Monthly Archives: April 2012

The Misrepresentation Of Climate Science

The Boulder Daily Camera had an article on April 20 2012 that illustrates the convoluted ways individuals seek to fit real world observations into the IPCC worldview. The article is By Breanna Draxler

On Niwot Ridge west of Boulder, contrasting climates 5 miles apart Scientists find warming at 10,000 feet, cooling at 12,700 feet

It reads [with highlighting and my comments]:

Scientists doing climate research on Niwot Ridge in the mountain’s west of Boulder found a surprising trend: At 10,000 feet of elevation, conditions have become warmer and drier over the past few decades, but at 12,700 feet, conditions are actually cooler and wetter.

“We know the western U.S. has been warming. It’s concentrated in the spring at the forest site. But we see just the opposite at the high elevation site above the tree line,” said Mark Williams, the study’s principal investigator.

My Comment:   The high elevation data actually shows a cooling and the forest site is only warming in the spring. This should be a red flag that there is more going on than a western U.S. warming, or even if this warming is actually occurring at higher elevation sites. Indeed, even lower elevation sites are suspect; e.g. see

Uncertainty in Utah Hydrologic Data: Part 1 On The Snow Data Set by Randall P. Julander

Uncertainty in Utah Hydrologic Data: Part 2 On Streamflow Data by Randall P. Julander

Uncertainty in Utah: Part 3 on The Hydrologic Model Data Set by Randall P. Julander

Williams said snowfall at the higher station has doubled in the last 60 years — the period for which scientists have been collecting precipitation and temperature data at Niwot Ridge. Temperatures, too, have dropped significantly during the winter months, from November through March.

The scientists attribute the cooling to a small-scale climatic balancing act. The warmer temperatures at lower elevations cause snow to evaporate. This moisture in the air is then drawn upward and to the west. When it reaches the continental divide, the moisture falls as snow.

My Comment:  First, the amount of water vapor from lower elevation evaporation in the wintertime would be a very small contribution to the precipitation at higher elevation. This snowfall occurs at Niwot Ridge, and elsewhere in the Rockies, as Pacific moisture is advected eastward over the western U.S. Indeed, higher snowfall indicates a storm track that has resulted in a higher frequency of winter storms.  This also would explain the lower temperatures from November to March. In the 2011-2012 season, snowfall was  quite a bit less since the storm track was far to the north. In the 2010-2011 season the storm track was persistently further south and large amounts of snow fell.

The additional snowfall boosts the albedo effect, which reflects sunlight back into the atmosphere and causes the localized cooling. The higher station is above treeline, so the white snow reflects more sunlight than the tree-covered location of the lower station.

My Comment: There is snow on the ground at Niwot in the winter! Moreover, the albedo effect is a trivial effect at Niwot Ridge in comparison to the advection of cold air at this level of the atmosphere. Indeed, Niwot Ridge is an excellent location to obtain regionally representative long-term temperature trend measurements, as the frequent strong airflow permits a sampling of the larger scale atmosphere.

The findings are particularly surprising since the two research stations are only five miles apart, said Williams, who is a fellow at the Institute of Arctic and Alpine Research and a geography professor at the University of Colorado.

The localized cooling happens amidst a larger warming trend in the West.

My Comment: A scientifically robust approach would be to also look at whether the warming the forested site is due to local effects. In addition, the lower tropospheric temperature anomalies for the same time period and geographic location should be compared to these surface sites.

Bill Bowman is director of mountain research station, which runs the climate program. He has been working on Niwot Ridge for decades and said the warming picked up steam in the 1990s due to human-emitted greenhouse gases.

“Across the western U.S. there is a very clear trend in warming, and in earlier snowmelt, and in greater loss of water due to evaporation at the surface,” Bowman said. “The trend will continue almost certainly because humans are continuing to emit greenhouse gases unabated.”

As a result of these emissions, Williams suspects that the cool temperatures and increased snowfall are only temporary.

“My guess is we put enough energy in the atmosphere, the warming trend will move up above the treeline,” Williams said.

Niwot Ridge is the highest of the 26 long-term ecological research sites around the world. The site 25 miles west of Boulder is thousands of acres in size and includes a range of ecosystems, such as subalpine forest, tundra, talus slopes, glacial lakes and wetlands. Continued warming could wreak havoc on these natural systems and the local communities by increasing the risk of wildfires, reducing municipal water supplies, or triggering another mountain pine beetle outbreak.

“Climate is changing and we end up with climate weirding — unpredictable climate extremes,” Williams said.

My Comment: Here is the pervasive assumption that changes in climate statistics are due to the emissions of greenhouse gases. This is the  IPCC viewpoint that is being repeated (along with the new catch phrase “climate weirding“).  Williams’s statement that he is guessing places the confidence in the statements in the article in their proper place.

He used two recent examples to demonstrate the volatility of current climatic conditions and the unpredictability of future conditions. Last year was the latest recorded date for snowmelt at the research site, and this year was the earliest on record, he said. The difference between the two was 3.5 months.

“You normally don’t see that big of a difference on back-to-back years,” Williams said.

Likewise, on a shorter time-scale, this February was the snowiest on record, while March was the driest.

My Comment:  These large excursions in climate are actually quite typical. Indeed, rather than cherry picking that cooling is local and warming is global, such studies should recognize the overwhelming dominance of regional atmospheric/ocean circulations in causing these anomalies.

“It’s beyond what we can predict in terms of climate change at this point,” Williams said.

The study was published in one of a series of six articles in the April issue of BioScience.

My CommentThis first sentence is finally a correct statement. However, Williams and Bowman should have recognized this also applies to the claims that attribution of these anomalies is also not well understood.

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Comments On The Paper “Skillful Predictions Of Decadal Trends In Global Mean Surface Temperature” By Fyfe Et Al 2012

Jos de Laat of KNMI altered us to the paper

Fyfe, J. C., W. J. Merryfield, V. Kharin, G. J. Boer, W.-S. Lee, and K. von Salzen (2011),Skillful predictions of decadal trends in global mean surface temperatureGeophys. Res. Lett.,38, L22801, doi:10.1029/2011GL049508

which is an example of the overstatment of model predictive skill.

The abstract reads

We compare observed decadal trends in global mean surface temperature with those predicted using a modelling system that encompasses observed initial condition information, externally forced response (due to anthropogenic greenhouse gases and aerosol precursors), and internally generated variability. We consider retrospective decadal forecasts for nine cases, initiated at five year intervals, with the first beginning in 1961 and the last in 2001. Forecast ensembles of size thirty are generated from differing but similar initial conditions. We concentrate on the trends that remain after removing the following natural signals in observations and hindcasts: dynamically induced atmospheric variability, El Niño-Southern Oscillation (ENSO), and the effects of explosive volcanic eruptions. We show that ensemble mean errors in the decadal trend hindcasts are smaller than in a parallel set of uninitialized free running climate simulations. The ENSO signal, which is skillfully predicted out to a year or so, has little impact on our decadal trend predictions, and our modelling system possesses skill, independent of ENSO, in predicting decadal trends in global mean surface temperature.

There are key admissions in the article which should clearly alert a reader to be skeptical about this observational/model comparison. A most revealing comment is that [highlight added]

Since observation-based and model-based climates tend to differ, hindcasts which are initialized to be near the observations tend to drift towards the model climate. For short term hindcasts this is accounted for by removing the mean bias. However, for longer term decadal hindcasts a linear trend correction may be required if the model does not reproduce long-term trends. For this reason, we correct for systematic long-term trend biases following a procedure detailed in the auxiliary material. We process the three sets of hindcasts using the different initialization techniques separately, but combine the predicted anomalies into one thirty-member ensemble in the following analysis. The ten-member ensemble of freecasts are also trend corrected in this way.

The authors define “freecasts” as

These are climate simulations (referred to here as “freecasts”) which evolve freely based on the specified external forcing.

This is quite an amazing admission. They write that the  “model does not reproduce long-term trends” than “a linear trend correction may be required” and “we correct for systematic long-term trend biases.” The  model results are tuned. They are not freecasts“.

The authors also fail to compare their results with other temperature data sets such as the lower tropospheric temperature anomalies and trends. As we show in our papers

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr.,  J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the  surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841.

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr.,  J.R. Christy, and R.T. McNider, 2010: Correction to: “An alternative explanation for differential temperature trends at the  surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841″, J. Geophys. Res.,  115, D1, doi:10.1029/2009JD013655.

there is a warm bias in the surface temperature data. The authors chose to ignore this finding in their study. Instead they tuned their model results to the observed temperature data.

As an editor, at a minimum I would have insisted on this comparison before this paper would have been accepted. As written, however, the Fyfe et al article adds no robust evidence that the models have skill at predicting temperature changes over decadal and longer time periods. Indeed, they provide further evidence of the lack of skill of the multi-decadal climate model predictions.

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An Example Of The Misstatement of Fact On Climate Change

Alvin Stone of the ARC Centre of Excellence for Climate System Science at the University of New South Wales [h/t to Marc Hendrickx] made the following comment [highlight added] in the discussion at The Conversation in the post

If you want to roll the climate dice, you should know the odds

Okay, let’s talk spin then. It is very well established that the great majority of climate scientists (in the 90% band up or down a couple of notches depending on the survey) agree that climate change is occurring and that anthropogenic carbon dioxide is the main culprit.

Many were working in this field before it was fashionable and have pretty much been of this understanding for a few decades.

Now, a tiny minority doubt this case but none has published a single paper that undermines the fundamental science.

So, your arguments suggest that you are right and that 95-97% of climate scientists are either knowingly misrepresenting their position for whatever reason are too stupid to understand the real science.

So, how would you classify the climate scientists who support anthropogenic emissions hypothesis. In your eyes are they liars, easily misled or just plain stupid?

This statement by Mr. Stone is not an isolated example, unfortunately, but is a view that is erroneously communicated. This is why I and a group of Fellows of the American Geophysical Union published the following article

Pielke Sr., R., K.  Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D.  Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E.  Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J.  Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases.   Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American   Geophysical Union.

Or for an even wider demonstration that the comment by Mr. Stone misrepresents the actual understanding of the science, see

National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties.             Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington,D.C., 208 pp

where it is written

“…..the traditional global mean TOA radiative forcing concept has some important limitations, which have come increasingly to light over the past decade. The concept is inadequate for some forcing agents, such as absorbing aerosols and land-use changes, that may have regional climate impacts much greater than would be predicted from TOA radiative forcing. Also, it diagnoses only one measure of climate change—global mean surface temperature response—while offering little information on regional climate change or precipitation. These limitations can be addressed by expanding the radiative forcing concept and through the introduction of additional forcing metrics. In particular, the concept needs to be extended to account for (1) the vertical structure of radiative forcing, (2) regional variability in radiative forcing, and (3) nonradiative forcing.”

Anthropogenic carbon dioxide is NOT the main [dominant] culprit affecting changes in climate.  It is just one of a diverse set of human and natural climate forcings.

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Comment On Ocean Heat Content “World Ocean Heat Content And Thermosteric Sea Level Change (0-2000), 1955-2010″ By Levitus Et Al 2012

I was alerted by March Morano and others today to a new paper on changes in upper ocean heat content between 1955 and 2010. The new paper is

Levitus, S., et al. (2012), World ocean heat content and thermosteric sea level change (0-2000), 1955-2010, Geophys. Res. Lett.,doi:10.1029/2012GL051106, in press

with the abstract [highlight added]

We provide updated estimates of the change of heat content and the thermosteric component of sea level change of the 0-700 and 0-2000 m layers of the world ocean for 1955-2010. Our estimates are based on historical data not previously available, additional modern data, correcting for instrumental biases of bathythermograph data, and correcting or excluding some Argo float data. The heat content of the world ocean for the 0-2000 m layer increased by 24.0×1022 J corresponding to a rate of 0.39 Wm-2 (per unit area of the world ocean) and a volume mean warming of 0.09ºC. This warming rate corresponds to a rate of 0.27 Wm-2 per unit area of earth’s surface. The heat content of the world ocean for the 0-700 m layer increased by 16.7×1022 J corresponding to a rate of 0.27 Wm-2 (per unit area of the world ocean) and a volume mean warming of 0.18ºC. The world ocean accounts for approximately 90% of the warming of the earth system that has occurred since 1955. The thermosteric component of sea level trend is 0.54 mm yr-1 for the 0-2000 m layer and 0.41 mm yr-1 for the 0-700 m layer of the world ocean for 1955-2010.

They list their key points as

  • A strong positive linear trend in exists in world ocean heat content since 1955
  • One third of the observed warming occurs in the 700-2000 m layer of the ocean
  • The warming can only be explained by the increase in atmospheric GHGs

The third bullet they list is just a regurgitation of the IPCC claim that only increases in atmospheric GHGs can cause warming in the oceans.  This is a model based claim and seems to be standard for the Levitus papers. Nonetheless, the observation part of his paper is quite informative.

The value of using the ocean heat as the metric to diagnose global warming and cooling was discussed in the papers

Ellis et al. 1978: The annual variation in the global heat balance of the Earth. J. Geophys. Res., 83, 1958-1962

Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer.  Meteor. Soc., 84, 331-335.

Pielke Sr., R.A., 2008: A broader view of the  role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.

First, if 1/3 of the heating really is at depths below 700m, this works to discount the value of using the annual average global surface temperature trend as the diagnostic to monitor global warming as was discussed in the post

Torpedoing Of The Use Of The Global Average Surface Temperature Trend As The Diagnostic For Global Warming

Second,  in the Levitus et al figure, reproduced below, there is a more-or less monotonic increase of heat since about 1990.  In the surface to 2000 meter depth, this accumulation of about 14 X 1022 Joules corresponds to a rate of heating of ~ 0.41 Watts per meter squared. As they also note in their paper, about 1/3 of this heating is at levels below 700m.

There is, therefore, a question about their analysis of heating since the Argo network became dense enough to provide a more homogenous analysis of upper ocean temperatures in 2003.  NOAA’s Pacific Marine Environmental Laboratory presents the analysis below which shows a muted warming in the upper 700m since 2003 as compared with the Levitus et al data.

In any case, let’s just use the Levitus et al 2012 analysis to compare with the prediction made by Jim Hansen. In Jim’s comment in 2005,  he wrote

The Willis et al. measured heat storage of 0.62 W/m2 refers to the decadal mean for the upper 750 m of the ocean. Our simulated 1993-2003 heat storage rate was 0.6 W/m2 in the upper 750 m of the ocean. The decadal mean planetary energy imbalance, 0.75 W/m2, includes heat storage in the deeper ocean and energy used to melt ice and warm the air and land. 0.85 W/m2 is the imbalance at the end of the decade [note added: he is referring to the 1990s].

Thus either using the 1955 to 2010 time period, or the shorter time period from 1990 to 2010 in the Levitus et al 2012 paper, the diagnosed magnitudes of ocean warming and global warming are significantly less than claimed by Jim Hansen in 2005. This discrepancy is even larger if we use the NOAA’s Pacific Marine Environmental Laboratory data.

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Sea Ice Prediction – Update To 2012

Update#7 

I agree with Grant Foster and dana1981 that  it is a bad idea to make claims about short trends because the error bars in mapping to longer term trends are going to be large.  I should have presented my reasoning for doing this more clearly.

In examing the Vinnikov et al 1999 paper, I did not explain that my use of their trend values to state that short term assessments have value for quantities which involve inertia (mass) such as heat and ice. If the sea ice area were to recover to its original area and thickness (for whatever reason), for example, it does not matter what its long term trend was.  The long term trend (if there is one) would be reset. I have made this point often with respect to ocean heat content (e.g. see). It also applies to sea ice (although area is only one part of it).

Trend analysis, as being interpreted by Grant Foster and dana1981  is fundamentally an assumption that there is an overarching control on the long time period. My perpsective is to see if there are change points which interrupts that trend (e.g. 2006). I look forward to seeing what they obtain for sea ice area and for insolation-weighted sea ice using the same approach they used for sea ice extent.

Update #6  Skeptical Science has joined with Grant Foster to dismiss the claim in my posts that the Vinnikov et al 1999 model prediction overpredicted Arctic sea ice loss. Indeed, they concude the opposite. The Skeptical Science post is Lessons from Past Predictions: Vinnikov on Arctic Sea Ice. They both critizise my post in that I visually extracted the trend and also cherrypicked the start of the time period.

The visual examination of a time series to look for patterns is a classic approach that has been used in developing atmospheric boundary layer forumla for use in models, as I learned from Hans Panofsky years ago.  The selection of a starting time (2006) was based on  this figure, and it does show a clear breakpoint. David Douglass has used this concept of breakpoints (although for different years) with respect to ocean heat content in his paper

D.H. Douglass, R.S. Knox, 2012: Ocean heat content and Earth’s radiation imbalance. II. Relation to climate shifts. Physics Letters A. http://dx.doi.org/10.1016/j.physleta.2012.02.027

The Skeptical Science weblog post concluded that “the Arctic sea ice decline is about 27 years ahead of the Vinnikov model predictions.”

I did make an error in my post by assuming that anomalies in sea ice extent and sea ice area would be the same. I am convinced from the analyses by Grant Foster and dana1981 that this is incorrect. I have always focused on sea ice area since this is the more accurate way to diagnose the albedo radiative feedback.

Since, Grant Foster and dana1981 at Skeptical Science have the statistical tools ready to analyze the data, to convincingly show that Arctic sea ice decline is as advanced as they state, that they

i) perform the same analysis for sea ice area that they have done for sea ice extent

and

ii) perform the analysis of insolation-weighted sea ice trends; e.g. see

Pielke Sr., R.A., G.E. Liston, and A. Robock, 2000: Insolation-weighted  assessment of Northern Hemisphere snow-cover and sea-ice variability.  J. Geophys. Res. Lett., 27, 3061-3064

and

Pielke Sr., R.A., G.E. Liston, W.L. Chapman, and D.A. Robinson, 2004:  Actual and insolation-weighted Northern Hemisphere snow cover and sea  ice — 1974-2002. Climate Dynamics, 22, 591-595 DOI10.1007/s00382-004-0401-5.

With these two other analyses, we will see if the Arctic sea ice is actually in the “death spiral” as they report based on their analysis.  They may be correct, but from the figure below using sea ice area from the Cyrosphere Today, it certainly looks like a hiatus in its demise since 2006.

Update #5   Some of the readers of my weblog are wondering who Tamino is.  The scientific debate on the sea ice issue, of course, is independent of who makes comments, but professional courtesy requires that an individual identify themselves. Tamino is Grant Foster of Tempo Analytics in Garland,  Maine [h/t Anthony Watts]. He has a peer-reviewed publication with Stefan Rahmstorf

Grant Foster and Stefan Rahmstorf 2011: Global temperature evolution 1979–2010. Environ. Res. Lett. 6 044022 doi:10.1088/1748-9326/6/4/044022.

and one wirth Mike Mann, James Annan, and Gavin Schmidt

Foster, G., J. D. Annan, G. A. Schmidt, and M. E. Mann (2008), Comment on ‘‘Heat capacity, time constant, and sensitivity of Earth’s climate system’’ J. Geophys. Res., 113, D15102, doi:10.1029/2007JD009373.

His expertise clearly is in statistics, and he wants to apply this skill to climate analysis.

He does have a quite good study published February 12 2012 titled

Pine Beetle Infestation and Fire Risk in the Black Hills

where he writes as part of his conclusion

Surely, excessive rhetoric about the urgent fire danger posed by pine beetle infestation, sometimes to the point of hysteria, does not serve the public interest.

[he should apply the same advice to his treatment of climate science]

His real world identity, and measured scientific approach, however, conflicts with his handling of his posts and those of his commenters on Tamino.  Tamino has a number of the same disparaging commenters that appear on Skeptical Science.  The failure to identify yourself when discussing a scientific issue shows a lack of professional courtesy.

Now, with respect to the sea ice discussion,  I have asked the question of Grant Foster

What criteria in the observations would have to occur, before you would reject the model predictions of sea ice coverage?

Provide a benchmark criteria to assess for the coming seasons. From my perspective, I view that the models are not refuted if the anomalies in sea ice areal coverage fall at close to or greater than the rate of, say, the order of 10o,000 square kilometers per decade in the next few years.

Update #4  April 26 2012   In the latest comment in the Tamino post Do the Math, I am critizied for using sea ice area and not sea ice extent (along with the now to be expected personal insults by a number of commenters on Tamino).   However, in my view since it is area, not extent that better maps with radiative feedback, the Cryosphere Today presentation is preferred. Perhaps Tamino, should show the Vinnikov et al prediction (if he can obtain it) for the years up to 2012 and beyond in terms of  sea ice area.

In terms of the Vinnikov et al plot, there clearly is an ambiquity as the Hadley and the GFDL results for sea ice extent are so different. To repeat, the use of anomalies provides a way to avoid the absolute value of sea ice extent or area, as both are quite dependent on the precise definition that is used to define them (as illustrated by the Hadley and GFDL analyses).   Tamino would have to show that the anomalies for the extent and are coverage were distinctly different, and then I would agree that the two should not be interpreted as having the same anomalies.

There is one valid point, however, that is raised in the comments. Is the break-point visible in 2006 statistically significant? We are pursuing this analysis and will report on this weblog when we have results.

Finally, if Tamino wants to have a constructive discussion, I recommend he also examine the magnitude of the insolation-weighted radiative feedback from sea ice area coverage, as we presented in our papers

Pielke Sr., R.A., G.E. Liston, and A. Robock, 2000: Insolation-weighted  assessment of Northern Hemisphere snow-cover and sea-ice variability.  J. Geophys. Res. Lett., 27, 3061-3064

and

Pielke Sr., R.A., G.E. Liston, W.L. Chapman, and D.A. Robinson, 2004:  Actual and insolation-weighted Northern Hemisphere snow cover and sea  ice — 1974-2002. Climate Dynamics, 22, 591-595 DOI10.1007/s00382-004-0401-5

Of course, this discussion of a break point becomes moot if the sea ice decline prior to 2006 returns.  However, until and unless that happens, Tamino (and a number of the commenters) are not, in my view, following the scientific method which is to seek to refute hypothses (i.e. in this case the Vinnikov et al or other model preditions) rather than defending the models. Tamino asks the question

Could it be that Roger Pielke is actually aware of that, but that he really doesn’t care about portraying sea ice changes correctly, he only cares about discrediting global warming science?”

This question is absurd and insulting, but it does show Tamino’s mindset.  I am not discussing global warming science at all in the sea ice post.  I am seeking to refute (test) the Vinnikov et al prediction. That is the scientific method.  If you are convinced and present evidence, as you have, that I have been unsucessful so far, that is an appropriate scientific debate. I can then counter with other information.  However, to misrepresent my views on climate science, when I specifically referred you to a summary article on my views;

Pielke Sr., R., K.  Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D.  Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E.  Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J.  Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases.   Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American   Geophysical Union

is dishonest.

Update #3  April  25 2012 The comments on Tamino on their post Do the Math raised the issue of why I chose to use the long-term analysis of near daily of anomalies of sea ice area rather than yearly averages of sea ice extent for my comparison with the Vinnikov et al result.  The answer is that there is more information in the anomalies. For example, see

The absolute values on the left side of the Vinnikov et al plots are also misleading, as clearly the real world annual average of sea ice extent shown in the above figure from The Cryosphere Today is not even close to the values plotted for the GFDL model or what are reported in their paper to be the Chapman and Walsh, or Parkinson et al observed data.  The reason for the disagreement is likely due to different definitions of sea ice extent. Showing anomalies from the current data on The Cryosphere Today is a way to focus just on the anomalies and their trend over time, and to avoid dealing with the absolute values themselves.

The comments on Tamino disparage the use of visual information to interpret the behavior of the sea ice.  Instead they focus on linear (or near-linear trend) quantitative analyses. However, if the system is not behaving in a near linear (monotonic) way (such as shown in the Levitus et al figure 1 right), their analysis will miss obvious changes in the behavior of the data.  Everyone, if they are being objective, will see a break in the slope of the anomaly plots since 2006.

Finally, reading the comments on Tamino illustrates the lack of professional courtesy that is the benchmark of science.  I am not presenting my comments on Tamino for that reason.  Most of the commenters also hide behind anonymity to insult rather than actually debate a scientific issue. The Tamino weblog approach illustrates the unfortunate state of scientific debate with respect to climate state. They are defending the model predictions, rather than follow the scientific method to determine if there are real world observstions that refute the models (which are, afterall, hypotheses). If all attempts fail to reject the model predictions, than it is accepted as a robust prediction and attribution tool. A simple question to Tamino would be what criteria in the observations would have to occur, before he would reject the model predictions of sea ice coverage?

Update #2 April 24 2012  There is a comment by “Ned” at Tamino that presents the plot of “annual mean sea ice extent” and show that it has decreased faster than the Vinnikov et al model results.  I disagree that this is the proper metric to show, and that anomalies provide the more appropriate comparison as this avoids the confusion as to which value is actually plotted in the Vinnikov et al paper with respect to the models.  Moreover, the plot of anomalies shows why using linear (or quasi-linear trends) is misleading. The sea ice data had a significant change in its trend in 2006. Tamino and his commenters appear unable or uninterested in actually constructively discussing this issue. They have also chosen to ignore the inconvenient behavior of the Antarctic sea ice coverage.

Update April 24 2012 – Tamino has a post titled

Do the Math

where he disagrees with my post. Unfortunately, he does not present an honest view of what I wrote. He writes

I refer the reader to our advice on “Defense Against the Dark Arts.” His misdirection is revealed by Step 3: look at more than they show you, and be especially wary of time spans that are too brief and areas that are too small.  In this case the “time spans that are too short” alarm is flashing red — not only has Pielke cherry-picked his starting point, he’s comparing a predicted long-term trend to an observed time span of far less than a decade.  That’s foolish of him, and misleading to his readers.

Tamino also writes

Note also that when you start “since 2006″ or later, the error bars on the estimated rates are rather large.  The trend for such short time spans is so uncertain, it really doesn’t give much information.

In other words, Tamino, for some reason claims “error bars” are too large which is absurd, as the sea ice coverage data analysis is quite robust, and 2006 was chosen as it is clearly a break-point in the sea ice data.

He estimates the trend not just from 2006 to the present, but from every starting year since 1999 to the present and has, for example, the claim that the trend from 2009 to the present is -2 million km squared per decade. This is obviously quite different from what is shown below from The Cryosphere Today below. Perhaps Tamino should take his own advice and “do the math“.

He then concludes with a motive

Could it be that Roger Pielke is actually aware of that, but that he really doesn’t care about portraying sea ice changes correctly, he only cares about discrediting global warming science

Tamino is quite disingenuous in his post.  I do not disagree that the Arctic sea ice has been decreasing. My post was to compare the sea ice anomaly trends that were presented in the Vinnikov et al paper to real world observations updated to 2012. The figure in the Vinnikov et al 1999 paper shows a rather monotonic (but increasing over time) decrease  in Arctic sea ice content with time.  Tamino ignores what is obvious in even a visual comparison between the Vinnikov et al plot and the real world observations that the decline has stopped, at least for now.

As to motive, I did not even discuss global warming in the post. His ad hominem end statement that I only care about “discrediting global warming science” is an example of him seeking to discredit anyone who introduces a counter viewpoint. If Tamino was actually honest in his post, he would present the same type of figure from the models as done by Vinnikov et al 1999.  In addition, he would report honestly on my view on climate science and global warming which we summarized in our paper

Pielke Sr., R., K.  Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D.  Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E.  Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J.  Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases.   Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American   Geophysical Union.

**********original post******************

In 2009 I posted the following

A Comment On A 1999 Paper “Global Warming And Northern Hemisphere Sea Ice Extent By Vinnikov Et Al

I have edited the post below using crossouts and underlining, to show that the models are even more out of sync that they were in 2009. There are also very recent discussions on the Arctic sea ice anomalies at WUWT and Real Climate.

Ten  Thirteen years ago, the following paper was published.

Vinnikov et al., 1999: Global warming and northern hemisphere sea ice extent. Science. 286, 1934-1937.

In this paper, there is a presentation of the model predictions of sea ice extent along with observations up to 1998.  This weblog introduces the subject of how well have the model predictions done.

Their abstract includes the statement (referring to the GFDL and Hadley global climate models)

“Both models used here project continued decreases in sea ice thickness and extent throughout the next century.”

In the conclusion to their paper, they write

“Both climate models realistically reproduce the observed annual trends in NH sea ice extent. This suggests that these models can be used with some confidence to predict future changes in sea ice extent in response to increasing greenhouse gases in the atmosphere. Both models predict continued substantial sea ice extent and thickness decreases in the next century.”

In their paper (in Table 1) they have model predictions (in units of linear trend in 106 square kilometers per decade) listed for the GFDL climate model from 1978-1998 of -0.34 (and -0.19 using a “smoothed model output“) and for the Hadley Centre climate model -0.18 (and -0.16 using a “smoothed model output“).

A value of -0.18 is the loss of sea ice area of 180000 square kilometers per decade, for example.

The first figure below is from the Vinnikov et al 1999 paper  with respect to the model predictions, while the second and third figures are the sea ice areal converage for the Northern Hemisphere up to the present (April 20 2012)  and the Antarctic sea ice areal anomaly from The Cryosphere Today.

Until later in 2007, the sea ice areal extent continued to decrease in a manner which, at least visually, is consistent with the Vinnikov et al 1999 predictions (although the actual values of areal coverage differ substantially between the observations and the predictions, perhaps as a result of their formulation to compute areal coverage).

However, since 2006, the reduction has stopped and even reversed. Perhaps this is a short term event and the reduction of sea ice extent will resume. Nonetheless, the reason for the turn around, even if short term, as well as the long term increase in Antarctic sea ice coverage, needs an explanation.  Moreover, this data provides a valuable climate metric to assess whether the multi-decadal global models do have predictive skill as concluded in the Vinnikov et al 2009 paper.

It has been claimed that most of the recent sea ice is thin and thus will melt quickly this spring. Perhaps so. However, in terms of the albedo feedback into the atmosphere that we discuss in our papers

Pielke Sr., R.A., G.E. Liston, and A. Robock, 2000: Insolation-weighted  assessment of Northern Hemisphere snow-cover and sea-ice variability.  J. Geophys. Res. Lett., 27, 3061-3064

and

Pielke Sr., R.A., G.E. Liston, W.L. Chapman, and D.A. Robinson, 2004:  Actual and insolation-weighted Northern Hemisphere snow cover and sea  ice — 1974-2002. Climate Dynamics, 22, 591-595 DOI10.1007/s00382-004-0401-5

the albedo feedback would be muted and could be even negative if the positive global sea ice converage continues.

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John Christy’s Comment On “If You Want To Roll The Climate Dice, You Should Know The Odds”

In response to the post yesterday

Debate On The “Climate Dice” Issue

with respect to the post on The Conversation

If you want to roll the climate dice, you should know the odds

John R. Christy, Distinguished Professor of Atmospheric Science and Director of the Earth System Science Center of the Univeristy of Alabama in Huntsville, has provided us with his perspective on the Conversation post.

Following is John’s insightful comment.

To make an apples to apples comparison between the 1981 paper by Hansen and observations since 1979, a couple of adjustments need to be made. Without these adjustments, the comparisons are apples to oranges and conclusions misleading.

Eyeballing the forecast curve gives a model projected surface trend of about +0.15 C/decade since 1979.  I suspect the rise in CO2 was actually faster, and thus this curve underestimates what the model would have shown had it used better emissions numbers.

This +0.15 C/decade is a surface trend, so to compare with GISS model troposphere, the scaling factor is 1.25, giving a 1981 model trend of +0.19 C/decade.  That’s one adjustment.

The second adjustment is to account for the volcanic cooling in the first part of the 1979-2012 observations which tilts the observed trend to be more positive than otherwise by about +0.04 C/decade.  So had the 1981 model included real volcanoes which cooled the early portion, its tropospheric trend would be tilted upward to about +0.23 C/decade.  This compares with observations of UAH and RSS of +0.13 C/decade.  So, the apples to apples comparison with tropospheric temperatures since 1979 would be, model: +0.23 C/decade, observations +0.13 C/decade.

Now if we start after the effects of Mt. Pinatubo (say around 1996) to avoid having to calculate the volcanic impact, we have the following. The model goes from +0.2 to +0.5 in 16 years (i.e. trend of about +0.19 at the surface or +0.23 C/decade in the troposphere) while observations show UAH +0.11 C/decade and RSS +0.04 C/decade.  Quite a difference between models and observations!

As an interesting footnote, the average climate model for the most recent CMIP-5 RCP4.5 result has a calculated tropospheric trend of +0.22 C/decade for 1979-2012 and +0.29 C/decade for 1996-2012.  So, not much has changed in 30 years as far as model skill in replicated tropospheric trends it seems.

John C.

source of image

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Debate On The “Climate Dice” Issue

source of image from Revkin.net

There is an informative discussion ongoing at the weblog

The Conversation

regarding the “climate dice” issue that Jim Hansen has introduced. As written on The Conversation in their post on April 17 2012 by Ben Newell who is an Associate Investigator at the ARC Centre of Excellence in Climate Systems Science;

If you want to roll the climate dice, you should know the odds

This “climate dice” analogy has been used in a recent paper by James Hansen and colleagues to demonstrate how over the past 30 years the dice have become “progressively loaded”. There is no longer equal chances of warm, cool, or average seasons.

I was asked on this weblog to respond to the comment in the following e-mail

 Dear Dr Pielke and Dr Hansen,  I would be interested in comments from both of you for public posting  concerning the following comments made on an Australian website called The  Conversation.

See comments at  https://theconversation.edu.au/if-you-want-to-roll-the-climate-dice-you-should-know-the-odds-6462#comment_32628

Specifically Dr Hansen’s 1981 paper was mentioned to provide credence to  the suggestion that climate models are performing skillfully. I note this  paper has received some attention in the press recently and resulted in a  blog post by Dr Pielke Snr pointing out the following about the model  outputs:

“If the observed surface temperature data used in the figure in which this  claim is made is correct, but also so is the measurement of lower  tropospheric temperatures (such as from MSU RSS and MSU UAH), than Hansen’s  forecast for the surface temperatures would be correct, but for the wrong  reason. If the warming were due to added CO2 and other greenhouse gases,  the lower tropospheric temperatures would have warmed at least as much.

However, the latest available global average lower tropospheric temperature  anomaly (see) is only +0.11 C above the 30 year average. Over this time  period, the Hansen figure shows an expected change anomaly of ~+0.5c.

The trend has also been essentially flat since 2002. The Hansen figure  indicates the current change since 2002 should be almost +0.2C.”

For the rest of the article from which the above is derived see…

http://pielkeclimatesci.wordpress.com/2012/04/13/cherrypicking-a-comment-on-the-atlantic-article-now-this-is-interesting-a-climate-prediction-from-1981-by-james-fallows/

The following response [by Nick Kermode] to this was elicited at The Conversation:

Marc, Mr. Pielke Snr. would have done well to actually read Hansens paper  rather than just a newspaper article. Making a statement like “If the  warming were due to added CO2 and other greenhouse gases, the lower  tropospheric temperatures would have warmed at least as much” shows he  clearly hasn’t. In his paper Hansen specifically says the troposphere  should not have responded yet. So his temp. predictions are pretty close  and he is ALSO right about the troposphere. Have a read, amazing it was  written 30 years ago!  https://theconversation.edu.au/if-you-want-to-roll-the-climate-dice-you-should-know-the-odds-6462#comment_32633

Can either of you comment. Dr Hansen I cannot find anywhere in your paper  reference to  a statement that suggest “the troposphere should not have  responded yet“. Indeed it seems this would go against the basic science for  a transient response to increased CO2.

Regards  Marc Hendrickx

My reply, posted on The Conversation, was

Hi Mr. Hendrickx

Thank you for the opportunity to add to the discussion. The troposphere clearly should not have a lag in the heating, as we discuss, for instance in our papers

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841. http://pielkeclimatesci.files.wordpress.com/2009/11/r-345.pdf

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2010: Correction to: “An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841″, J. Geophys. Res., 115, D1, doi:10.1029/2009JD013655. http://pielkeclimatesci.files.wordpress.com/2010/03/r-345a.pdf

As we report in the second paper, Gavin Schmidt, who works with Jim, has provided online model results of an amplification of 1.1 over land and 1.6 over the oceans. The surface and lower troposphere are clearly connected in terms of warming in the model results.

Jim also wrote in

http://pielkeclimatesci.files.wordpress.com/2009/09/1116592hansen.pdf

in a response to a comment by John Christy and I in 2005 [http://pielkeclimatesci.files.wordpress.com/2009/09/hansen-science.pdf]

that

“The Willis et al. measured heat storage of 0.62 W/m2 refers to the decadal mean for the upper 750 m of the ocean. Our simulated 1993-2003 heat storage rate was 0.6 W/m2 in the upper 750 m of the ocean. The decadal mean planetary energy imbalance, 0.75 W/m2, includes heat storage in the deeper ocean and energy used to melt ice and warm the air and land. 0.85 W/m2 is the imbalance at the end of the decade.”

The end of the decade refers to the 1990s. If this finding were robust, we would expect heating to occur in the lower troposphere in recent years.

Please let me know if you would like further input on this question.

Best Regards

I look forward to seeing how Jim Hansen (or Gavin Schmidt) responds to Marc’s inquiry, and will post if they do.

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