 turns out to be a little cooler than the Met Office forecast, it is very likely that by this time next year the three warmest years since global measurements began will be 2014, 2015 and 2016, in some order or other. Continue reading

NASA October temperature update: a new monthly record

Wow. Just in time for Paris.

My guesswork now looks a little lame as the Nasa October land-ocean temperature anomaly shoots upwards to a new record of 1.04 degrees Celsius.


Monthly anomalies for selected hot years since 1998. My guesswork forecasts are shown in dashed and dotted lines. Data from NASA.

A clear all-time temperature record for 2015 is now assured, because November and December anomalies would now have to be less than 0.34 degrees, a level not seen for those months since 2000, for 2014 to retain the warmest year record.

My original anomaly forecast for the year was 0.82 degrees C , which is unchanged below, but is clearly now conservative and is shown  by the red square. The red cross (0.86 degrees C) is a projection based on November and December averaging the same anomaly as October.2015-11-16_17-41-51

As Michael Caine put it: Continue reading

2015 and 2016 global temperatures: a “what-if” exercise

It’s hardly news to predict that 2015 is almost certain to break the global surface temperature record.


The data in this graph are the latest NASA GISS monthly temperature anomalies (1951-1980 baseline), shown in solid lines, while the dashed and dotted lines are from the hitherto little-known future temperature series known as ANDY GUESS, updated in July 2015. I’m not attempting any serious forecasting here, just indulging in a what-if exercise. Note that my starting point in July is a little above the actual GISS value, for that month, this is because NASA subsequently tweaked their data a little. I have just selected a few recent hot years for comparison in this graph.

Basically, I have assumed that the current El Niño will persist until the end of the year, that its effects on global temperatures will lag by six months or so and that this El Niño will run a little hotter than recent ones. I just wanted to see how these guesses would play out for average global temperatures in 2015 and 2016.  The result is shown below.

Continue reading