A brief update for GISTEMP, whilst I try to get some more interesting posts completed.
I'm only updating a few data sets a month for now, as they are mostly pretty similar.
GISS Surface Temperature Analysis (GISTEMP) has March 2018, at 0.89°C above the base period of 1951 - 1980.
This is 0.1°C warmer than the anomaly for February.
It makes 2018 the 6th warmest March, with the last 4 Marches being 4 of the 6 warmest on record.
As is something of a theme so far for 2018 across all the data sets, March was close to the trend since 1970.
The average anomaly for the first 3 months of 2018 is 0.817°C.
My forecast for 2018 is 0.802 ±0.166°C, which is almost identical to the forecast from February.
This would put 2018 between the big gap between 2014 and 2015.
There is around a 74% chance of 2018 being the 4th warmest, and a greater than 99% likelihood of being between 7th and 2nd warmest.
Apologies for not updating this blog much recently.
I've been having more fun commenting on Watts Up With That, which I expect is a better use of my time as people actually read that blog.
I want to write some posts about some of the discussions there, but for the time being lets get back to charting global temperatures.
Note, I've skipped February's updates - none where particularly interesting being mostly slightly cooler than January, and this early in the year making little difference to the annual predictions.
UAH Temperatures
The global temperature anomaly according to The University of Alabama in Huntsville was 0.24°C, compared with the 1981-2010 base period.
This is the equal 6th warmest March in the data set.
This is a slightly higher anomaly than February, which was 0.2°C.
The start of 2018 continues to be slightly below the trend since 1979.
There's still little sign of a big La Niña drop, as happened after the 1998 El Niño.
Prediction
My statistical prediction based on the 3 months so far, and the trend is that 2018 will have an average anomaly of 0.243 ± 0.136°C.
This is up 0.01°C since last month.
An anomaly of 0.243°C would make this the 6th warmest year on record.
The probability spread suggests there is about a 28% chance of finishing in 6th place (ahead of 2002), and a similar chance of finishing 5th, ahead of 2015.
However, there is only a slim chance (less than 10%) of finishing 3rd or 4th, and virtually no chance of 2018 being the 2nd or 1st warmest.
There's about a 35% chance of finishing cooler than 2002, in which case it could finish just about anywhere as there are so many years with similar temperatures.
How much credence do I attach to these predictions?
If I'd posted last month I'd have said not much.
The predictions at this stage are heavily dominated by the trend and it seems likely that we are overdue a below the trend year, especially given the possibility of a La Niña.
However the small rise this month and the fact during the first quarter of the year anomalies have remained close to the trend, makes me slightly more confident that this prediction method might not be too far of this year.
I still expect it's more likely that we will finish below the mid-point prediction, but maybe not so far off.
All this will be bad news to those yearning for a return of the so-called pause.
At present even the lowest trend using Christopher Monckton's cherry picking exercise is for a trend of 0.72°C / century starting in July 1997.
A quick update on global temperatures for January 2018, focusing on surface data -
specifically that for NASA's GISTEMP, and the Met Office Hadley Centre HadCRUT.
Anomalies
GISTEMP gives the anomaly for January as 0.78°C, compared with the 1951-1980 base period.
This makes January 2018 the 5th warmest January in their data set.
HadCRUT gives the anomaly for January as 0.553°C, compared with the 1961 - 1990 base period.
This makes 2018 the 8th warmest January.
These graphs show the monthly data, a 12 month rolling average and the trend since 1970 (the period I use for the predictions).
They also show the current month as a red dot.
Comparisons
Here are all the anomalies for January 2018.
For each data set the temperature has been adjusted to show the anomaly against the common base period of 1981 - 2010.
GISTEMP
+0.325°C
HadCRUT
+0.229°C
NOAA
+0.260°C
BEST
+0.365°C
UAH 6
+0.260°C
RSS 4
+0.401°C
Predictions for 2018
As we only have one month so far these predictions are not likely to be too meaningful.
They are based on extrapolations from previous January figures, and a linear trend since 1970,
but as January only makes up 1/12 of the year, the predictions are going to be very close to simply looking at the linear trend.
As a result both predictions have 2018 finishing warmer than January, which seems unlikely.
The trend is probably inflated slightly by the recent succession of very hot years.
For GISTEMP the prediction is for 2018 to be 0.813 ± 0.139°C.
For HadCRUT the prediction for 2018 is 0.64 ± 0.156°C.
This post starts my ongoing monthly summaries of global temperature anomalies from different data sets.
In this I'll look at the two main satellite data sets - UAH 6, and RSS 4.
The anomalies (relative to their respective base periods) for January 2018 are
UAH 6: +0.26°C (Relative to 1981 - 2010)
RSS 4: +0.546°C (Relative to 1979 - 1998)
Translating RSS to the UAH base period would give RSS an anomaly of +0.401°C.
Both are cooler than December 2017 - UAH down 0.15°C, RSS down 0.044°C.
In the UAH set January 2018 is the 10th warmest January.
In the RSS set it is the 7th warmest.
These graphs show the monthly data across the satellite era, along with the trend and the 12 month moving average.
January 2018 is highlighted in red.
In both cases Janury 2018 is very close to the long term.
Forecasts
Using my simple statistical model, the predictions for 2018 are that UAH will have an annual anomaly of 0.256 ±0.185°C,
and that RSS will have an anomaly of 0.551 ± 0.167°C.
Note that in both cases the most likely prediction for 2018 is very close to the values for January.
This is to be expected given the the fact that January was very average.
But of course the uncertainty is large.
Predicting a specific ranking is probably foolish at this point, but both sets are looking to finish close to the current 5th warmest year of 2015.
UAH has around a 55% chance of finishing below 2015 and 45% above, whilst RSS has more or less equal chances of finishing above or below 2015.
If UAH finishes below 5th place, it could end up just about anywhere as there are a lot of years with very similar values.
It's unlikly to finish 1st or 2nd but there is around a 1 in 5 chance of UAH finishing 3rd or 4th.
For RSS there's a prety good chance (~40%) that it will finish between 2005 and 2015 for 6th place (owing to the big gap between the two), but only a slim chance (less than 10%) that it will finish below 6th.
Though if it does it could finish just about anywhere.
It has about a 1 in 7 chance of finishing 2nd.
As always these probabilities are based solely on past statistical inference and do not factor in the probability of a La Niña this year.
One Last Thing
As there will likely be a lot of talk of a returning pause as the next La Niña takes hold, it's worth seeing where we are in comparison to the previous powerful El Niño of 1998.
(What am I saying? There have been talk of a return of a pause since 2016.)
Anyway, this graph compares the 5 years surrounding 1998, with those surrounding 2016.
UAH 6 shows the least warming since 1998.
But even with that data set, whilst the peaks of the two El Niños are similar, the years before and after have been considerably warmer.
Christopher Monckton of Brenchley is back at Watt's Up With That with the first of what promises to be a series of articles about IPCC projections.
The article is
Tamper, tamper! How They failed to hide the gulf between predicted and observed warming
.
In it he revisits his usual argument that the rate of warming in the slowest warming data set (UAH 6) does not match the rate of warming predicted in the oldest IPCC report from 1990.
He also says that all the data sets have been tampered with -
in the article he objects to the changes to RSS 4, but in the comments he also says that the tampering charge applies to all data sets including UAH 6.
The only reason for using that particular data set was that it was the first to be released, and not because it happens to be the coolest.
He uses the oldest IPCC projections, by definition the least reliable, from 1990 and the slowest warming data set (UAH 6) to claim that there has only been half as much warming as predicted.
As Fig. 1 shows, in the 39 years 1 month from December 1978 to December 2017, the planet has warmed by half a Celsius degree.
But that is equivalent to 1.28 C°/century, or little more than one-third of the 3.3 C°/century predicted with
substantial confidence by IPCC in 1990 and also by the fifth-generation general-circulation models of the
Climate Model Intercomparison Project in 2013.
This is wrong on most counts.
He quotes the 1990 IPCC report as saying with substantial confidence a rate of warming of 3.3°C / century.
This figure does not appear in the report, and the figure they do state (0.3°C / decade) is not described as having substantial confidence.
What the report says is they have ... substantial confidence that models can predict at least the broad scale features of climate change.
(My emphasis.)
He also claims the latest IPCC projections are the same as those from the 1990s, but this is also wrong.
His 3.3°C / century warming is somewhere between two of the IPCC scenarios, but only for long term warming, up to the end of the century.
In the short term it says all scenarios are similar and projects between 0.3 and 0.7°C warming between 1995 and 2025 (using 20 year averages).
Using Monckton's trick of converting all warming projections to linear trends this is a rate of warming of between 1°C / century and 2.3°C / century.
Even UAH 6 is within these bounds.
But, what interests me most is where Monckton gets his 3.3°C / century figure from, and why this is faster than what he was claiming they said only a couple of years ago.
Back in May 2016 Monckton introduced the Global Warming Speedometer.
(Never to be seen again).
In this he claimed the 1990 IPCC report predicted a rate of warming of 2.8°C / century, with a lower bound of 1.9°C / century.
What the 1990 IPCC Report Said
The main description of future warming is made in page xxii of the first IPCC report.
They say that temperatures are likely to raise at a rate of 0.3°C / decade.
They then give figures for the amount of warming both from the pre-industrial period and the present (ie 1990).
They define the pre-industrial period as 1750-1800 (page 22) or just 1765 (page 177).
They state that by the the end of the century temperatures will be 4°C warmer than the pre-industrial period, and 3°C warmer from present.
They also say this will mean that by 2025 global temperatures will be 2°C warmer than pre-industrial levels, and 1°C from present temperatures.
This is illustrated with this graph, showing the likely warming and the upper and lower bounds.
However they define the pre-industrail period, it's clear from their figures and the graph that they consider there has been 1°C of warming from pre-industrail to 1990.
What's not clear is how precise these figures are meant to be, all temperature increases are given to whole degrees.
The projected 1°C by 2025 would translate to an average warming rate of 2.8°C / century, and this appear to be how Monckton calculated the rate for his speedometer,
although he credits this to page xxiv.
This is interesting as that page suggests a slower rate of warming.
Page xxiv quotes a projection of 1.8°C above pre-industrial levels by 2030.
Obviously this is less than the 2°C by 2025 they give on page xxii.
Taking this with the supposed 1°C warming up to present would suggest a projected 0.8°C warming over the 40 years from 1990 to 2030;
a rate of 2°C / century, with low and high estimates of 1.4°C and 3.0°C / century.
This would mean most data sets are well within the projected warming rates, and UAH 6 is only slightly below the lower estimate.
So why does Monckton believe that page xxiv is actually claiming a warming rate of 3.3 °C / century?
In response to a question from DWR54 he says,
In reply to the furtively anonymous “DWR54” p. xxiv of IPCC (1990) says:
“The numbers given below are based on high-resolution models,
scaled to be consistent with our best estimate of global mean warming of 1.8 C by 2030
[compared with pre-industrial temperatures] …
the numbers below should be reduced by 30% for the low estimate or increased by 50% for the high estimate.”
There had been 0.45 K global warming in the industrial era, so IPCC was predicting 1.35 K of warming over 4.1 decades, equivalent to 3.3 K/century.
In the passages cited by “DWR54”, IPCC rounded this value to 3 K.
His entire argument is based on the claim that there had only been 0.45°C warming from the pre-industrial period by 1990,
and that the IPCC were predicting an additional 1.35°C warming by 2030.
This does not agree with anything they say elsewhere and does not agree with their graph.
Here (in red) is what Monckton's 1.35°C of warming looks like.
Monckton's 0.45°C figure probably comes from page 199 of the IPCC report.
This is a chapter on instrument measurements, in which they say that the world is probably 0.45 ± 0.15°C warmer than the late 19th century.
There are many problems with Monckton using this figure.
For a start it isn't for warming from the pre-industrial period, but from the late 19th century.
Then there's the way he ignores the large uncertainty in the stated figure.
But the big problem is that whatever the merits of the 0.45°C figure, it isn't the one the IPCC used when they stated the warming rates from the pre-industrial period on pages xxii and xxiv.
You cannot simply take an unrelated figure from a different part of the report,
use it to add an extra 0.55°C to the expected warming and claim that's what the IPCC really meant - with substantial confidence.
In short - Monckton has literally made up a figure, and then quoted it as if it was a direct figure from the IPCC.
Monckton's Own Predictions
In commenting on Monckton's article I couldn't resist pointing out one of his own predictions, made in front of a congressional hearing in 2009.
He claimed then that global temperatures might only rise by 0.5°F by the end of the century,
that is about 0.28°C.
This means that by Monckton's own logic, temperatures are warming more than 4 times faster than his prediction, even using the slowest rising UAH data.
When I mentioned this in the comments, Monckton said he couldn't remember making such a prediction
In reply to Bellman, I do not recollect having predicted in 2009 that global warming would be only 0.25 K/century.
I said that at that time the warming rate was equivalent to 0.25 K/century.
I have published a series of papers in which the best estimate of warming is around 1.2-1.3 K/century.
That warming rate, and no higher rate, is consistent with the officially estimated net anthropogenic forcings in the industrial era.
His exact words, both in written and spoken testimony to congress, were
This century we may warm the world by half a Fahrenheit degree, if that.
It's not clear why he thinks the warming rate at the time was 0.25°C / century.
At the time he was saying there had been rapid cooling (but that's another story).
Possibly he did make a mistake both in his written and spoken testimony - elsewhere in the speech he suggests warming may be as much as 2°F by the end of the century.
But it does follow another habit of stating predictions with no indication of doubt.
For example in 2015 he said:
No warming has yet arisen this century.
Warming may be 0.6 K by 2100, could be as low as 0.4° K and will not exceed 1° K.
Now he's saying the most likely warming rate is 1.2 - 1.3 °C / century.
Yet he wants to hold the IPCC to account for projections made almost 30 years ago.
The Met Office Hadley Centre have released their HadCRUT4 data for December 2017.
Here is my monthly update describing what that means for the year, and looking at how well my forecast models performed over the year.
Temperatures
The HadCRUT anomaly for December 2017 was 0.585°C compared with the 1961 - 1990 base period.
This was the 6th warmest December in its record.
Five of the warmest seven Decembers have occurred in the last five years.
The other two where in 2003 and 2006, with the 2nd warmest being in 2006.
The mean anomaly for 2017 was 0.68°C, making 2017 the 3rd warmest year in the HadCRUT record.
The last four years have been the four warmest on record.
HadCRUT4 annual anomalies since 1979
HadCRUT4 annual anomalies since 1850
Forecast analysis
My prediction for 2017 based on data up to November would have been 0.680 ± 0.026°C.
The actual average for 2017 to 3 decimal places is 0.676°C.
This graph illustrates the changing predictions for each month, along with the 95% prediction interval.
This was not as good as for GISTEMP.
For much of the year the forecast was around 0.05°C too warm.
For HadCRUT the old model was better than the new, though the better confidence still suggests the newer model is better.
Final Thoughts
Both NOAA and BEST have also released their year end reports, with 2017 coming in respectively 3rd and 2nd warmest.
This means all of the main global temperature data sets, both surface and satellite, put 2017 as one of the three warmest years on record, with 2016 being the warmest.
What makes 2017 unusual is that it was not an El Niño year.
But although the last few years have been extraordinary in terms of the global temperatures, they should not come as a surprise.
They are not that unusual in relation to the trend seen since the 1970s.
A few years ago there was a run of years below the trend, now we have had a run of years above the trend line.
This is to be expected.
But they should be a shock to anyone who used a few cooler years to claim global warming had stopped at the start of the century.
We now have all the data for 2017 from all surface data sets, but I'll stick to the schedule of a single post for each set I'm tracking.
So this post will look at GISTEMP and there will be another looking at HadCRUT.
(And at some point I might get back to writing proper debunking posts.)
2017 from NASA
NASA's GISTEMP for December 2017 has been announced with a press release. This shows to little surprise that 2017 was the second warmest year in their data set, and also mentions that NOAA has it as 3rd warmest.
They also remind us that individual rankings of years are not that important, and the main message is that the long term trend is continuing.
December
The GISTEMP anomaly for December was 0.89°C, compared to the 1951-1980 base period.
This makes it the 2nd warmest December on record, with the last 4 years having the 4 warmest Decembers.
The mean anomaly for the year was 0.9°C, making 2017 the second warmest year in the GISTEMP record.
The last 4 years have been the 4 warmest on record.
Annual anomalies for GISTEMP since 1979.
Annual anomalies for GISTEMP since 1880.
Forecasts
Note - as always references to previous forecasts are based on recalculations using the latest data.
They may differ slightly to the published forecasts.
Based on data up to November I predicted that 2017 would be 0.892 ± 0.025°C.
The actual result was 0.897°C.
A difference of 0.005°C.
Here's how the forecast would have changed each month, compared to the actual annual value.
I'd say the GISTEMP forecasts were pretty successful.
They were always within 0.03°C of the actual annual figure.
For comparison, in March the average of the first three months was 1.067°C, my forecast would have been 0.915°C.
This graph compares the new and old models.
For most of the year the old model was better than the new.
After August there was little to choose between the two.
More importantly the confidence was much higher throughout.
As with the satellite data this should not be taken as too much evidence that the newer model is better.
As we will see the results are quite different for HadCRUT.
