Electricity Generation: Wind Power is more Than Twice the Cost of Coal

                                                               Cartoon by Josh cartoonsbyjosh.com

Proponents of renewable energy often cite GenCost 2018 to argue that wind power is now less costly than coal-fired power. However, inspection of GenCost 2018 shows that not all of the costs of electricity generation are included in its estimate of the Levelised Cost of Electricity (LCOE). The LCOE presented in GenCost 2018 is effectively the “farm-gate” cost of energy, i.e., the price required by the generator to break even at its site of generation.

In a similar manner to the “farm-gate” cost of milk, the GenCost 2108 LCOE does not represent the final price to the consumer, since it fails to include the cost of transportation (transmission lines). GenCost 2018 also does not include the cost of power plant degradation and demolition, etc. These (omitted) costs are not insignificant as explained below:

  1. GenCost 2018 uses it uses very high capacity factors for wind (from 38% to 44%), whereas real-world capacity factors are in the range 33% to 38% or lower. For example, Rutovitz et al (2017) state that wind farms in Australia have an average capacity factor of 33% and GHD (2018) assumes a 38% capacity factor. Reducing the capacity factor from 44% to 33% increases the LCOE for wind by approximately 33%.
  2. GenCost 2018 does not include degradation in performance with time, which is estimated to be 1.6% per annum (Staffell & Green, 2014). Including the loss in performance increases the LCOE for wind by approximately 20%.
  3. GenCost 2018 uses a design life of 25 years but, typically, wind turbines do not last longer than 20 years (Coultate & Hornemann, 2018) and Hughes (2012) suggests a 15-year economic life for wind turbines. Reducing the design life from 25 years to 20 years increases the LCOE for wind by approximately 8%.
  4. GenCost 2018 neglects the cost of transmission lines and demolition, which are usually higher for renewables than for coal-fired power. Including the costs of transmission and demolition increases the LCOE for wind by an average of 35%.

Including all of the items listed in (1) to (4) above more than doubles the GenCost 2018 LCOE for wind power as shown in Figure 1.

These costs should be included in the GenCost 2018 LCOE calculation if an accurate comparison with other sources of power is to be made.

Figure 1:  Comparison of GenCost 2018 LCOE’s with Real-world LCOE (i.e., when the Cost of Transmission Lines, Demolition, etc., are Included), Source: McFarlane (2019)

It is evident from Figure 1(b) that:

  1. The cost of wind power (with 6 hours storage) is approximately 2½ to 3¼ times the cost of existing coal power and approximately 2 to 2½ times the cost of new coal power.
  2. The cost of standalone wind power (with no storage) is approximately 1½ to 2 times the cost of existing coal power and approximately 1¼ to 1½ times the cost of new coal power. However, no storage would incur the additional cost of back-up by fossil-fuel plants.

It should be emphasised that the real-world LCOE values for standalone wind presented in Figure 1(b) are verified by Stock et al (2016), which presents reverse auction values for wind power in ACT that are in the $73 to $92 per MWh range. This range compares well with the $79 to $95 per MWh range for the real-world values presented in Figure 1(b) above, which gives confidence in the accuracy of the real-world LCOE estimates presented in this review.

Furthermore, the conclusion from Figure 1(b) that wind power is more expensive than conventional generation is corroborated by the fact that real-world experience shows that those countries with the highest generation from renewables also have the highest electricity costs as shown in Figure 2.

Figure 2:  Cost of Residential Electricity Compared with Installed Capacity of Renewables (after MacDonald, 2018)

It is evident from Figure 2 that those countries with the highest penetration of renewable electricity (Germany and Denmark) have the highest electricity costs, which leads to the obvious conclusion that renewables are more costly than conventional generation.

In summary, it is shown that the levelised cost of electricity generated by wind power is significantly more expensive than coal-fired power (by a factor of 2 to 3).

Therefore, it is recommended that any new generation capacity in Australia should include coal-fired power, not only because it is cheaper than wind but also because it is more reliable and provides power on an as-needed basis.


Brailsford et al, 2018, Powering Progress: States Renewable Energy Race, Louis Brailsford, Andrew Stock, Greg Bourne and Petra Stock, published by Climate Council of Australia Ltd 2018


Coultate & Hornemann, 2018, Why wind-turbine gearboxes fail to hit the 20-year mark, The Renewable Energy Handbook (Wind), 2018

GenCost 2018, Graham, P.W., Hayward, J, Foster, J., Story and Havas, L., 2018, GenCost 2018 CSIRO, Australia


Hughes, 2012, The Performance of Wind Farms in the United Kingdom and Denmark, Published by the Renewable Energy Foundation


MacDonald, 2018, A Look at Impacts of Wind and Solar Electric Generation on Electricity Price, Energy Performance Measurement Institute (EPMI)

McFarlane, 2019, Levelised Cost of Electricity: A Comparison between Wind and Coal Power


Rutovitz et al, 2017, Rutovitz, J., McIntosh, B., Morris, T. and Nagrath, K. (2017) Wind Power in Australia: Quick Facts. Prepared for the Climate Media Centre and Australian Wind Alliance by the Institute for Sustainable Futures, UTS

Click to access 2017_Wind_Power_in_Australia_ISF.pdf

Staffell & Green, 2014, How does wind farm performance decline with age? Renewable Energy


Stock et al, 2016, Territory trailblazer: How the ACT became the renewable capital of Australia, published by the Climate Council of Australia Limited

The 1970s Global Cooling Consensus was not a Myth


This is a repost from my article in WUWT. Figures 1 and 2 have been added to the post because they were missed out in WUWT.

Purpose of Review

Whether or not there was a global cooling consensus in the 1970s is important in climate science because, if there were a cooling consensus (which subsequently proved to be wrong) then it would question the legitimacy of consensus in science. In particular, the validity of the 97% consensus on global warming alleged by Cook et al (2013) would be implausible. That is, if consensus climate scientists were wrong in the 1970s then they could be wrong now.

It is not the purpose of this review to question the rights or wrongs of the methodology of the 97% consensus. For-and-against arguments are presented in several peer-reviewed papers and non-peer-reviewed weblogs. The purpose of this review is to establish if there were a consensus in the 1970s and, if so, was this consensus cooling or warming?

In their 2008 paper, The Myth of the 1970s Global Cooling Scientific Consensus, Peterson, Connolley and Fleck (hereinafter PCF-08) state that, “There was no scientific consensus in the 1970s that the Earth was headed into an imminent ice age. Indeed, the possibility of anthropogenic warming dominated the peer-reviewed literature even then.” This conclusion intrigued me because, when I was growing up in the early 1970s, it was my perception that global cooling dominated the climate narrative. My interest was further piqued by allegations of “cover-up” and “skulduggery” in 2016 in NoTricksZone and Breitbart.

Therefore, I present a review that examines the accuracy of the PCF-08 claim that 1970s global cooling consensus was a myth. This review concentrates on the results from the data in the peer-reviewed climate science literature published in the 1970s, i.e., using similar sources to those used by PCF-08.

Review of PCF-08 Cooling Myth Paper

The case for the 1970s cooling consensus being a myth relies solely on PCF-08. They state that,”…the following pervasive myth arose: there was a consensus among climate scientists of the 1970s that either global cooling or a full-fledged ice age was imminent…A review of the climate science literature from 1965 to 1979 shows this myth to be false. The myth’s basis lies in a selective misreading of the texts both by some members of the media at the time and by some observers today. In fact, emphasis on greenhouse warming dominated the scientific literature even then.” [Emphasis added].

PCF-08 reached their conclusion by conducting a literature review of the electronic archives of the American Meteorological Society, Nature and the scholarly journal archive Journal Storage (JSTOR). The search period was from 1965 to 1979 and the search terms used were “global warming”, “global cooling” and a variety of “other less directly relevant” search terms. Additionally, PCF-08 evaluated references mentioned in the searched papers and references mentioned in various history-of-science documents.

In total, PCF-08 reviewed 71 papers and their survey found 7 coolingpapers, 20 neutral papers and 44 warming papers. Their results are shown in their Figure 1.

A cursory examination of Figure 1 indicates that there is a 62% warming consensus if we use all the data and this consensus increases to 86% pro-warming, if we were to ignore the neutral papers (as was done in the 97% consensus). Therefore, the Figure 1 data seems to prove the contention in PCF-08 that 1970s global cooling was a myth.

However, I find it difficult to believe that the 1970s media “selectively misread” the scientific consensus of the day and promoted a non-existent cooling scare. Therefore, I present an alternative to the PCF-08 analysis below.

Methodology of this Review

In this review, I use an identical methodology to PCF-08, i.e., I examine peer-reviewed scientific journals. Non-peer-reviewed newspaper and magazine articles are not used. A significantly larger number of papers are presented in the current review than were used in PCF-08.

The PCF-08 database of articles is used but this is extended to examine more literature. Note that examining all of the scientific literature would have been beyond my resources. However, my literature survey was facilitated by the work of Kenneth Richard in 2016 (hereinafter, KR-16) at NoTricksZone, in which he has assembled a large database of sceptical peer-reviewed literature.

Some people may wish to ignore the KR-16 database as being from a so-called “climate denier” blog. However, almost all of the papers in KR-16 are from peer-reviewed literature and consequently it is a valid database. It is also worth noting that 16 of the papers used in the KR-16 database are also contained in the PCF-08 database.

The combined PCF-08 and KR-16 databases form the benchmark database for the current review. It was intended to significantly extend the benchmark database but, on searching the relevant journals, only 2 additional papers were found and these were added to form the database for this review.

It should be noted that KR-16 states that there were over 285 cooling papers. However, many of these papers were deleted from the current review as not being relevant. For example, several papers were either outside the 1965-1979 reference period or they emphasise the minor role of CO2 but do not consider climate trends.

I agree with PCF-08 that no literature search can be 100% complete. I also agree that a literature search offers a reasonable test of the hypothesis that there was a scientific consensus in the 1970s. I reiterate that the resulting database used in this review is significantly larger than that used by PCF-08 and consequently it should offer a more accurate test of the scientific consensus in the 1970s.

Most of the papers in the review database acknowledge the global cooling from the 1940s to the 1970s (typically 0.3 °C global cooling). Therefore, deciding between cooling, neutral or warming was relatively straightforward in most cases; namely did the paper expect the climate regime during the 1940s-1960s period to either to continue from the date that the paper was published, or did it expect a different climate regime in the medium-to-long-term?

Notwithstanding the straightforward test described above, some of the papers make contradictory statements and are thus more difficult to classify. Consequently, their classification can include an element of subjectivity. Fortunately, there are very few papers in this category and consequently an inappropriate classification does not materially affect the overall results.

The test criteria are summarised in Table 1.

ClassificationTest of Classification of PapersTypical Examples from Papers
CoolingCooling expected to either continue or initiateKukla & Kukla (1972) “…the prognosis is for a long-lasting global cooling more severe than any experienced hitherto by civilized mankind.”
NeutralEither non-committal on future climate change or expects warming or cooling to be equally possibleSellers (1969) “The major conclusions that removing the arctic ice cap would have less effect on climate than previously suggested, that a decrease of the solar constant by 2-5% would be sufficient, to initiate another ice age, and that man’s increasing industrial activities may eventually lead to the elimination of the ice caps and to a climate about 14C warmer than today…”
WarmingWarming expected to either continue or initiateManabe & Weatherald (1967) “According to our estimate, a doubling of the CO, content in the atmosphere has the effect of raising the temperature of the atmosphere (whose relative humidity is fixed) by about 2C.”
Table 1: Summary of Classification System for Papers

The search terms “global cooling” and “global warming” used by PCF-08 are used in this review but they have been expanded to include “cool”, “warm”, “aerosol” and “ice-age” because these, more general terms, return a larger number of relevant papers. Additional search terms such as “deterioration”, “detrimental” and “severe” have also been included. These would fit into the PCF-08 category of “other less directly relevant” search terms. 

Several of the papers in the database are concerned about the effects of aerosol cooling and they state that this effect dominates the effect of the newly emerging CO2-warming science. Indeed, a few papers warn of CO2cooling.

However, PCF-08 do not include any papers that refer to aerosol cooling by a future fleet of supersonic aircraft (SST’s) but several papers in the 1970s assumed an SST fleet of 500 aircraft. This seems incongruous now but, to show that this number of aircraft is not unrealistic; Emirates Airlines currently have a fleet of 244 (non-supersonic) aircraft and 262 more on order. Therefore, I have included papers that refer to the effects of aerosols from supersonic aircraft and other human activities. Of course, supersonic travel was killed-off by the mid-1970s oil crisis.

Furthermore, a number of PCF-08 and KR-16 papers were re-classified (from cooling, neutral or warming) as summarised Table 2.

Sellers (1969)WarmingNeutral
Benton (1970)WarmingNeutral
Rasool and Schneider (1972)NeutralCooling
Machta (1972)WarmingNeutral
FCSTICAS (1974)WarmingCooling
National Academy of Sciences (1975)NeutralCooling
Thompson, 1975WarmingNeutral
Shaw (1976)NeutralCooling
Bryson and Dittberner (1977)NeutralCooling
Barrett, 1978NeutralCooling
Ohring and Adler (1978)WarmingNeutral
Stuiver (1978)WarmingNeutral
Sagan et al. (1979)NeutralCooling
Choudhury and Kukla, 1979NeutralCooling
a. Amended Classifications to PCF-08 
Budyko, 1969CoolingWarming
Benton (1970)CoolingNeutral
Mitchell, 1970CoolingNeutral
Mitchell (1971)CoolingWarming
Richmond, 1972CoolingNeutral
Denton and Karlén, 1973CoolingWarming
Schneider and Dickinson, 1974CoolingNeutral
Moran, 1974CoolingNeutral
Ellsaesser, 1975CoolingNeutral
Thompson, 1975CoolingNeutral
Gates, 1976CoolingNeutral
Zirin et al., 1976CoolingNeutral
Bach, 1976CoolingWarming
Norwine, 1977CoolingWarming
Paterson, 1977CoolingNeutral
Schneider, 1978CoolingWarming
b. Amended Classifications to KR-16 
Table 2: Amendments to Classification of Papers in Database

Two examples of the amendments to the classification of the papers in the database are explained below:

  1. The Benton (1970) paper is classified as “Cooling” in KR-16 but the paper states that, “In the period from 1880 to 1940, the mean temperature of the earth increased about 0.60C; from 1940 to 1970, it decreased by 0.3-0.4°C…The present rate of increase of 0.7 ppm per year [of CO2] would therefore (if extrapolated to 2000 A.D.) result in a warming of about 0.60C – a very substantial change…The drop in the earth’s temperature since 1940 has been paralleled by a substantial increase in natural volcanism. The effect of such volcanic activity is probably greater than the effect of manmade pollutants… it is essential that scientists understand thoroughly the dynamics of climate.” [Emphasis added]. Consequently, this paper is re-classified as neutral in this review. Not the “Cooling” classification in KR-16 and not the “Warming” the classification in PCF-08).
  2. The Sagan et al. (1979)  paper is classified as “Neutral” in PCF-08 but the paper states that, “Observations show that since 1940 the global mean temperature has declined by -0.2 K…Extrapolation of present rates of change of land use suggests a further decline of -1 K in the global temperature by the end of the next century, at least partially compensating for the increase in global temperature through the carbon dioxide greenhouse effect, anticipated from the continued burning of fossil fuels.” [Emphasis added]. Therefore, this paper is re-classified as cooling in this review (conforming to the KR-16 classification).

Results from Review & Discussion

The review database contains a total 190 relevant papers, which is 2.7 times the size of the PCF-08 database. Of the 190 papers in the review database, 162 full papers/books and 25 abstracts were reviewed (abstracts were used when the full papers were either pay-walled or could not be sourced). Furthermore, 4 warming papers from PCF-08 were not reviewed because they could not be sourced. Therefore, the PCF-08 classification was used for these papers in this review.

The results from the review are summarised in Figure 2.

It is evident from Figure 2 that, for the 1965-1979 reference period used by PCF-08, the number of cooling papers significantly outnumbers the number of warming papers. It is also apparent that there are two distinct sub-periods contained within the reference period, namely:

  1. The 1968-1976 period when the 65 cooling papers greatly outnumber the 22 warming papers (74% to 26%), if we ignore the neutral papers (as was done in the Cook et al (2013). The 74% to 26% majority is an overwhelming cooling consensus.  Additionally, this is probably the period when the 1970s “global cooling consensus” originated because cooling was clearly an established scientific consensus – not the myth that PCF-08 contend.
  2. The 1977-1979 period when warming papers slightly outnumber the cooling papers (52% to 48%) – a warming majority but not a consensus.

The following observations are also worth noting from Figure 2 for the 1965-1979 reference period:

  1. Of the 190 papers in the database, the respective number of papers are 86 cooling, 58 neutral and 46 warming. In percentage terms, this equates to 45% cooling papers, 31% neutral papers and 24% warming papers, if we use all of the data.
  2. The cooling consensus increases to 65% compared with 35% warming – a considerable cooling consensus, if we ignore the neutral papers (as was done in the Cook et al (2013).
  3. The total number of cooling papers is always greater than or equal to the number of warming papers throughout the entire reference period.

Although not presented in Figure 2, it is worth noting that 30 papers refer to the possibility of a New Ice-Age or the return to the “Little Ace-Age” (although they sometimes they used the term “Climate Catastrophic Cooling”). Timescales for the New Ice Age vary from a few decades, through a century or two, to several millennia. The 30 “New Ice Age” papers are not insignificant when compared with the 46 warming papers.


A review of the climate science literature of the 1965-1979 period is presented and it is shown that there was an overwhelming scientific consensus for climate cooling (typically, 65% for the whole period) but greatly outnumbering the warming papers by 3-to-1 during the 1968-1976 period, when there were 63 cooling papers (74%) compared with 22 warming (26%).

It is evident that the conclusion of the PCF-08 paper, The Myth of the 1970s Global Cooling Scientific Consensus, is incorrect. The current review shows the opposite conclusion to be more accurate. Namely, the 1970s global cooling consensus was not a myth – the overwhelming scientific consensus was for climate cooling.

It appears that the PCF-08 authors have committed the transgression of which they accuse others; namely, “selectively misreading the texts” of the climate science literature from 1965 to 1979. The PCF-08 authors appear to have done this by neglecting the large number of peer-reviewed papers that were pro-cooling.

I find it very surprising that PCF-08 only uncovered 7 cooling papers and did not uncover the 86 cooling papers in major scientific journals, such as, Journal of American Meteorological Society, Nature, Science, Quaternary Research and similar scientific papers that they reviewed. For example, PCF-08 only found 1 paper in Quaternary Research, namely the warming paper by Mitchell (1976), however, this review found 19 additional papers in that journal, comprising 15 cooling, 3 neutral and 1 warming.

I can only suggest that the authors of PCF-08 concentrated on finding warming papers instead of conducting the impartial “rigorous literature review” that they profess.

If the current climate science debate were more neutral, the PCF-08 paper would either be withdrawn or subjected to a detailed corrigendum to correct its obvious inaccuracies.


I reiterate that no literature survey can be 100% complete. Therefore, if you uncover additional references then please send them to me in the comments. It would make this review much better if we could significantly increase the number of relevant references.

Additionally, if you disagree with the classification of some of the references then please let me know why you disagree and I will consider appropriate amendments. Your comments on classification would certainly increase the veracity of the review by providing an independent assessment of my classifications.


The references used in this review and their classification are included in the spreadsheet here:

References-Global Cooling Consensus.xlsx

Revision 02

29-Dec-2022: Minor errors corrected by Angus McFarlane.

Continue reading

Hansen 1988 Revisited

Hansen’s 1988 temperature projections have recently received quite a bit of attention, e.g., RealClimate, WUWT and SkS. The pro-AGW sites state than Hansen has done very well, whereas the anti-AGW say that he hasn’t. Therefore, I thought that it would be a good time to revisit Hansen’s work to determine how well he did?

Temperature Sensitivity & What Can We Learn?

Dana1981 @ SkS states that:

“The observed temperature change has been closest to Scenario C, but actual emissions have been closer to Scenario B. This tells us that Hansen’s model was “wrong” in that it was too sensitive to greenhouse gas changes. However, it was not wrong by 150%, as Solheim claims. Compared to the actual radiative forcing change, Hansen’s model over-projected the 1984-2011 surface warming by about 40%, meaning its sensitivity (4.2°C for doubled CO2) was about 40% too high.

What this tells us is that real-world climate sensitivity is right around 3°C, which is also what all the other scientific evidence tells us. Of course, this is not a conclusion that climate denialists are willing to accept, or even allow for discussion.”

Perhaps. Climate sensitivity may be ≈ 3°C but we can also learn several other things as discussed below.

How Well Did Hansen Do?

Hansen Compared With the Real World

Figure 1 shows Hansen’s scenarios compared with the GISS Land-Ocean Index (LOTI). I have also added Dana1981’s data as Scenario D. This is the Scenario B data but with the temperature sensitivity reduced from 4.2°C to 2.7 °C. Dana did this by multiplying the Scenario B data by a factor of (0.9*3/4.2), which equates to temperature sensitivity of 2.7 °C (see SkS for the data). The SkS estimate for Scenario D appears to be based on Schmidt (2009).

Figure 1: Hansen’s 1988 Scenarios compared with Real-world Temperatures

It is evident from Figure 1 that the best fit for real world temperatures is Scenario C. However, the pro-AGW in SkS state that Scenario C is irrelevant because it uses the “wrong” sensitivity of 4.2°C and incorrect emissions. Therefore, perhaps I should modify my conclusion to real-world temperatures are following Scenario D, which has the “right” temperature sensitivity of 2.7°C and emissions that are close to actual emissions. It makes no difference; Scenarios C and D are similar, although Scenario D has tended to under-predict temperatures for the last 30 years or so.

2012 Projections

Hansen’s temperature projections for 2012 are compared with the LOTI data in Table 1. It should be noted that the 2012 LOTI temperature estimate is based on the 12-month running average from Jun-2011 to May 2012.


2012 Anomaly (°C)








Hansen (1988a)




Hansen (1988a)




Hansen (1988a)




Dana (2011)





Note: The comparison with LOTI is based on Scenario/LOTI.

Table 1: Comparison of Hansen’s 1988 Temperature Projections for 2012

Comparing Hansen’s temperature projections with LOTI, it is evident that Hansen’ didn’t do very well.

Scenarios A and B overestimated real-world temperatures by a whopping 126% and 105% respectively. Scenario D over-predicts by 28% and even the no-increase-in-emissions Scenario C over-predicts real-world temperatures by 16%.

What do we learn? We could argue that climate sensitivity should be reduced to ≈ 2.1°C to correspond to the 28% over-prediction in Scenario D. However, I would suggest that we wait a few more years to determine the trend more accurately.

2019 Projections

The timeline for Hansen’s temperature projections for 2019 is presented in Table2. A summary of the comments made by different commentators are included to show how the favoured scenario/projection evolved with time.


2019 Anomaly (°C)



Scenario D (%)





Hansen (1988a)

In May 1988, Hansen states in AGU paper that, “Scenario A, assumes that growth rates of trace gas emissions typical of the 1970s and 1980s will continue indefinitely…[but]…since it is exponential, must eventually be on the high side of reality in view of finite resource constraints…Scenario B is perhaps the most plausible of the three cases.”



Hansen (1988b)

In June 1988, Hansen states to US Congressional Committee that Scenario A was “business as usual.”



Hansen (2005)

Hansen states that, “In my testimony in 1988, and in an attached scientific paper… Scenario A was described as “on the high side of reality”…The intermediate Scenario B was described as “the most plausible”… is so far turning out to be almost dead on the money.”



Hansen (2006)

Hansen assesses the predictions and states that the close agreement, “for the most realistic climate forcing (scenario B) is accidental.” He states current estimate for sensitivity is 3 ± 1°C.



Schmidt (2007)

RealClimate blog, Schmidt states that forcings in Scenario B are “around 10% overestimate.”



Schmidt (2009)

RealClimate blog, Schmidt states that Scenario B, “is running a little high compared with the actual forcings growth (by about 10%)”



Schmidt (2011)

RealClimate blog by Schmidt, “As stated last year, the Scenario B in that paper is running a little high compared with the actual forcings growth (by about 10%)”



Dana (2011)

Skeptical Science blog, climate sensitivity reduced from 4.2 to 2.7°C for Scenario B. Use this as the benchmark for comparison.



Schmidt (2012)

RealClimate blog, Schmidt states that Scenario B, “is running warm compared to the real world (exactly how much warmer is unclear)”



Hansen (1988a))

Hansen’s original Scenario C. This is the commitment scenario with emissions held at year 2000 levels. Include this as a measure of how well the other scenarios perform.

Note: The comparison with Scenario D is based on Scenario/Scenario D

Table 2: Evolution of Hansen’s 1988 Temperature Projections for 2019

It is evident from the timeline and narrative in Table 2 that the evolution in temperature is generally downwards; apart from the brief upwards spurt for US Congressional Committee presentation in June 1988 (more on this in unethical conduct later in this blog).

The following points are also evident:

  • There is a large reduction in the estimate for the 2019 temperature anomaly from Hansen’s estimate of 1.57°C in 1988 (as presented to the US Congress) to Dana’s estimate of 0.69°C in 2011.
  • Until recently (Schmidt, 2012) the overestimate in Scenario B was portrayed as ≈ 10% but Dana at SkS (2011) showed that the overestimate was ≈ 44%.

What do we learn? All of the pro-AGW blogs states that the Hansen Scenario B was pretty good estimate. I suggest that an error of ≈ 44% is pretty bad.

Unethical Behaviour

Hansen’s paper Hansen (1988a) was published in August 1988 but it is important to note that it was accepted for publication on 6 May 1988. This date is particularly relevant because Hansen stated on 6 May 1988 that:

Yet, one month later Hansen (1988b)
in his congressional testimony here he described Scenario A as “business as usual” (see below):

Notice that Scenario A is stressed to be “business as usual”. No mention to Congress that Scenario B was “most plausible” and that Scenario A was “on the high side of reality”.

Later (2006), Hansen re-worded his 1988 congressional testimony to be Scenario A, “was described as on the high side of reality”.

From the foregoing, it is evident that Hansen did not describe to Congress in 1988 that Scenario A was on the “high side of reality”. At best, he has been economical with the truth by re-writing history and (at worst) he has been unethical and totally unprofessional.


I offer the following conclusions regarding Hansen 1988:

  • Temperature forecasts (sorry, should I use the politically correct term projections?) for 2019 have plummeted from 1.57°C in 1988 to 0.69°C in 2011.
  • Estimates of temperature are in error by ≈ 60 for Scenario B and 127% for Scenario A.
  • Climate sensitivity has also fallen from ≈ 4.2°C to ≈ 2.1-2.7°C, i.e., it has fallen to 50-64% of Hansen’s 1988 estimates.

These sorts of errors do not represent pretty good estimates.

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.


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.


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


  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.