Monthly Archives: December 2010

An Example of Why Regional Weather Patterns Are More Important Than A Global-Average Temperature Anomaly

There is an informative article on Bloomberg News this morning titled

Snow Extends Europe Travel Chaos; UK Seeks Advice on Winter

Excerpts read

“Snow forced European airports including London Heathrow to scrap flights for a fourth day, prompting Britain to seek scientific advice on whether the heaviest early falls in 17 years show winter is turning colder.”

“Britain will ask its chief scientific adviser if blizzards that began a month ago, coupled with the worst cold snap in two decades last winter, provide evidence for a “step change” that would justify increased spending on cold-weather gear…”

“‘If we’re going to face week after week of these kinds of conditions, which I haven’t seen in my lifetime in this country, we’ll have to have different equipment, different procedures in the future,’ BAA Chief Executive Officer Colin Matthews said in an interview on Bloomberg Television”

What this article documents is that regional atmospheric circulations, rather than an annual global average temperature trend, matter in terms of the weather that directly affects society.  Even with the current global temperature anomaly above its long-term average (e.g. see), extreme cold weather (now for several winters in western Europe) will occur.

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Filed under Climate Science Reporting

Diagnosis of Local Land-Atmosphere Feedbacks in India By Tuinenburg Et Al 2010

There is an important new paper that further documents the major role of land cover/land use as a component within the climate system. It is

O. A. Tuinenburg  R. W. A. Hutjes C. M. J. Jacobs P. Kabat, 2010: Diagnosis of Local Land-Atmosphere Feedbacks in India
 J of Climate (in press).

The abstract reads

“Following the convective triggering potential-humidity index (CTP-HIlow) framework by Findell and Eltahir (2003a), the sensitivity of atmospheric convection to soil moisture conditions is studied for India. Using the same slab model as Findell and Eltahir, atmospheric conditions in which the land surface state affects convective precipitation are determined. For India, CTP-HIlow thresholds for land surface-atmosphere feedbacks are shown to be slightly different than for the USA.

Using atmospheric sounding data from 1975-2009, the seasonal and spatial variations in feedback strength have been assessed. The patterns of feedback strengths thus obtained have been analyzed in relation to the monsoon timing. During the monsoon season, atmospheric conditions where soil moisture positively influences precipitation are present about 25% of the time. During onset and retreat of the monsoon, the South and East of India show more potential for feedbacks than the North. These feedbacks suggest that large scale irrigation in the South and East may increase local precipitation.

In order to test this, precipitation data (from 1960-2004) of the period of about three weeks just before the monsoon onset date has been studied. A positive trend in the precipitation just before the monsoon onset is found for irrigated stations. It is shown that for irrigated stations, the trend in the precipitation just before the monsoon onset is positive for the period 1960-2004. For non-irrigated stations, there is no such upward trend in this period. The precipitation trend for irrigated areas might be due to a positive trend in the extent of irrigated areas, with land-atmosphere feedbacks inducing increased precipitation.”

The conclusion contains the text

“We conclude that the CTP-HIlow framework is a good method to efficiently determine the potential for local land-atmosphere feedbacks. Periods and regions where feedbacks are potentially important can be determined easily. Because of the limitations in the framework, a three dimensional model that takes into account more processes should be used to study the land atmosphere feedbacks in more detail. This is beyond the scope of the present paper and is a subject of further study.”

There are other papers that support their findings. These are

Niyogi, D., C.M. Kishtawal, S. Tripathi, R. S. Govindaraju, 2010, Observational Evidence that agricultural Intensification and land use change may be reducing the Indian Summer Monsoon Rainfall, Water Resources Research, 46, 3, doi:10.1029/2008WR007082, 2010.

Kishtawal C., D. Niyogi, M. Tewari, R. A. Pielke Sr., and M. Shepherd, 2010, Urbanization Signature in the Observed Heavy Rainfall Climatology over India, International Journal of Climatology, 30, published online Wiley InterScience DOI: 10.1002/joc.2044

Douglas, E.M., D. Niyogi, S. Frolking, J.B. Yeluripati, R. A. Pielke Sr., N. Niyogi, C.J. Vörösmarty, and U.C. Mohanty, 2006: Changes in moisture and energy fluxes due to agricultural land use and irrigation in the Indian Monsoon Belt. Geophys. Res. Letts, 33, doi:10.1029/2006GL026550.

Douglas, E., A. Beltrán-Przekurat, D. Niyogi, R.A. Pielke, Sr., and C. J. Vörösmarty, 2009: The impact of agricultural intensification and irrigation on land-atmosphere interactions and Indian monsoon precipitation . A mesoscale modeling perspective. Global Planetary Change, 67, 117.128, doi:10.1016/j.gloplacha.2008.12.007.

Lei, M., D. Niyogi, C. Kishtawal, R. Pielke Sr., A. Beltrán-Przekurat, T. Nobis, and S. Vaidya, 2008: Effect of explicit urban land surface representation on the simulation of the 26 July 2005 heavy rain event over Mumbai, India. Atmos. Chem. Phys. Discussions, 8, 8773.8816.

Roy, S.S., R. Mahmood, D. Niyogi, M. Lei, S.A. Foster, K.G. Hubbard, E. Douglas, and R.A. Pielke Sr., 2007: Impacts of the agricultural Green Revolution – induced land use changes on air temperatures in India. J. Geophys. Res. – Special Issue, 112, D21108, doi:10.1029/2007JD008834.

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Filed under Climate Change Forcings & Feedbacks, Research Papers, Uncategorized

E-Mail Interaction With Leonard Ornstein On My Post “Are The IPCC Global Climate Model Multi-Decadal Global Model?”

UPDATE: December 20 2010 pm  Len has sent us the following:

The URL for the “Irrigated Afforestation….” paper is:

The URL for the “Science in the Spectrum of Belief” is


Leonard Ornstein and I have exchanged a set of e-mails related to my post

Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

I have reproduced the e-mail exchange below, with Len’s permission [with some minor editing] .

Date: Thu, 16 Dec 2010 13:58:47 -0500
From: Leonard Ornstein <xxxxxx>
To: Roger A Pielke Sr <xxxxxx>
Subject: Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

Hi Roger:

Setting aside the interpretation of “accurate”, I’d like to remind you of the attached paper that you kindly invited me to discuss on your blog on October 29, 2009;  “How To Quickly Lower Climate Risks, At ‘Tolerable? Costs’“.

I’d argue that the GISS ModelE provided a remarkably ‘believable’ prediction of what roughly might be expected by a rather enormous (and interesting) change in regional forcings.

We are, at present, reexamining “with ‘high expectations'” the performance with the GISS regional model RM3 (0.5º x 0.5º resolution), particularly with respect to the failure of ModelE, at (4º x 5º resolution) to demonstrate significant induced precipitation during the ‘winter half’ of the year .

To expect useful predictions with ‘small’ differences in forcings, is not too reasonable because of the high levels of ‘noise’ in the models, their parametrizations and in the observational data used to ‘tune’ them.

But, with very large differences in regional forcings, the ‘better’ designed GCMs should be expected to be able to tell us surprising things that are quite probable regional consequences.

Len Ornstein

Hi Len

 Thank you for your e-mail. In term of “a remarkably ‘believable’ prediction” this is not a scientifically robust approach. The regional model predictions must be compared against real world data [which is, of course, only possible in the hindcast mode in 2010, but can be accomplished in a truly predictive mode from 2011 and forward].

 However, there are two requirements for demonstrating regional skill. First, the current climatological statistics of societally and environmentally important weather events (e.g. droughts, floods, heat waves, ect) must be skillfully predicted.

Then, the even more difficult task of predicting the changes in these statistics due to the human intervention in the climate system. Large regional effects that are simulated by the GCMs is not a robust test unless corresponding observations can be shown to fit.

On your e-mail, can I post, along with my above reply?

On your paper, one concern I have with the irrigation idea is that while sensible temperature could fall, the moist enthalpy (i.e. heat) would be larger due to the added water vapor.

Best Wishes for the Holidays!


Date: Thu, 16 Dec 2010 21:03:52 -0500
From: Leonard Ornstein <xxxxxx>
To: Roger A Pielke Sr <xxxxxx>

Subject: Re: Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

Hi Roger:
Of course, we agree that the “sensible temperature (does) fall [some 8º over the Sahara -see Figures 3f and 5e] – the moist enthalpy (i.e. heat) (IS) larger due to the added water vapor.  We didn’t claim this as a source of cooling. It’s the enormous sustainable sequestration of CO2 in the new ‘forests on the deserts’ that would ultimately lead to net global cooling; ~ 8 GtC/yr.

With this ‘clarification’, you may post.


Date: Thu, 16 Dec 2010 22:29:55 -0700 (MST)
From: Roger A Pielke Sr <xxxxxx>
To: Leonard Ornstein <xxxxxx>
Subject: Re: Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

Hi Len

 Before I post, please also discuss the albedo change issue. The darker surface will have a higher surface absorption of solar radiation.

Best Regards

Date: Sat, 18 Dec 2010 01:06:20 -0500
From: Leonard Ornstein <xxxxxx>
To: Roger A Pielke Sr <xxxxxx>
Subject: Re: Succinct Summary Of The Scientific Process

Hi Roger:
There is usually nothing distinctive about the low and high tails of an unbiased probability distribution of pertinent observations. “Truth’ and “falsity” are therefore usually symmetrical. It’s not either tail that tests the model  but the entire empirical record to date. For consistent  and ‘natural’ models, the empirical distributions converge rapidly, the distributions are tight and are they stable (as in much of natural science). We ‘like’ to look at these as foundational science  as ‘factual’; but they remain, at best, only the current leading models. However it’s just because of that, that strong forcing of such models either more easily reveals inconsistencies in model construction  or unexpected, but robust, elements of ‘probable’ predictive value. My current prose may yet fail to clearly convey this argument, but that’s part of what it’s about.


On 12/17/10 8:01 PM, Roger A Pielke Sr wrote:
 Hi Len

 Thank you for the article.

 I do not see how any model is scientific if it is not testable (i.e.  shown to be false). Otherwise, it is another type of “proposition”). A  model is just a “hypothesis”.

 On your paper, when you are ready, why not present a guest weblog that  summarizes your paper and provides a link to it. This would be a very good topic to present and discuss further.


 On Fri, 17 Dec 2010, Leonard Ornstein wrote:

 Hi Roger:

Sorry to be such a pest!

But no model can “at least potentially, be shown to be false” any more than it can be shown to be “true” (despite Karl Popper  or anyone else!). Please read my attached draft of  “The Sceptical Scientific Mind-Set in the Spectrum of Belief: It’s about models of  “reality” and the unavoidable incompleteness of evidence, for  “or against” any model.”


Date: Sat, 18 Dec 2010 01:37:27 -0500
From: Leonard Ornstein <xxxxx>
To: Roger A Pielke Sr <xxxxx>
Subject: Re:: Re: Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

Hi Roger:

Attached are typical albedo anomalies. {NOTE from R. Pielke Sr: These figures are reproduced at the end of this post]


Hi Len

 Examples would be useful. However, I remain unconvinced if the resultant albedo (averaged over the region and in time) would be higher than the already high albedo.


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Filed under Climate Change Forcings & Feedbacks, Climate Models, Guest Weblogs

Postdoctoral Opportunity In Southern Africa

One of my close colleagues, Dr. Jimmy Adegoke, is Executive Director of the CSIR Natural Resources and the Environment in Pretoria South Africa. There is an opportunity for outstanding young scientists to further develop their careers in

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Succinct Summary Of The Scientific Process

There is a succinct and accurate description of science in the book

Tattersall, Ian, 2008: The World from Beginnings to 4000 BCE (New Oxford World History). Oxford University Press. 143 pp

The author writes

“Many of us look upon science as a rather absolutist system of belief. We have a vague notion that science strives to “prove” the correctness of this or that idea about nature and that scientists are all of paragons of objectivity in white coats. But the idea that some beliefs are “scientifically proven” is in many ways an oxymoron. In reality, science does not actually set out to provide positive proof of anything. Rather, it is a constantly self-correcting means of understanding the world and the universe around us. To put it in a nutshell, the vital characteristic of any scientific idea is not that it can be proven to be true but that it can, at least potentially, be shown to be false (which is not the case for all kinds of proposition).”

Since the IPCC multi-decadal climate predictions of the coming century that are given to the impacts community and policymakers cannot be shown to be false, this approach is not a proper use of the scientific method.

I have discussed this previously; e.g. see

Hypothesis Testing – A Failure In The 2007 IPCC Reports

Short Circuiting The Scientific Process – A Serious Problem In The Climate Science Community

The excellent summary by Ian Tattersall presents this veiwpoint very clearly.

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Filed under Climate Science Misconceptions

Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

There is an editorial [h/t to Michael Lenaghan!]

Kundzewicz, Z. W. & Stakhiv, E. Z. (2010) Are climate models “ready for prime time” in water resources management applications, or is more research needed? Editorial. Hydrol. Sci. J. 55(7), 1085-1089

which raises the broader question:

Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

The editorial includes the text

“In general, despite the considerable progress achieved, GCMs still cannot reconstruct the important details of the climate at smaller scales (regional to local). They cannot resolve sub-grid processes, e.g. related to topography and land use. Hence, other techniques, such as regional climate models (RCMs), or downscaling methods, have been developed. A typical RCM grid is of the order of 10–50 km, although some climate simulations have used smaller grids, but usually only for a shorter temporal horizon of simulations. Alternatively, statistical downscaling can be used, based on relationships linking large-scale atmospheric variables (predictors) and local/regional climate variables (predictands),
cf. Wilby (2010).

However, it should be understood that RCMs operate under a set of boundary conditions set by whatever GCM is being used. Hence, if the GCM does not do an adequate job of reproducing the climate signal of a particular region, the RCM will simply mimic those inaccuracies and biases, and propagate the uncertainties even further, albeit at a regional scale.
It is not clear how the coupling of a RCM to a flawed GCM can provide more refined insights, any more than can statistical downscaling.”

This is an important issue since even if the global climate models could accurately predict an annual global average of any climate variable [a big IF which is still being debated], if they cannot skillfully predict the spatial and temporal scales that matter in terms of environmental and social impacts (such as water resources), they are of no value. Indeed, as a result of the fine-scale spatial resoluton that regional downscaling can provide, they can mislead policymakers into accepting the predictions as skillful when they are not.

I have discussed this subject in papers and in a variety of weblog posts; e.g. see

Can Regional Vulnerability Be Accurately Assessed By Using Multi-Decadal Global Model Predictions?

where I wrote

“The use of multi-decadal global climate models as the driver of determing hotspots [the most responsive regions to climate change], however, is dependent on these global models being able to skillfully predict regional climate change….As we have reported on the Climate Science weblog, there is no skill in predicting multi-decadal regional climate (see).

Thus, how can these multi-decadal models be used to identify hot spots? These models do not even include all of the first order climate forcings and feedbacks…..

The answer is that they cannot…..Actually “hot spots” are likely to be quite different when the actual vulnerability of regions are assessed using a bottom-up (“place-based”) perspective in which all threats (social as well as environmental) are included.”

The clear answer to the question

Are The IPCC Global Climate Model Multi-Decadal Global Model Predictions Accurate On Regional And Local Spatial Scales?

is NO.  I invite climate science colleagues to e-mail me to present a counter viewpoint to this answer which we will present as a guest post.

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Filed under Climate Models, Q & A on Climate Science

Two American Meterological Society Statements Official

The American Meteorological Society has headlined the two policy statements [which I was fortunate to be able to assist on the committtee that completed them]. The two Statements are

  • AMS Statement: Inadvertent Weather Modification
  • AMS Statement: Planned Weather Modification through Cloud Seeding

    It has taken two years to complete this process.  It does represent the broadening of the AMS to consider that the role of humans in the climate system involves much more than just the effects due to the addition of CO2 and  several other greenhouse gases.

    Excerpts from the first AMS Statement include

    “This section summarizes the current knowledge of the physical processes affecting weather modification as a result of changes in land use, aerosol, and gas emissions.

    a. Aerosol radiative effects

    By partially blocking solar radiation from heating the surface, air pollutants lower surface heating and evaporation rates.  This slows vertical air motions, and hence causes slower dispersal rates of air pollutants, and suppresses formation of convective clouds and precipitation.  Reduced surface evaporation has major implications for the global hydrological cycle and how it responds to the combined forcing of GHGs, land use change, and aerosol pollution.  In addition, surface deposition of dark aerosols accelerates ice-melt rates, hence affecting water resources.  While these conclusions are based on sound physical meteorology, many of these effects are yet to be quantified.

    b. Cloud-mediated effects of aerosol

    Aerosols act mostly as cloud-drop condensation nuclei (CCN), and some of them as ice nuclei (IN), both of which change cloud radiative and precipitation properties in complex ways.  Over oceans, emissions from fossil-fuel-burning ships produce tracks, observed to dramatically influence the extent and persistence of local shallow cloud cover, reducing the amount of solar radiation received at the surface and enhancing the amount reflected back to space.  Aerosols also suppress precipitation from shallow or short-lived clouds (e.g., orographic cap clouds). Their impacts on deep convective clouds are much less certain, but are of potentially great importance.  Recent research suggests that, depending on meteorological conditions, aerosols can either increase or decrease rainfall from such clouds.  In warm moist atmospheres, aerosols often invigorate deep convective clouds, usually resulting in greater electrical activity, stronger damaging winds, and a greater likelihood of flash floods.  Studies indicate that aerosols might also modulate the intensity of tornadoes and hurricanes.

    c. Changes in land use

    One example of significant land use change is the rapid global increase in urbanization and its associated changes in land surface properties and topography that create “urban heat islands” and urban barrier effects that perturb regional air flows, which thus redistributes precipitation, runoff, and flood risk over and around cites. Land-use changes alter surface albedos, as well as surface fluxes of heat, water vapor, and momentum to the atmosphere, and thus modify local and regional atmospheric circulations, which in turn can modify weather. For example, when a forest is removed and replaced by an agricultural field, it can result in a significantly different albedo, especially after a snow storm.  Artificial lakes, and wind and solar farms also change the surface fluxes and albedo. Such changes also occur indirectly through increases in nitrogen deposition and atmospheric CO2, which alter leaf area amounts and thus the portioning of latent and sensible heat fluxes.  Poor agricultural practices that favor wind erosion, such as from summer fallow, overgrazing, and deforestation, as well as from tillage, can produce large quantities of dust that absorb and reflect solar radiation thereby modifying clouds and precipitation processes.”

    “The cumulative changes in surface and atmospheric heat and moisture profiles modify atmospheric circulation and weather patterns on all scales, including synoptic storm tracks, in ways that are just beginning to be explored.  In the aggregate, these changes can affect air quality, ecosystems, and water resources.  The cumulative impacts of inadvertent weather modification may thus result in local or regional-scale climatic alterations superimposed on, and interacting with, natural and GHG-induced climate variability and change. Understanding of inadvertent weather modification, still in its infancy, is thus necessary for understanding the sources, triggers, and response mechanisms of climate change.”

    High-priority research and new technological capabilities are required to improve understanding of the impacts of inadvertent weather modification.  These might include:

    • Further use of satellite remote sensing of land, trace gas, aerosol, cloud, and precipitation properties.
    • Enhanced documentation of emissions of aerosols and their precursors; their chemical evolution; radiative properties; CCN and IN activity; and their transport and deposition.
    • Expanded in situ measurements of aerosol–atmosphere and land–atmosphere interactions over a range of cloud regimes, from fair weather to severe convective storms and to hurricanes.
    • Detailed simulations of these processes at a hierarchy of scales, up to global.

    These research efforts on unintended weather modification should be recognized as addressing parts of the broader question of climate variability and change, which crosses geopolitical boundaries.”

    This Statement [as I have posted on previously; i.e. see] provides wider support for the findings that we reported on in the 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.

    The second Statements implicitly involves geoengineering (although the AMS has a separate statement for that; see my post).  Excerpts from that Statement read

    “Cloud seeding techniques have been developed over nearly 70 years through experimentation and trials. In this statement we focus on the policy issues that pertain to local-scale application of these techniques covering areas from a few to several hundreds of square kilometers. Larger-scale efforts to intentionally modify weather and climate using these or other techniques are discussed in a separate AMS policy statement on geoengineering.”

    “From time to time methods have been proposed for modifying extreme weather phenomena, such as seeding severe thunderstorms with aerosols to diminish tornado intensity, or seeding tropical cyclones to cause changes in their dynamics and steer them away from land and/or diminish their intensity. Some experimentation has taken place in these areas, but current knowledge of these complex weather systems is limited and the physical basis by which seeding might influence their evolution is not well understood. ”

    “Weather modification techniques other than cloud seeding have been used in various areas of the world for short periods of time to achieve goals similar to those of cloud seeding. Much less is known about the effects of these other techniques, and their scientific basis is even further from being demonstrated, either statistically or physically, than it is for cloud seeding. Application of weather modification methods that are not supported by statistically positive results combined with a well-understood physical chain of processes leading to these results, and that can also be replicated by numerical cloud modeling, should be discouraged.”

    The scientific uncertainty (and thus dangers of deliberate intervention in the global climate system – “geoengineering”) indicate that geoengineering is a very poor idea.

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    Filed under Climate Science Reporting

    New Research Paper “Modelling The Chemically Aged And Mixed Aerosols Over The Atlantic Ocean” By Astitha Et Al 2010

    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

    we wrote (bold face added)

    “In addition to greenhouse gas emissions, other first order human climate forcings are important to understanding the future behavior of Earth’s climate. These forcings are spatially heterogeneous and include the effect of aerosols on clouds and associated precipitation [e.g., Rosenfeld et al., 2008], the influence of aerosol deposition (e.g., black carbon (soot) [Flanner et al. 2007] and reactive nitrogen [Galloway et al., 2004]), and the role of changes in land use/land cover [e.g., Takata et al., 2009]. Among their effects is their role in altering atmospheric and ocean circulation features away from what they would be in the natural climate system [NRC, 2005].”

    There is a very important new paper that provides further quantitative documentation of the role of aerosols (including human caused aerosols) within the climate system. It is

    M. Astitha, G. Kallos, C. Spyrou, W. O’Hirok, J. Lelieveld, and H. A. C. Denier van der Gon, 2010: Modelling the chemically aged and mixed aerosols over the Atlantic Ocean. Atmos. Chem. Phys., 10, 1–26, 2010.

    The abstract reads [bold face added]

    “Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size distribution, using chemistry-transport models, satellite data and in situ measurements. We focus on August 2005, a period with intense hurricane and tropical storm activity over the Atlantic Ocean. A mixture of anthropogenic (sulphates, nitrates), natural (desert dust, sea salt) and chemically aged (sulphate and nitrate on dust) aerosols is found entering the hurricane genesis region, most likely interacting with clouds in the area. Results from our modelling study suggest rather small amounts of accumulation mode desert dust, sea salt and chemically aged dust aerosols in this Atlantic Ocean region. Aerosols of smaller size (Aitken mode) are more abundant in the area and in some occasions sulphates of anthropogenic origin and desert dust are of the same magnitude in terms of number concentrations. Typical aerosol number concentrations are derived for the vertical layers near shallow cloud formation regimes, indicating that the aerosol number concentration can reach several thousand particles per cubic centimetre. The vertical distribution of the aerosols shows that the desert dust particles are often transported near the top of the marine cloud layer as they enter into the region where deep convection is initiated. The anthropogenic sulphate aerosol can be transported within a thick layer and enter the cloud deck through multiple ways (from the top, the base of the cloud, and by entrainment). The sodium (sea salt related) aerosol is mostly found below the cloud base. The results of this work may provide insights relevant for studies that consider aerosol influences on cloud processes and storm development in the Central Atlantic region.”

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    Filed under Climate Change Forcings & Feedbacks

    My Comments On An Excellent Weblog Post By Judy Curry

    There is a very thoughtful, must read post by Judy Curry at Climate Etc titled

    Testimony followup: Part II

    I have extracted below a key set of statements from her post [boldface added]

    “The actual shift within the community seems to have occurred in the context of the IPCC process. The entire framing of the IPCC was designed around identifying sufficient evidence so that the human-induced greenhouse warming could be declared unequivocal, and so providing the rationale for developing the political will to implement and enforce carbon stabilization targets in the context of the UNFCCC. National and international science programs were funded to support the IPCC objectives.  Scientists involved in the IPCC advanced their careers, obtained personal publicity, and some gained a seat at the big policy tables.  This career advancement of IPCC scientists was done with the complicity of the professional societies and the institutions that fund science.  Eager for the publicity, high impact journals such as Nature, Science, and PNAS frequently publish sensational but dubious papers that support the climate alarm narrative…..Further, the institutions that support science use the publicity to argue for more funding to support climate research and its impacts. And the broader scientific community inadvertently becomes complicit in all this. When the IPCC consensus is attacked by deniers and the forces of “anti-science,” scientists all join in bemoaning these dark forces fighting a war against science, and support the IPCC against its critics. The media also bought into this, by eliminating balance in favor of the IPCC consensus.”

    Changing the funding priorities is key. We need to reduce reliance on building ever more complex climate models for being the primary source of reducing uncertainties regarding climate change. Climate researchers need to engage with a broader range of expertise in and build strong links to disciplines experienced in complex nonlinear modeling and statistical inference, among others. We need a much better understanding of natural climatic variability.  More research is needed on understanding abrupt climate change and developing a more extensive archive of paleoclimate proxies.  And finally, greater resources need to be provided to accelerating the establishment of definitive climate data records.”

    I have reported examples of the biases that Judy documented with respect to climate assessments and funding on my weblog; e.g.see

    Protecting The IPCC Turf – There Are No Independent Climate Assessments Of The IPCC WG1 Report Funded And Sanctioned By The NSF, NASA Or The NRC – A Repost Of And Comment On A January 13 2009 post

    NSF Decision On Our Request For Reconsideration Of A Rejected NSF Proposal On The Role Of Land Use Change In The Climate System

    My Comments For The InterAcademy Council Review of the IPCC

    Climate Assessment Oligarchy – The IPCC

    See also

    Pielke, R.A. Sr., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“. 88 pp including appendices

    Pielke, R.A. Sr., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy. Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp [see the appendix which documents the exclusion in the 2007 IPCC WG1 report of peer-reviewed papers that differ from what the IPCC perspective].

    I recommend everyone read Judy’s full post.

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    Filed under Climate Science Presentations

    Another Recognized Vegetation Feedback Within The Climate System

    Anthony Watts has alerted us to an important new paper which documents another climate feedback. See his post

    NASA climate model shows plants slow Global Warming by creating a new negative feedback in response to increased CO2.

    The paper is

    Bounoua, L., F. G. Hall, P. J. Sellers, A. Kumar, G. J. Collatz, C. J. Tucker, and M. L. Imhoff (2010), Quantifying the negative feedback of vegetation to greenhouse warming: A modeling approach, Geophys. Res. Lett., 37, L23701, doi:10.1029/2010GL045338.

    The abstract reads

    “Several climate models indicate that in a 2 × CO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation down‐regulation to reduce plant’s photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2 × CO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous simulations with elevated CO2. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6°C. Compared to previous studies, these results imply that long term negative feedback from CO2‐induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration.”

    Excerpts from the conclusions are

    “As an additional feedback to water availability caused by CO2‐induced water use efficiency and changes in climate, we postulate that the excess photosynthetic capacity following down‐regulation of the vegetation physiological activity would stimulate vegetation growth much more than previously simulated. When we include these feedbacks in climate simulations with 2 × CO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff. This results in an additional cooling effect not fully accounted for in previous elevated CO2 climate simulations…….results from this study suggest that long term negative feedbacks from increases in LAI could act to reduce temperature for years following a stabilization of atmospheric CO2 concentration.”

    This study reinforces what we found in our papers; e.g. see

    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.

    Our abstract included the findings

    “Results indicate that the biological effect of enriched CO2, and of land-use change exhibit dominant effects on regional meteorological and biological fields, which were observed for daily to seasonal time scales and grid to regional spatial scales….Model results highlight the importance of including 2 X CO2 biological effects when simulating possible future changes in regional weather.”

    Our other papers on this subject include

    Alpert, P., D. Niyogi, R.A. Pielke Sr., J.L. Eastman, Y.K. Xue, and S. Raman, 2006: Evidence for carbon dioxide and moisture interactions from the leaf cell up to global scales: Perspective on human-caused climate change. Global and Planetary Change, Special Issue, 54, 202-208,

    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.

    Narisma, G.T., A.J. Pitman, J. Eastman, I.G. Watterson, R. Pielke Sr., and A. Beltran-Przekurat, 2003: The role of biospheric feedbacks in the simulation of the impact of historical land cover change on the Australian January climate. Geophys. Res. Letts., 30(22), 2168, doi:10.1029/2003GL018261

    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.

    While the authors of the Bounoua et al paper was not aware of our earlier studies, I am pleased that the important effect of vegetation dynamics on the climate system continues to be better recognized.

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