2010 – The Hottest Year on Record: Is this a Cause for Concern?

GISS report that 2010 has tied with 2005 as being the hottest year on record. James Hansen, the director of GISS, said that, “If the warming trend continues, as is expected, if greenhouse gases continue to increase, the 2010 record will not stand for long.”

Is this a cause for concern?

GISS Data Compared with Hansen’s Scenarios (2006)

The GISS Land Ocean Temperature Index (LOTI) data up to January 2011 are shown in Figure 1. They are compared with the global warming models presented by Hansen (2006).


Figure 1: Scenarios A, B and C Compared with Measured GISS Land-Ocean Temperature Index (after Hansen, 2006)

The blue line in Figure 1 denotes the GISS LOTI data and Scenarios A, B and C describe various CO2 emission outcomes. Scenarios A and C are upper and lower bounds. Scenario A is “on the high side of reality” with an exponential increase in emissions. Scenario C has “a drastic curtailment of emissions”, with no increase in emissions after 2000. Scenario B is described as “most plausible” which is expected to be closest to reality. The original diagram can be found in Hansen (2006). It is interesting to note that, in his testimony to US Congress, Hansen (1988) describes Scenario A as “business as usual”, which somewhat contradicts his “on the high side of reality” statement in 2006.

It is evident from Figure 1 that the best fit for actual temperature measurements is currently the emissions-held-at-year-2000-level Scenario C. The current temperature anomaly is 0.61  °C. Therefore, even with temperatures at record highs, we are not experiencing the runaway temperatures predicted for the “business-as-usual” Scenario A. Indeed, for Scenario C with emissions curtailed at year-2000 levels, the rate of temperature increase is an insignificant 0.01 °C/decade.

It is also worth noting that we are currently at the lower end of the range of estimated temperatures for the Holocene optimum and the prior interglacial period. These occurred without human intervention or huge increases in carbon dioxide.

HadCRUT3 Compared with IPCC AR4

The above comparison based on Hansen (2006) uses relatively old climate models. Therefore, I have compared current HadCRUT3 temperature data with the latest IPPC AR4 (2007) models in Figure 2.

Figure 2: IPCC Scenarios A1B, A2 & B1 Compared with HadCRUT3 Temperature Data (after AR4, 2007)

Figure 2, which is based on IPCC AR4 Figure TS.26. I have added the HadCRUT3 data as blue dots. The black dots in the original TS.26 diagram appear to be HadCRUT3 data but are slightly misaligned. Therefore, I offset the HadCRUT3 data by adding 0.018°C to achieve a reasonable fit with the individual data points shown in AR4. The blue line with white dots the smoothed HadCRUT3 data. It is evident from Figure 2 that the smoothed curve gives an excellent fit with observed data presented as the solid black line in AR4. The current temperature anomaly is 0.52  °C.

The observed temperature trends in Figure 2 are significantly below the “likely” warming scenarios presented in AR4. Furthermore, as with the GISS data, the current HadCRUT3 trend is similar to the emissions-held-at-year-2000-level scenario.

Conclusions

Two comparisons are presented that compare GISS LOTI data and HadCRUT3 data with their respective temperature simulation models and the following conclusions are offered:

  1. Observed temperatures are significantly below the “most plausible” or “likely” high emissions scenarios. Instead, they are on a trajectory that is similar to the emissions-held-at-year-2000-level scenarios.
  2. Current temperatures are at the lower end of the range of estimated temperatures for the Holocene optimum and the prior interglacial period. These temperatures occurred without human intervention.

In summary, global temperatures may be reaching record highs but they are not following “runaway” trajectories suggested by computer models. Instead, they are following an insignificant warming trend of approximately 0.01 °C/decade.

Notwithstanding the above, it should be noted that time period for the comparison of actual temperature measurements with those predicted by computer models is still relatively short. Hansen (2006) suggests that we could expect reasonable results for distinction between the scenarios and useful comparison with the real world by 2015.

Response to #203 in Deltoid

Re #203

I see McFarlane still wants to waste his time and avoids looking up the measurements of cosmic rays for the past 40 years….I’ll point out one graph of cosmic ray flux here that shows no long term trend over the past 55 years. He still doesn’t seem to get it. Even if cosmic rays could influence climate (which is extremely unlikely anyway), they’re not going to change the climate because they’re not changing themselves. A few fringe scientists don’t change the rules of logic.

A Few Fringe Scientists?

A CERN press release here in 2006 describes the CLOUD experiment.

The goal of this experiment is to investigate the possible influence of galactic cosmic rays on Earth’s clouds and climate. It involves an interdisciplinary team comprising 18 institutes from 9 countries including USA and Russia.
This should answer Chris’s comment on “a few fringe scientists”.

Correlation between Recent Temperature Changes & Cosmic Rays
The cosmic ray fluctuation shown in Chris’s link is virtually identical to that shown in Fig 29 of the ISAC report here. I include a cut-down version of the ISAC diagram here for ease of reference.

It is evident that, by using data identical to that supplied by Chris, ISAC produce a very good correlation between temperatures and cosmic ray fluctuations. However, the ISAC conclusion is the opposite from that suggested by Chris.

Contrary to Chris’s claim that cosmic rays are not changing and therefore cannot cause a climate change; ISAC concludes that small changes in cosmic rays lead to large changes in the Earth’s climate.

Furthermore, ISAC cites many robust statistical correlations and a large number of pertinent references to validate their conclusion. Nevertheless, ISAC also highlights that the physical mechanisms of the solar-activity/cosmic-ray/climate correlation are poorly understood; hence the need for experimental verification, such as those being undertaken out at CLOUD and SKY.

Is this not the way that science works? Postulate a hypothesis. Test it by experiment. Prove it, improve it, or disprove it. Then move on.

Only time will tell if the cosmic-ray hypothesis is valid. It is currently at the test-it-by-experiment stage. Nonetheless, the research is being carried out by many respectable institutions and they are using valid scientific methodology. Consequently, it ill behoves Chris, or anyone else, to label this research as “fantasy land”

Hansen’s 1988 Climate Models: Response to Julien in Deltoid 2 August 2008

In Deltoid #203 on 29 July 2008 Julien Emile-Geay wrote:

It is simply astounding how climate skeptics have gotten cornered into such a tiny fraction of disinformation space that they must exhume 20-year old models to vainly poke holes into the current scientific literature.

Hence, McIntyre and his clique can’t get over Mann Bradley and Hughes (1998, 10 years old), and a lot of those who have no clue about GCMs think it’s fair game to throw dirt at Hansen’s GISS model predictions (1988). Meanwhile climate scientists have moved on : some results have survived, some have not, but the basic result remains – AGW is real, no amount of disingenuous PR will make it go away.

Given the simplicity and low resolution of Hansen’s 1998 model (which didn’t have anything remotely close to an ENSO, for instance), it is indeed remarkable that it was able to predict the temperature of the next 20 years to such accuracy. What the Skeptics keep missing (Mr McFarlane in particular) is that numerical modeling and computer power have done quite a bit of progress in the past 20 years, and no climate scientist is retarded enough to be hanging their hat over 1988 results.

Sure, there still are legitimate questions concerning the relative importance of natural vs anthropogenic climate variability, some of which have implications for policy initiatives, and that would deserve healthy debate. Yet the Skeptics are so blinded by their political prejudices that they keep fighting old windmills.

I can’t speak for every climate scientist, but the only reason why I’d ever show the Hansen 1988 figures at this day and age would be to demonstrate that the physics of greenhouse warming are rather basic (indeed, Arrhenius)
had figured it out over a century ago), and that a good radiative transfer code (which is what the GISS model is known for) is enough to produce credible global temperature trends given a realistic forcing.

Current GCMs are now focused on getting the regional scales right – that’s where the money is, and intelligent skeptics (I heard there were some) would be well inspired to get out of their rut and on board that train. If they keep whining at the 1988 stop we soon won’t be able to hear them.

So, now that we’ve got that one cleared, can we please talk about something more interesting ? Abrupt climate change, operational climate prediction, regional climate variability, link with tropical cyclones, to name a few…

Or is it that there just isn’t any stone left for the AGW skeptics to hide ?

My response on 2 August 2008 was:


Wow Julien! So many comments in such a brief response, but, unfortunately, liberally sprinkled with remarks such as disinformation, disingenuous, retarded, prejudices, etc. Nevertheless, I shall try to respond in a more rational manner.

Exhumation of 20-Year Old Models

It is simply astounding how climate skeptics have gotten cornered into such a tiny fraction of disinformation space that they must exhume 20-year old models to vainly poke holes into the current scientific literature.

If you read my posts above it is clear that I didn’t exhume Hansen’s 1988 model. Jim Hansen did. Furthermore, he published his models here in 2006 and stated here in 2006 that Scenario B “was dead on the money”. In addition, Tim Lambert said in #47 in this blog that:

Scenarios B and C don’t diverge until after 2006. Results so far are close to both B and C. In a few more years we’ll see if temperatures now stabilise (scenario C) or continue to increase (scenario B).

I agree with Tim, but my chart below shows that what looked to be a reasonable fit with Scenario B in 2006 does not look very good in 2008.

I reiterate my statement in #195, that:

It is early days yet, but it would appear that our planet is following the zero-emissions Scenario C.

From the foregoing, I contend that it is reasonable for me to comment on Hansen’s 2006 papers and posts in this blog without being accused of exhuming 20-year old models. Julien, perhaps you should target your responses at Jim Hansen. He was responsible for the initial exhumation of his 20-year old models.

Mann, Bradley & Hughes 1998 [MBH98]

I thought that McIntyre & McKitrick (M&M) did a well-balanced due-diligence on MBH98. Furthermore, despite more recent papers from the “Hockey Team” over the last 10 years, it would appear that M&M’s core conclusions still stand, namely: “no bristlecones, no hockey stick”.

Incidentally, the MBH98/M&M discourse was one of the reasons why I began to doubt the AGW hypothesis.

AGW is Real

AGW is real, no amount of disingenuous PR will make it go away.

Perhaps, but AGW is still currently a hypothesis. It has not yet been raised to a law of physics.

ENSO

Thank you for the Wikipedia link, but I didn’t need it. Nevertheless, I was half expecting a response stating that one of the reasons for the temperature drop in 2008 was that 2007-2008 was a La Nina.

Computer Power

A large part of my day job involves running complicated computer models and, therefore, I am well aware of the increased computational power available and the evolution of current GCMs. However, the GCMs that I am aware of “…don’t do clouds very well”, which may lead to incorrect temperature predictions.

Retarded Climate Scientists

… no climate scientist is retarded enough to be hanging their hat over 1988 results

I wouldn’t call Jim Hansen retarded for exhuming his 1998 model, but, if you so wish; it is your choice.

Arrhenius

I can’t speak for every climate scientist, but the only reason why I’d ever show the Hansen 1988 figures at this day and age would be to demonstrate that the physics of greenhouse warming are rather basic (indeed, Arrhenius)

I am well aware of Arrhenius’s work, but it would appear that this one should also be sent to Jim Hansen, because it refers to his exhumation of his 1988 models.

Other Topics

…can we please talk about something more interesting ? Abrupt climate change, operational climate prediction, regional climate variability, link with tropical cyclones, to name a few…

I agree. In 2007, my company employed Weather Intelligence, UK, to carry out research for us on regional climate variability and operational climate prediction.

Importance of Hansen’s Models

Chris O’Neill said on Deltiod

Gee, and I thought that twenty year old model was the be-all and end-all of climate forecasting.

My respnose was:

Chris, Hansen’s 20-yer old models presented in #109 are very important. They  are the  cornerstone of IPCC/your government policy. If they are wrong then your government is going the wrong way on CO2.

Yet in 2006 Hansen said here that Scenario B “was dead on the money”. It would now appear that he was wrong. Planet Earth appears to be tracking below the zero-emmissions Scenario C and Scenario B is not “dead on the money”; it is way too high.

GISS Temperature Data January-June 2008

Eli Rabbett re #192 on Deltioid wrote that

“This is the one with January standing for all of 2008”.

My response to Eli was that I stated that the temperature figures were for the first six months of the year. You can check the GISS surface station figures here or the land ocean data here.

I summarise the GISS Jan-Jun 2008 figures below for ease of reference:

GISS Temperature Data 

2008      Land       Land-
         Stations      Ocean

Jan               35             14
Feb               32             25
Mar               72             60
Apr               52             42
May              45             39
Jun               26             26
Average = 44           34

Note: 

  1. Surface Station Data Jan-Jun 2008 average = 0.44 °C.
  2. Land-Ocean Data Jan-Jun 2008 average = 0.34 °C.

The latest figures are well below my original Jan-May graph posted in Deltoid #190. It is evident from my graph, and the latest GISS figures, that the 2008 temperatures will be significantly below recent temperatures. They will probably be as low as 1995 or even, God forbid, 1990! It would appear that our planet is currently tracking below Hansen’s Zero-Emissions Scenario C. Good old planet Earth!

I reiterate, is it possible that a stabilisation of temperatures and/or global cooling, as predicted by the solar-cycle/cosmic-ray fraternity, is beginning to happen?

Eli, I look forward to your response.