Climate Science: Roger Pielke Sr. Research Group News

Professor Chris Castro alerted us to the following paper;

Barnett, T. P, and D. W. Pierce, 2008: When will Lake Mead go dry? Water Resour. Res., 44, W03201, doi:10.1029/2007WR006704.

The abstract reads

“A water budget analysis shows that under current conditions there is a 10% chance that live storage in Lakes Mead and Powell will be gone by about 2013 and a 50% chance that it will be gone by 2021 if no changes in water allocation from the Colorado River system are made. This startling result is driven by climate change associated with global warming, the effects of natural climate variability, and the current operating status of the reservoir system. Minimum power pool levels in both Lake Mead and Lake Powell will be reached under current conditions by 2017 with 50% probability. While these dates are subject to some uncertainty, they all point to a major and immediate water supply problem on the Colorado system. The solutions to this water shortage problem must be time-dependent to match the time-varying, human-induced decreases in future river flow.”

The text includes the statements

“We consider human-induced reductions in runoff of 10 to 30%, in accordance with estimates from global climate models and statistical analysis, and take these reductions to be linear in time over the next 50 years (i.e., runoff slowly decreases until it reaches a total reduction of, say, 10% below current levels in 2057)”;

“….we begin with deterministic estimates of when the live storage will be depleted by global warming-driven runoff reductions alone, without the outside impacts of evaporation and natural variability in the river flow”;

“The climate models which have produced estimates of decreasing runoff have a host of problems of their own in handling the water budget from coarse resolution (little in the way of Rocky Mountains) to the variety of ways they handle soil processes and vegetation representations. However, a recent study of changes in hydrology of the western U.S. over that last 50 years shows several of the models, when run with observed anthropogenic forcings, reproduce extremely well the observed changes in river flow timing, snow pack decline and increasing air temperatures in the western United States [Barnett et al., 2008]. So these models, while not perfect, have a message to tell; a message supported by their ability to reproduce well the last 50 years of multivariate hydrological observations“;

and 

“…..the Colorado River will continue to lose water in the future, if the global climate models are correct.”

This paper correctly identifies that there is risk associated with the limited water available from the Colorado River. Indeed their statement that

“Tree ring data suggest the long term flow of the Colorado experiences more variability than has been observed over the last century [NAS, 2007]. These data also suggest prolonged droughts far worse and more extensive than seen in the last 100 years of flow record on the River are possible”

shows that the water resource is at risk regardless of how humans have altered the system. This is a conclusion we also reached in our paper

 Pielke Sr., R.A., N. Doesken, O. Bliss, T. Green, C. Chaffin, J.D. Salas, C. Woodhouse, J.L. Lukas, and K. Wolter, 2005: Drought 2002 in Colorado - An unprecedented drought or a routine drought?Pure Appl. Geophys., Special Issue in honor of Prof. Singh, 162, 1455-1479, doi:10.1007/200024-005-2679-6.

However, the paper suffers from their reliance on the multi-decadal global models as quantitative predictions of what will happen in terms of climate in the coming years. They even recognize this in their text “…..the Colorado River will continue to lose water in the future, if the global climate models are correct.” 

Thus while Climate Science agrees that there is a significant concern on water available from the Colorado River, and planning should be a major priority with respect to long-term drought, the multi-decadal global model predictions are just hypotheses and their use as part of the computation as definitive, skillful predictions to present quantitative probabilities of Lake Mead drying out is misleading to the policymakers. This is yet another example of overselling the skill that exists in using these models as predictions. The large amounts of precipitation this past winter (2007-2008) in large areas of the West should be a wake-up call on the serious limitations of the IPCC models.

There is a remarkable quote on the Nature.com blog website . On that website it is written

“The NY Times wraps up its main piece [by Andy Revkin] with a useful quote from Kevin Trenberth, of the US National Center for Atmospheric Research: ‘Too many think global warming means monotonic relentless warming everywhere year after year. It does not happen that way.’”

This is an amazing error.  Global warming does require a more-or-less monotonic increase in warming (in the absence of a  major volcanic eruption) as illustrated in all available multi-decadal global model runs (e.g. see the Figure in this post on Climate Science ; and see Figure 1 in Barnett et al, 2001). This essentially monotonic report is even emphasized in the 2007 IPCC Summary for Policymakers (see Figure SPM.4)!

Climate Science published a proposed test of the multi-decadal global model predictions (see A Litmus Test For Global Warming - A Much Overdue Requirement).  Clearly, so far, the models are failing to skillfully predict the rate (and even the sign for the most recent years) of global warming. Andy Revkin should follow up his article to document what the models predict in terms of global warming (in Joules) over different time periods, and what do the observations actually show. This would be excellent investigative (much needed) journalism.

There has been a renewed discussion of the relevance of the “butterfly effect” to describe the actual effect of the flapping of a butterfly wing on large-scale weather (on Real Climate see and on Climate Science see and see).

There is an important research issue with respect to the size of a perturbation of the atmosphere that must occur before it can have any effect on the larger-scale atmosphere. Ray Pierrehumbert and Gavin Schmidt on Real Climate conclude that there is no minimum spatial scale, while Issac Held states that features must be larger than a few millimeters.

Rich Eykholt and I have agreed to complete a paper on this subject over the coming months, as it clearly is an issue that has been neglected, and, in my view, is a misinterpretation of the conclusions from the seminal work of Ed Lorenz.

The real butterfly is illustrated below  

[from http://en.wikipedia.org/wiki/Chaos_theory]

“The Lorenz attractor is a 3-dimensional structure corresponding to the long-term behavior of a chaotic flow, noted for its butterfly shape. The map shows how the state of a dynamical system (the three variables of a three-dimensional system) evolves over time in a complex, non-repeating pattern.  Picture below is a plot of the Lorenz attractor for values r = 28, σ = 10, b = 8/3.”

from http://en.wikipedia.org/wiki/Chaos_theory

The interested reader can also evaluate the solution for different input values at  http://crossgroup.caltech.edu/chaos_new/Lorenz.html

In terms of what Professor Lorenz wrote, following is the text from his book The Essence of Chaos by Ed Lorenz in 1993 (from pages 14 and 15) regarding the expression “The Butterfly Effect”. The Figure 2 that he refers to in the text is of the form of the above two figures, and he labels it as “The butterfly”! Professor Lorenz wrote

“The expression has a somewhat cloudy history. It appears to have arisen following a paper that I presented at a meeting in Washington in 1972 entitled “Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?”  I avoided answering the question, but noted that if a single flap could lead to a tornado that would not otherwise have formed, it could equally well prevent a tornado that would otherwise have formed. I noted also that a single flap would have no more effect on the weather than any flap of any other butterfly’s wings, not to mention the activities of other species, including our own.  The paper is reproduced in its original form as Appendix A.

The thing that has made the origin of the phrase a bit uncertain is a peculiarity of the first chaotic system that I studied in detail.  Here an abbreviated graphical representation of a special collection of states known as a “strange attractor” was subsequently found to resemble a butterfly, and soon came to be known as the butterfly.   In Figure 2 we see one butterfly; a representative of a closely related species appears on the inside cover of Gleick’s book.  A number of people with whom I have talked have assumed that the butterfly effect was named after this attractor.  Perhaps it was.

Some correspondents have also called my attention to Ray Bradbury’s intriguing short story, “A Sound of Thunder,” written long before the Washington meeting.  Here the death of a prehistoric butterfly, and its consequent failure to reproduce, change the outcome of a present-day presidential election.

Before the Washington meeting, I had sometimes used a sea gull as a symbol for sensitive dependence.  The switch to a butterfly was made by the session convenor, the meteorologist Philip Merilees, who was unable to check with me when he had to submit the program titles. Phil has recently assured me that he was not familiar with Bradbury’s story. Perhaps the butterfly, with its seeming frailty and lack of power, is a natural choice for a symbol of the small that can produce the great.

Other symbols have preceded the sea gull. In George W. Stewart’s novel Storm, a copy of which my sister gave me for Christmas when she first learned I was to become a meteorology student, a meteorologist recalls his professor’s remark that a man sneezing in China may set people to shoveling snow in New York.  Stewart’s professor was simply echoing what some real-world meteorologists had been saying for many years, sometimes facetiously, sometimes seriously.”

Thus, the butterfly effect, which is described by the solution shape in the above figures, has morphed into a symbol that small perturbations can alter large-scale structure.

However, scientists such as Ray Pierrehumbert and Gavin Schmidt at Real Climate have literally interpreted Professor Lorenz’s seminal as applying to all perturbations of atmospheric flow regardless of their magnitude and spatial scale.  This clearly was not the claim of Professor Lorenz.

In the real world, very small perturbations, such as the flap of a butterfly wing cannot have any impact on the large-scale flow (such as the creation of a tornado). In order to do that, the turbulence generated by the flapping wings must retain some coherant flow structure as the nonlinear interactions create larger scale structure. However, this kinetic energy is dispersed over progressively larger and larger volumes such that it will quickly dissipate into heat as the magnitude of the disturbance to the flow at any single location becomes smaller. The atmosphere has an infinitesimal addition of heat, but the coherent information needed to alter the large-scale flow is lost.

This paragraph should, of course, be viewed as a hypothesis, and we will be evaluating this in our paper. Readers, including those at Real Climate, are invited to also seek to falsify this hypothesis.

The discussion with Real Climate continues. The updated comments as of Saturday April 26 are at

Comment On Real Climate’s Post On The Relevance Of The Sensitivity Of Initial Conditions In The IPCC Models

Follow Up (April 27 2008)

Ray - In searching for what Professor Lorenz has said on this issue, please  see Chaos Avant-Garde: Memories of the Early Days of Chaos Theory

 In this essay he writes,

“Returning now to the question as originally posed, we notice some additional points not yet considered. First of all, the influence of a single butterfly is not only a fine detal - it is confined to a small volume. Some of the numerical methods which seem to be well adapted for examining the intensification of errors are not suitable for studying the dispersion of errors from restricted to unrestricted regions. One hypothesis, unconfirmed, is that the influence of a butterfly’s wings will spread in turbulent air, but not in calm air”

This certainly would rule out the butterfly in the jar! More importantly, he recognized that there remain questions about the “butterfly effect”, one of which is when small pertubations result in altering larger scale atmospheric flow, and when they do not.

Sixth Update (April 27 2008)

A Further Reply By Ray Pierrehumbett

 [Response:Roger, I can’t make sense of what you’re trying to say here. For those picokelvins of temperature to be lost to space, first they have to appear in the atmosphere as an increase of temperature, right? So there you have your change of one digit in the initial conditions, just like in Lorenz’s example. And your statement is just flatly inconsistent with thermodynamics. The butterfly dissipates heat locally, and that heat will be gradually diluted over a larger and large area. So just divide by Cp and there’s your answer. Do you think there’s some way to magically teleport the heat away, leaving the fluid to heal back to exactly the same condition it would have had without the flap? That’s really a stretch. Your remarks about simple models and GCM’s don’t make much sense to me either. The GCM doesn’t resolve butterfly-scale motions, but once you have influenced a dynamic variable (e.g. temperature) at a resolved scale, any number of actual twin experiments in GCM’s confirm the divergence. If you are claiming there’s some fundamental difference between sensitive dependence to large scale changes in a GCM and sensitive dependence in the atmosphere, I’d like to see some evidence to back up that claim. The success of GCM’s in short term weather forecasting would be pretty much impossible to reconcile with such a claim. –raypierre]

 My Reply

You are correct in that you and I probably agree on most issues in chaos and nonlinear dynamics. All NWP and climate models show the sensitivity of large scale circulation features to initial conditions when perturbations are inserted in their initial state or in their parameterizations (these are all much larger effects than the energy that a butterfly places in the system). We also agree that the added heat from a butterflies flapping wings results in a slightly different system than if this flapping did not occur. However, the issue is whether the heat (the “information”) from this effect can translate (teleconnect) to larger scale so as to result in alterations in large scale features. 

Even Issac Held seemed to indicate that there is a lower limit to when this upscale effect can occur (i.e. this ability disappears when the flow becomes laminar); he said in this thread

“the scale of the perturbation has to be larger than what is often referred to as the Kolmogorov microscale, the scale below which the flow is effectively laminar, to avoid being damped out immediately. This scale is typically a few millimeters in the atmosphere….”

I agree with this, but maintain that the smallest turbulent scales also are damped out due to the physics of non-motion transfers (i.e. radiative transfers) of energy. I have been in communication with Professor Ekyholt on this question, and he and I agree that you are misinterpreting the butterfly effect for very small scale perturbations. We will be preparing a paper on this to demonstrate that there is  lower limit to which the “butterfly effect” applies.

On a separate note, I see commenters on this thread are somehow skewing this discussion to be on climate change. It is not. This issue of the scale at which the “butterfly effect” occurs is a pure discussion of the science such as we all used to have as graduate students and need more of!

Also, you questioned as to why Roy Spencer posted a guest weblog. The answer is that he has introduced a novel and important new perspective into how variations in atmospheric/ocean circulations can result in alterations in the global average radiative balance. Disagreements with his results and conclusions should be on his science. I invite others (including any interested Real Climate climate scientist) to post unedited guest weblogs on Climate Science.  

 Additional Response From Ray  Pierrehumbert

 [Response:Regarding the butterfly in the room — even in a jar in the room — sure I think it’s likely that it would ultimately affect the large scale weather. Look at it this way: Temperature has a dynamic influence through buoyancy. The heat dissipated by the butterfly might warm the room by a few tens of microkelvins, say. That increased temperature will change the heat flow between the house and the environment, which will ultimately change the temperature of some parcel of air by a few nanokelvins. Then before you know it, some parcel of air the size of the state of Illinois has a temperature different by maybe a few picokelvins. I guarantee that if you take a GCM and change the temperature of the air over Illinois by a few picokelvins (given sufficient arithmetic precision) that that will lead to divergence of the large scale forecast given infinite time. I have seen no indication either in dynamical systems theorems or in numerical experiment to suggest that anything else would be the case. –raypierre]

My Reply

Ray- We certainly disagree with respect to the butterfly in the room in a jar.  :-). Other readers of Real Climate (and Climate Science) can make up their own minds on this.

You are, however, taking the concept of chaos too narrowly and are focusing on idealizations (simple illustrative models and GCMs) of  how the real atmosphere (and climate system) works. You are ignoring the consequences of the dissipation of kinetic energy into heat within a open system. The “picokelvins” of heat, even if they could cause such a temperature perturbation over the state of Illinois (which it would not), would be lost to space long before an “infinite” time were reached.

Fourth Update (April 26 2008)

 Additional Response From Ray  Pierrehumbert

[Response:Have a look at Isaac’s remark above. I think what you probably have in mind is the possibility that if a perturbation is at a scale where you have primarily downscale energy cascade to the dissipation range, it might never project on the large scale quantities whose behavior determines large scale predictability loss. Given the nature of turbulence, it is hard to absolutely exclude this possibility a priori, but for this to happen, there would have to be ZERO leakage to large scales. Not just small but ZERO. That is exceedingly unlikely, and would be contrary to most of what is know about turbulent cascades. As a practical matter, I do agree that if the initial perturbation is at sufficiently small scales, the projection on large scales would be small enough that it could take an exceedingly long time before it affected the evolution of the large scales. –raypierre]

My Reply [posted on Real Climate]

Ray - Thank you for getting involved in this discussion.  The question of the leakage time scale is, of course needed, in order to determine when the exceedingly long time scale becomes infinite (in terms of where the heat goes).  If we both agree that ALL of the turbulence quickly dissipates into heat when the flapping stops, then what is your estimate of the residence time of this heat within the atmosphere before it is lost to space?

Also, as another thought example, if a butterfly flaps its wings inside a room with the doors shut, would you still maintain that this has an influence on atmospheric circulation at large distances? All of the heat generated would be absorbed by the walls of the room, and subsequent heat conduction is, of course, laminar.  An analogous behavior will occur in a very stable boundary layer (and any region of the atmosphere for such small perturbations), and if we can agree on this “exception” than we have made progress in understanding this issue. My point here is that if there is an part of the process which results in complete loss of the turbulent flow, then it is not communicated over large distances.

Issac’s Held’s answer also actually contains part of the answer on this issue.  If the turbulence dissipates into heat, as  illustrated in the above example,  than its further behavior can be described by non-turbulent behavior. As he explained, he was “was thinking that the scale of the perturbation has to be larger than what is often referred to as the Kolmogorov microscale, the scale below which the flow is effectively laminar, to avoid being damped out immediately. This scale is typically a few millimeters in the atmosphere “.  This is what occurs with the flapping of the wings of a butterfly; all of its energy dissipates into heat and the spatial structure of this heated air is less than a few mm.  To disprove this total transfer downscale, one would have to show that a coherent turbulent structure remains  and becomes progressively larger in scale and/or is monitored propagating away from the location of the flapping wings as a coherent disturbance of the air flow; in both cases,  while still retaining the conservation of total energy.  Since the total energy of the flaps of the butterfly’s wings must be accounted for (as kinetic energy in the turbulence, heat) what is your estimate of the magnitude of this energy that reaches thousands of kilometers away, as well as the path this energy would take to get there?

Third Update (April 25 2008)

Further Response From Gavin Schmidt

 Response: As we said above, this is what you believe. Why you accused us of misrepresenting you is a mystery. However, your claim about Ekykholt’s belief is contradicted by his quote above. He states very specifically that exponential growth saturates at the time the perturbation reaches the size of the attractor. That, for the atmosphere, is very large indeed and is certainly large scale enough to encompass storms thousands of miles away. Isaac can certainly speak for himself, but as far as I know there is no demonstration that there is a minimum scale below which perturbations do not grow. Such a thing may exist, but your certainty on the matter seems a little overconfident. Perhaps you’d care to point out a reference on the subject? - gavin]

 My Reply [posted on Real Climate] Gavin  - I am glad this discussion is continuing. I will be having more to say on this next week in a weblog on Climate Science, however, you are failing to distinguish between an open and closed system, and between the real world and models.  With nonlinear atmospheric models such as analyzed by Professor Lorenz, the results for large scale features are sensitive to the initial conditions regardless of how small they are. This is because the system is closed.  The real world climate system, however, is not closed, such that energy (i.e. in the form of heat) can leak out of the system.  In the case of such a small perturbation as the flap of a butterfly wing, the kinetic energy of the small amount of turbulent air that it generates will quickly dissipate into heat, once the flapping stops. Radiative loss of this heat to space will prevent the flapping to have any effect at large distances.  

This is one of the reasons that you are mistaken in stating that “there is no demonstration that there is a minimum scale below which perturbations do not grow.” If a perturbation in the system (i.e. the atmosphere) dissipates into heat, it can be lost to the system before affecting atmospheric features at large distances. I will have more on this topic on my weblog next week, and will post a comment on Real Climate when it appears.

Second Update (April 24 2008)

 Gavin Schmidt has replied

Response:You misinterpreted this back on the original thread and you are misinterpreting it here again. However, just repeating the same argument is pointless. Since I agree with Dr. Eykholt’s statement, and so do you, let’s just leave it at that. (if other readers are interested in what this is about, please go to the original thread. The clue is that ‘larger scales’ in the Eykholt quote means the attractor itself (i.e. climate), while RP thinks he means the large scale flow (i.e. the specific position on the attractor)). - gavin]

and 

My Response is

 Gavin- I agree readers can go through the thread to see the discussion. However, you are misrepresenting my views. Rich Eykholt and I are in 100% agreement on this subject. The question that was being discussed is whether an atmospheric perturbation as small as a real world butterfly could actually affect large scale weather features thousands of kilometers away. The answer, as given by Professor Eykholt, is NO under any circumstance. The perturbation has to be much larger (Issac Held, as I recall said meters in his NPR interview; I suspect it is a few kilometers or more) for a perturbation to affect an atmospheric feature thousands of kilometers away.

This issue, based on our disagreement, would benefit from further quantitative evaluation with both analytic and numerical models. We do have papers on the use of analytic models to examine chaos and nonlinear dynamics which document that we are quite familiar with the subject of sensitivity of the climate system to initial conditions; e.g. see

Pielke, R.A. and X. Zeng, 1994: Long-term variability of climate. J. Atmos. Sci., 51, 155-159.
http://climatesci.colorado.edu/publications/pdf/R-120.pdf

Update (April 24 2008)  : Following is my comment, Gavin Schmidt’s reply, and my response on Real Climate

 Roger A. Pielke Sr. Says:
23 April 2008 at 10:15 AM

Please see http://climatesci.org/2008/04/23/comment-on-real-climates-post-on-the-relevance-of-the-sensitivity-of-initial-conditions-in-the-ipcc-models/

[Response:In the linked piece, you very clearly state that you do not believe that the real world is sensitive to initial condition variations like butterflies. That is all we are discussing here. If you now think that it is, feel free to expound on your viewpoint. We were just trying to make sure that a diversity of points was presented. - gavin]

My Reply: 

Gavin - Thank you for posting my Climate Science link. In terms of actual butterlies, this is clearly explained by an expert in the physics and mathematics of nonlinear dynamics and chaos in geophysical flows, Professor Richard Eykholt (see http://climatesci.org/2005/10/12/more-on-the-butterfly-effect/), where he writes “

Roger: I think that you captured the key features and misconceptions pretty well. The butterfly effect refers to the exponential growth of any small perturbation. However, this exponential growth continues only so long as the disturbance remains very small compared to the size of the attractor. It then folds back onto the attractor. Unfortunately, most people miss this latter part and think that the small perturbation continues to grow until it is huge and has some large effect. The point of the effect is that it prevents us from making very detailed predictions at very small scales, but it does not have a significant effect at larger scales. 

Richard Eykholt”

Original Post

Real Climate has published a well written summary of the seminal accomplishments of Professor Ed Lorenz in the field of deterministic chaos and nonlinear dynamics (see). Professor Lorenz’s contribution to the understanding of the mathematics and physics of geophysical flows (and other dynamic systems) has altered how the science community investigates these processes. I had the opportunity to sit and talk with Professor Lorenz during one of his trips to Colorado State University, and enjoyed and learned from his perspective on the nonlinear aspects of the climate system including its behavior, as with any other nonlinear system with strong feedbacks, as being sensitive to initial conditions.

At the end of the well deserved recognition to Professor Lorenz, Real Climate writes

“So what does this have to do with the IPCC?”

Real Climate then writes

“Even though the model used by Lorenz was very simple (just three variables and three equations), the same sensitivity to initial conditions is seen in all weather and climate models and is a ubiquitous phenomenon in many complex non-linear flows. It is therefore usually assumed that the real atmosphere also has this property. However, as Lorenz himself acknowledged in 1972, this is not directly provable (and indeed, at least one meteorologist doesn’t think it does even though most everyone else does). Its existence in climate models is nonetheless easily demonstratable. “

I am the “one meteorologist”.  Real Climate refers to one of the Climate Science weblogs on this issue that was published (see).

However, Real Climate is wrong in its statement on my research conclusions!  I have written several papers on climate as an initial value problem: e.g. see

Pielke, R.A., 1998: Climate prediction as an initial value problem. Bull. Amer. Meteor. Soc., 79, 2743-2746.

Pielke Sr., R.A., G.E. Liston, J.L. Eastman, L. Lu, and M. Coughenour, 1999: Seasonal weather prediction as an initial value problem. J. Geophys. Res., 104, 19463-19479.

Rial, J., R.A. Pielke Sr., M. Beniston, M. Claussen, J. Canadell, P. Cox, H. Held, N. de Noblet-Ducoudre, R. Prinn, J. Reynolds, and J.D. Salas, 2004: Nonlinearities, feedbacks and critical thresholds within the Earth’s climate system. Climatic Change, 65, 11-38.

Real Climate should report  accurately on the research of others.

What we disagree on is whether the multi-decadal global climate model predictions can be used to accurately quantify the degree of nonlinearity and predictability of the real world climate system (the nonlinearity of the climate system is shown, for example, in the Rial et al paper).

Real Climate, however, reports on the use of a model to investigate this issue. This is a typical mistake they are making; a model is itself a hypothesis and cannot be used to prove anything! The multi-decadal global model simulations only provide insight into processes and interactions, but we must use real world data to test the models. So far, the models have failed, for example,  in their ability to accurately predict the regional weather and climate features we discuss in the Rial et al paper. Lets have more accurate reporting on Real Climate.

There was a Hearing on Climate Change and Deforestation in the U.S. Senate yesterday (April 22 2008) [Thanks to Dev Niyogi of Purdue for alerting me to this Hearing].  There will be a presentation of the results so far on the excellent Vulcan project, which Climate Science weblogged on last week (see). 

Senator Lugar starts his testimony with the text

 ”I thank the Chairman for holding this important hearing.  A year ago today, I was on my farm in Marion County, Indiana, for a ceremony recognizing the role of agriculture and forestry in mitigating the social, economic, and political threats posed by climate change.  I was joined by Richard Sandor, Chairman and CEO of the Chicago Climate Exchange, and Tom Buis, President of the National Farmers…, to promote how certain no tillage agricultural practices and forestry can sequester carbon dioxide and help offset the environmental threats from excessive carbon emissions.”

Later he writes,

 ”Clearly, there are economic opportunities in clean energy sources, solar, wind and biofuels, and carbon sequestration and storage technologies.  But improvements in farming and forestry practices may be among the lowest hanging fruit in the quest to deal with climate change.”

The planting of trees certainly should be encouraged for a variety of reasons. However, Senator Lugar has not adequately communicated the following issues:

• The conversion of the landscape by deliberate management practices, is itself a climate change forcing (Kabat et al, 2004; NRC, 2005; Feddema et al, 2005; Pielke 2005).
• The net effect of deliberate landscape change such as afforestation may actually result in a radiative warming effect even though CO2 is extracted from the atmosphere by the plants. This occurs if the resulting surface albedo is less than for the original landscape and due to the added water vapor that is transpired into the atmosphere from the vegetation (i.e. see Pielke Sr., R.A., 2001: Carbon sequestration — The need for an integrated climate system approach. Bull. Amer. Meteor. Soc., 82, 2021.). [Update: Thanks to Barry Hearn for alerting us to two typos in this paragraph!]

Further discussion of these issues is in the papers

Pielke Sr., R.A., G. Marland, R.A. Betts, T.N. Chase, J.L. Eastman, J.O. Niles, D. Niyogi, and S. Running, 2002: The influence of land-use change and landscape dynamics on the climate system- relevance to climate change policy beyond the radiative effect of greenhouse gases. Phil. Trans. A. Special Theme Issue, 360, 1705-1719.

Marland, G., R.A. Pielke, Sr., M. Apps, R. Avissar, R.A. Betts, K.J. Davis, P.C. Frumhoff, S.T. Jackson, L. Joyce, P. Kauppi, J. Katzenberger, K.G. MacDicken, R. Neilson, J.O. Niles, D. dutta S. Niyogi, R.J. Norby, N. Pena, N. Sampson, and Y. Xue, 2003: The climatic impacts of land surface change and carbon management, and the implications for climate-change mitigation policy. Climate Policy, 3, 149-157.

 Unless these issues are addressed in the context of developing climate policy that includes rewards for landscape management, the desired goal of reducing the human impact on climate will not be achieved.

There is an interesting exchange of views by Bill Gray, Tom Knutson and Steve Lyons at the Bahamas Weather Conference (Thanks to Bob Ferguson for alerting us to this short video.

Climate Science has just one comment on this video. Tom Knudson claims that the global climate models can be used to test theory (such as his claim on the dominance of CO2 as the driver of climate change).

However, Tom Knudson makes the very serious mistake of stating that models can test his claim.  The models are hypotheses and cannot test anything! They can be used to improve our understanding of how a system works, but their results must be tested against real-world observational data.

His failure to properly communicate what models really should be used for, unfortunately, permeates popular and media preceptions of the climate change issue, and is resulting in very poor policy decisions (e.g., see the April 15th, 2008 post on Prometheus entitled “Biofuels and Mitigation/Adaption” ).

There continues to be misunderstandings on my viewpoint on the role of humans within the climate system. This weblog is written to make sure it is clear, and can be used whenever someone asks the question as to where does Pielke Sr. stand on this issue.

 As I have written in the Main Conclusions of Climate Science

“Humans are significantly altering the global climate, but in a variety of diverse ways beyond the radiative effect of carbon dioxide. The IPCC assessments have been too conservative in recognizing the importance of these human climate forcings as they alter regional and global climate.”

and that

“Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.”

These conclusions are different from those who claim that the global average radiative effect of carbon dioxide is by far the major human climate forcing, as well as from those who conclude that natural climate variations dominate climate change and that the human climate forcings are inconsequential.

My viewpoint is also well articulated in

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

and you are encouraged to read the Executive Summary of that report [a report which whas been ignored by the media despite its broad base of authorship and its extensive review before it was published].

The reason that  that those who focus on the global average radiative forcing of carbon dioxide are missing the bulk of human climate forcings include the following:

1. Atmosphere and ocean circulations respond to regional forcings not a global average (e.g. see and see)

2. The other human climate forcings include

• the diverse influence of human-caused aerosols on regional (and global)  radiative heating (e.g. see).
• the effect of aerosols on cloud and precipitation processes (e.g. see)
• the influence of aerosol deposition on climate (e.g. see and see)
• the effect of land cover/ land use on climate (e.g. see and  see)
• the biogeochemical effect of added atmosopheric CO2 has a greater effect on the climate system than the radiative effect of added CO2 (e.g. see).

Natural climate variations and change, have also been underestimated (and are only poorly understood) based on examination of the historical and paleo-climate record (e.g. see and see).

Human climate forcings have a more significant role in altering the weather than does a global average increase in the radiative effect of an increase in the atmospheric concentration of CO2.  This does not mean that we should not work to limit the increase of this gas in the atmosphere, but it is not the dominate climate forcing that affects society and the environment.

Policies that focus on CO2 by itself are ignoring definitive research results (such as reported in the 2005 National Research Council report) that humans have a much broader influence on the climate system than was communicated in the 2007 IPCC report.  To neglect these other climate forcings represents a failure by policymakers (and the media) to utilize this scientifically robust information.

The neglect of including the diversity of human climate forcings indicates that the real objective of those promoting the radiative effect of  the addition of atmospheric CO2 as the dominate human climate forcing is to promote energy and lifestyle changes. Their actual goal is not to develop effective climate policies. 

The news reports on the breaking off of a portion of floating ice in Antarctica have received wide distribution (i.e. do a google search under news for Antarctic sea ice and hundreds of reports appear on this event). These news reports claim that this breaking is due to global warming. As just one example of the statements in the news, The Guardian wrote 

 ”The collapsing shelf suggests that climate change could be forcing change much more quickly than scientists had predicted.

“The ice shelf is hanging by a thread,” said Professor David Vaughan of the British Antarctic Survey (BAS). “We’ll know in the next few days or weeks what its fate will be.”

The Wilkins shelf covers an area of 5,600 square miles (14,500 sq km). It is now protected by just a thin thread of ice between two islands.

Vaughan was a member of the team that predicted in 1993 that global warming could cause the Wilkins shelf to collapse within 30 years.”

This media reporting has become typical of the bias that many journalists have. Not reported in the media (but well reported on ICECAP by Joe D’Aleo)  the media has ignored in their reporting the increase in Antarctic sea ice cover in recent years, with, at present, a coverage that is well over 1 million square kilometers above average (see)!

In fact, over the globe, since the Arctic sea ice cover is not far below its average and the Antarctic sea ice coverage is well above average for this time of the year, the global coverage of sea ice is actually above average after being below last year (see). There is no way to know if this is just a short term perturbation, but at the very least the news media should have been honest and balanced in their coverage.

Unfortunately, it appears that most journalists just parrot the perspective of the first news release on these climate issues, without doing any further investigation. If this is inadvertent, they need to be educated in climate science. If deliberate bias, they are clearly advocates and the reporters should be clearly and publically identified as having such a bias. In either case, the public is being misinformed!

On March 20 2008, the Associated Press reporter Seth Borenstein published a news report titled “Global Warming Rushes Timing of Spring“.  This article, unfortunately perpetuates the inaccurately narrow perspective that only “global warming” can produce an earlier greening up in the spring. Indeed, even though some areas are greening up later, the article has the audacity to write

 ” In much of Florida and southern Texas and Louisiana, the satellites show spring coming a tad later, and bizarrely, in a complicated way, global warming can explain that too, the scientists said.”

Thus, everything is attributable to “global warming”.

 This inaccurate characterization of climate science ignores the following issues:

1. Plants only know about their immediate microclimate. They are not a metric of global warming, but only whether local conditions are conducive to earlier green-up. This can clearly occur due to landscape change in the vicinity of the plants, thus this issue needs to be considered in any explanation of changes in phenology.

2. The biogeochemical effect of higher atmospheric concentrations of CO2 (both in the background atmosphere, and, if in an urban or suburban region, the local enhancement of CO2 levels)  can alter plant phenology. We found, for example, that the biogeochemical addition of added CO2 has a larger effect on temperatures and precipitation than the radiative effect of the added CO2 (in a regional model simulation);

 Eastman, J.L., M.B. Coughenour, and R.A. Pielke, 2001: The effects of CO2 and landscape change using a coupled plant and meteorological model. Global Change Biology, 7, 797-815.

3. The biogeochemical effect of human caused nitrogen deposition can significantly effect plant responses including phenology. Nitrogen deposition is a major issue, as reported on Climate Science;

Further Evidence of the Role of Nitrogen Deposition as a First-Order Climate Forcing

Is Nitrogen Deposition a First-Order Climate Forcing?

4. Land fragmentation due to human land management is well known to alter bird, insect and other animal migration, reproductive and other activites as well as to introduce invasive species which significantly alter the local and regional ecosystems; e.g. see

Plant diversity- Another Climate Metric

If Seth Borenstein really wanted to do balanced news reporting, he would have addressed these other issues in his article, before advocating “global warming” as the cause for the change in phenology of vegetation in the spring. Instead, the AP news story is yet another example of the misuse of science to promote the inaccurately narrow perspective that global warming is the main culprit whenever an environmental change is observed.