Monthly Archives: June 2006

The Inaugural AASC Dissertation Award to Christopher A. Davey -Congratulations!

I am pleased to announce that Dr. Christopher A. Davey of the Desert Research Institute in Reno and with the Western Regional Climate Center was awarded the Inaugural Dissertation Medal in Applied Climatology by the American Association of State Climatologists. This recognition by his peers in the climate community is well deserved.

He has been senior author on several important contributions and his paper

Davey, C.A., R.A. Pielke Sr., and K.P. Gallo, 2006: Differences between near-surface equivalent temperature and temperature trends for the eastern United States – Equivalent temperature as an alternative measure of heat content. Global and Planetary Change, accepted,

was specifically selected as evidence of his significant research as part of his Ph.d dissertation. The abstract of the paper is

“There is currently much attention being given to the observed increase in near surface air temperatures during the last century. The proper investigation of heating trends, however, requires that we include surface heat content to monitor this aspect of the climate system. Changes in heat content of the Earth’s climate are not fully described by temperature alone. Moist enthalpy or, alternatively, equivalent temperature, is more sensitive to surface vegetation properties than is air temperature and therefore more accurately depicts surface heating trends. The microclimates evident at many surface observation sites highlight the influence of land surface characteristics on local surface heating trends. Temperature and equivalent temperature trend differences from 1982- 1997 are examined for surface sites in the Eastern U.S. Overall trend differences at the surface indicate equivalent temperature trends are relatively warmer than temperature trends in the Eastern U.S. Seasonally, equivalent temperature trends are relatively warmer than temperature trends in winter and are relatively cooler in the fall. These patterns, however, vary widely from site to site, so local microclimate is very important.

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On Professor Bill Gray and the Debate on Climate Change

There has been considerable discussion regarding Professor William Gray of Colorado State University regarding his views on climate change, and hurricane trends, as affected by human activity, in particular. The news article in Westwood on June 29th provides a summary of the bitterness that has developed among the individuals who are performing research in this area of science.

I have known Professor Gray for over 25 years, both by reputation before I joined the faculty at Colorado State University (CSU), and during my tenure on the faculty at CSU. He truly is an outstanding investigator in tropical cyclones who has used innovative ideas to utilize observational data in order to better understand these storms. He has published seminal papers in this subject, such as (one example per decade)

Global View of the Origin of Tropical Disturbances and Storms, 1968 Monthly Weather Review by William M. Gray.

Diurnal Variation of Deep Cumulus Convection, 1977 Monthly Weather Review by William M. Gray and Robert W. Jacobson Jr.

Atlantic Seasonal Hurricane Frequency. Part II: Forecasting its Variability, 1984 Monthly Weather Review by William M. Gray

Downward trends in the frequency of intense Atlantic hurricanes during the past five decades, 1996 Geophysical Research Letters by Christopher W. Landsea, Nicholls, Neville, William M. Gray, and Lixion A. Avila.

Trends in Global Tropical Cyclone Activity over the Past Twenty Years (1986-2005)”, 2006 by Phil Klotzbach (who is supervised and directed in his PhD dissertation research by Professor Gray).

For professional colleagues to make statements such as

”’Gray has “brain fossilization,’ Curry told a Wall Street Journal reporter a few weeks ago, and ‘nobody except a few groupies wants to hear what he has to say'”,

is not only completely wrong but is a personal attack which should not have any place in climate science discussions. Judy should apologize to Bill for this statement.

Thus, while I feel that Professor Gray is often blunt and nondiplomatic in his statements, the scientific issues that he raises should be scrutinized objectively, and not dismissed since they do not conform to one’s perspectives on climate variability and change. He has the national and international professional credentials and stature in climate science such that his views are critically important as we debate the science. I have urged him to publish his newer research, and, hopefully, as a result of the furor over the issue of long term hurricane trends and the role of humans activity on their number, intensity, track and societal impact, this will encourage him to complete these much needed peer reviewed articles.

I look forward to their important contributions to the scientific debate when they appear!

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Climate Science?

There were several news releases on June 26th that warrant comment. Jeremy Lovell of Reuters wrote an article entitled “US has duty to lead on global warming”. The news release contained the text,

“Addressing a meeting of international climate scientists and policymakers, John Houghton, a former senior member of the Intergovernmental Panel on Climate Change, said urgent action was imperative.

‘If only the U.S. administration could flip from denial to acceptance it could save the world,’ he said. ‘If the Americans continue to do nothing then we have a big problem — therefore they must do something.'”

What could the U.S. administration do to “save the world”? Where is the climate science in this quote?

A second article, released by MSNBC, was entitled “Justices to hear global warming case 12 states want Bush administration to regulate carbon dioxide emissions” which included the text,

“The Supreme Court agreed Monday to consider whether the Bush administration must regulate carbon dioxide to combat global warming, setting up what could be one of the court’s most important decisions on the environment.

The dozen states, a number of cities and various environmental groups asked the court to take up the case after a divided lower court ruled against them.

They argue that the Environmental Protection Agency is obligated to limit carbon dioxide emissions from motor vehicles under the federal Clean Air Act because as the primary ‘greenhouse’ gas causing a warming of the earth, carbon dioxide is a pollutant.”

If the legal claim actually states that CO2 is the “primary ‘greenhouse’ gas causing a warming of the earth”, this claim is in error. An increase in water vapor, concurrent with the increase in CO2 and other warming climate forcings (these other climate forcings are summarized on the Climate Science weblog; see), is the primary greenhouse gas!

These two articles have flaws in their representation of climate science.

A third article in the June 24th-June 30th Economist entitled “Bolton v Gore” (subscription required) is a valuable report on climate, and environmental, science. The article includes the text,

“…….over the weekend, Mr Bolton sat down with UN diplomats from seven other countries, including China and India but no Europeans, to rank 40 ways of tackling ten global crises. The problems addressed were climate change, communicable diseases, war, education, financial instability, governance, malnutrition, migration, clean water and trade barriers.

Given a notional $50 billion, how would the ambassadors spend it to make the world a better place? Their conclusions were strikingly similar to the Copenhagen Consensus. After hearing presentations from experts on each problem, they drew up a list of priorities. The top four were basic health care, better water and sanitation, more schools and better nutrition for children. Averting climate change came last.

The ambassadors thought it wiser to spend money on things they knew would work. Promoting breast-feeding, for example, costs very little and is proven to save lives. It also helps infants grow up stronger and more intelligent, which means they will earn more as adults. Vitamin A supplements cost as little as $1, save lives and stop people from going blind. And so on. ”

This report parallels the “vulnerability” concept which has been emphasized on this weblog (see). I also asked a similar question on how funds should be spent in environmental issues in one of my powerpoint presentations (see slide 49 ). It is this type of question that needs to be posed if we are to move forward in effective environmental (including climate response) policy.

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Climate Summaries for 2005 Published

The publication “The State Climatologist 2005 edition” is now available. It contains the standard NCDC perspective, but also has a valuable collection of summaries from Regional and State Climate Officies.

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The Weather Where You Live

David A. Robinson, State Climatologist of New Jersey has provided a very valuable summary of publications on the weather for a number of states and regions in the United States (and one for Canada). He refers to this summary as “The Weather Where You Live”. It is a very useful resource of local climate information. If you know of other publications which he does not have listed, I recommend that you send the titles to him, as he requested,

“Should you know of any other appropriate publications, it would be greatly appreciated if you would contact me with the reference ( I will continue to update the list as new references arrive.”

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Lags in the Climate System

The statement is often made that (e.g. see; Comment #3)

“Because of lags in the climate system, the climate of the next few decades has already been determined by prior emissions. Emissions reductions currently being discussed will therefore have an effect primarily on the climate in the 2nd half of the 21st century.”

This perspective is used to conclude that the radiative effect of anthropogenic CO2 is a particularly pernicious influence on the environment, which is much greater then due any of the other climate forcings.

However, this view, in the context of climate science, fails to recognize that a variety of diverse climate forcings have very significant long term influences on the climate.

The reason for the focus on the radiative effect of added CO2 is associated with the emphasis of climate assessments on the atmospheric portion of the climate system. However, as clearly described in the 2005 National Research Council Report , the climate system also includes the oceans, land, and cryosphere, in addition to the atmosphere.

The claim that aerosols could be eliminated as a climate concern in the climate system in just a few weeks (through atmospheric cleansing if their emssion is halted), fails to recognize that the aerosols are just being transfered to a different component of the climate system, and their effects can last for decades and even longer!

Three examples of long term climate forcings, beyond the radiative forcing of anthropogenic caronf dioxide inputs, include:

nitogren deposition (e.g. see )

land use/land cover change (e.g. see )

black carbon deposition (e.g. see )

Each of these climate forcings persist with long term effects on all aspects of climate including weather patterns. The nearly exclusive focus on the climate forcing of the atmospheric component of the climate system (i.e. the radiative forcing of CO2) with respect to long term lags is scientifically flawed.

This also means that we can not treat the climate system different from weather in that both are sensitive to initial conditions (e.g. see

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

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Further evidence regarding role of land use on precipitation: urbanization as a missing component in current climate models

A new paper highlighting the importance of the urban land surface representation in numerical weather prediction (NWP) models has been accepted by the Journal of Geophysical Research. For this study the authors coupled an explicit urban canopy energy balance model with a photosynthesis based land surface model. These land surface models were then in turn coupled to a high resolution NWP model. This modeling system was used to simulate a mesoscale convection and precipitation event that was observed in the vicinity of Oklahoma City during a field experiment. The authors conclude that considering urban land surface explicitly improved the ability of the model to simulate precipitation and other model features. Without the explicit consideration of the urban model, the coupled system underpredicted rainfall, and had errors in the the location of convection as well as in accurately simulating the intensity of the temperature differences due to the urban heat island. Current NWP models- including GCMs (and also, therefore, climate models) do not explicitly consider urban areas and could have large errors due to this neglect in and around regions which have urban concentrations.

Dev Niyogi, Teddy Holt, Sharon Zhong, Patrick C. Pyle, Jeffery Basara, Urban and Land Surface Effects on the 30 July 2003 MCS Event Observed in the Southern Great Plains, Journal of Geophysical Research, accepted.

The abstract reads,

” The urban canopy of excess heat, water vapor, and roughness can affect the evolution of weather systems, as can land-vegetative processes. High-resolution simulations were conducted using the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS(r) ) to investigate the impact of urban and land-vegetation processes on the prediction of the mesoscale convective system (MCS) observed on 30 July 2003 in the vicinity of Oklahoma City (OKC), Oklahoma. The control COAMPS model (hereafter CONTROL) used the Noah land surface model (LSM) initialized with the Eta Data Assimilation System and incorporates an Urban Canopy Parameterization (UCP). Experiments assessed the impact of land-vegetative processes by: (1) adding a canopy-resistance scheme including photosynthesis (GEM) to the Noah LSM, and (2) replacing the UCP with a simpler urban surface characterization of roughness, albedo, and moisture availability (NOUCP).

The three sets of simulations showed different behaviors for the storm event. The CONTROL simulation propagated two storm cells through the OKC urban region. The NOUCP also resulted in two cells, although the convective intensity was weaker. The GEM simulation produced one storm cell west of the downtown region, whose intensity and timing were closer to the observed. To understand the relative roles of the urban and vegetation interaction processes, a factor-separation experiment was performed. The urban model improved the ability to represent the MCS, and the enhanced representation of vegetation further improved the model performance. The enhanced performance may be attributed to better representation of the urban-rural heterogeneities and improved simulation of the moisture fluxes and upstream inflow boundaries.

This study, although focused on numerical weather prediction, provides another example of the important role of the land surface as a climate forcing.

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Comment on the NRC Report “Surface Temperature Reconstructions for the Last 2000 Years”

The Report “Surface Temperature Reconstructions for the Last 2000 Years” has appeared. This Report discusses the IPCC “hockey stick” plot of the multi-century global average surface temperature trends.

When I first saw this plot several years ago, I assumed it would be quickly shown that pasting togther of proxy data with the instrument data for the last few decades is scientifically flawed. These two approaches represent two distinctly different procedures to assess surface temperature trends. However, this hockey stick figure has become an icon for communicating global warming (and climate change, in general) to the public and policymakers.

In the Report, I fail to see an assessment of the following questions:

1. What is the uncertainty associated with the diagnosis of a global average surface temperature trend by pasting the instrument record onto the end of the proxy record? How does proxy data in the last few decades correspond to the measured surface air temperature trends AT THE SAME LOCATIONS?

2. Why is it assumed that “The Earth warmed by roughly 0.6 degrees….during the 20th century..” when we have documented biases in the peer reviewed literature in the assessment of trends in the land surface temperature data (e.g. see “Should light wind and windy nights have the same temperature trends at individual levels even if the boundary layer averaged heat content change is the same?”; “Assessing ‘Global Warming’ with Surface Heat Content”)? In a national assessment, why was such peer reviewed literature ignored?

Ignoring these science questions provides the perspective that the Report is intended to promote a particular perspective on climate science, rather than providing a balanced presentation on the issues. Indeed, the statement in Boston Globe that,

“Our conclusion is that this recent period of warming is likely the warmest in a (millennium),’’ said John Wallace, one of the 12 members on the panel and professor of atmospheric science at the University of Washington”,

clearly shows such a biased view. The Report is a disappointment in not adequately addressing the accuracy of the global surface temperature trend data. Since its accuracy is at the foundation of the entire Report, the absence of such an evaluation very substantially weakens the value of the Report in climate science.

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Impact of Tropical Deforestation on Climate

The Aspen Global Change Institute (AGI) has had excellent meetings in past. In the venue that they used when I attended, a rich diversity of viewpoints on climate science were presented, and subsequently summarized in reports. In this weblog, I want to communicate the main points of a summary of the presentation by Karen L. O’Brien who attended a 1997 meeting on “Elements of Change 1997: Scaling from Site-Specific Observations to Global Model Grids“.

The report on her work entitled “Scales of Change: The Climatic Impacts of Tropical Deforestation in Chiapas, Mexico” is relevant to all areas of the humid tropics. The report concludes that

“General circulation models coupled with atmosphere-biosphere models provide increasing evidence that deforestation can significantly influence the climate at a number of scales.”

Here are several of the bullet summaries based on her research, as extracted from the AGI Report:

1. “In scaling up to higher levels of analysis, emergent properties may appear as a result of synergistic interactions taking place at higher levels of system integration, such as the regional or global scale.”

2. “Tropical deforestation usually results in a mosaic pattern of land cover, and there is evidence that the atmospheric response to a heterogeneous land surface is nonlinear.”

3. “There is a growing recognition that the simulated impacts of deforestation on the climate are regionally specific, in large part due to the different scales of the deforested areas.”

4. “O’Brien’s local scale analysis shows a strong tendency for maximum daily temperatures to decrease at climate stations exhibiting high deforestation, particularly to the northeast of the station.”

5. “There is no clear-cut distinction between “forested” and “deforested” stations. Instead, deforestation appears as a continuum among stations.”

6. “There is a tendency for minimum temperatures to increase at some of the stations, but the majority of stations show no change.”

7. “Annual precipitation totals are highly variable with no clear trends, contrary to a widespread perception that rainfall has decreased in the Selva Lacandona.”

8. “The amount of deforestation in the full circle surrounding the climate stations seems to be less important than the location of the clearings. ”

9. “These results do not contradict conclusions based on global modeling studies, but they do indicate that the issue of local-scale changes is more complex than the models suggest.”

10. “Environmental change research demands an integrated approach that recognizes the complexity of scale, as well as the importance of analyzing data at a number of scales.”

I also recommend her excellent book,
“Sacrificing the Forest : Environmental & Social Struggle in Chiapas”,

which clearly exemplifies why the vulnerability paradigm is such a powerful assessment tool for policymakers.

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Further Evidence of the Biases in Surface Temperature Measurements At Poorly Sited Locations

An important new paper has appeared which further documents major concerns regarding the use of surface air temperature data to assess long term temperature trends. The June 30, 2006 International Journal of Climatology paper by by Rezaul Mahmood, Stuart A. Foster and David Logan is entitled “The Geoprofile metadata, exposure of instruments, and measurement bias in climatic record revisited“(subscription required).

The abstract reads,

“Station metadata plays a critical role in the accurate assessment of climate data and eventually of climatic change, climate variability, and climate prediction. However, current procedures of metadata collection are insufficient for these purposes. This paper introduces the GeoProfile as a model for documenting and visualizing enhanced spatial metadata. In addition to traditional metadata archiving, GeoProfiles integrate meso-scale topography, slope, aspect, and land-use data from the vicinity of climate observing stations ( main.html). We describe how GeoProfiles are created using Geographical Information Systems (GIS) and demonstrate how they may be used to help identify measurement bias in climate observations due to undesired instrument exposures and the subsequent forcings of micro- and meso-environments. A study involving 12 COOP and US Historical Climate Network (USHCN) stations finds that undesirable instrument exposures associated with both anthropogenic and natural influences resulted in biased measurement of temperature. Differences in average monthly maximum and minimum temperatures between proximate
stations are as large as 1.6 and 3.8 °C, respectively. In addition, it is found that the difference in average extreme monthly minimum temperatures can be as high as 3.6 °C between nearby stations, largely owing to the differences in instrument exposures. Likewise, the difference in monthly extreme maximum temperatures between neighboring stations are as large as 2.4 °C. This investigation finds similar differences in the diurnal temperature range (DTR). GeoProfiles helped us to identify meso-scale forcing, e.g. instruments on a south-facing slope and topography, in addition to forcing of micro-scale sitting.”

Among the conclusions in the text are the statements that,

“In an ideal setting, a well sited station results in recorded temperature values that are free of bias and
representative of the broader region. However, the presence of bias in temperature observations has long been recognized. While troublesome, it is still possible to analyze climate variability and assess climate change if the site and locality of a station remain unchanged, and the bias is stationary over time. Collectively, our analyses of temperature data from 12 COOP stations (including two that are part of the USHCN) show complex patterns of pairwise temperature variability and suggest the influence of multiple sources of bias that are nonstationary over different timescales.

Evidence of bias can be found in temperature records from both urban and rural sites. All of the urban based stations in this study are located in towns and cities ranging in population from just over 2000 to nearly 20 000. Certainly, the small scale of urbanization limits the traditional UHI bias. However, research in urban micrometeorology (Arnfield, 2003) identifying the impacts of diverse surfaces on energy budgets, energy exchanges, and small-scale advection suggests that even a limited urbanization is relevant when examining the potential impacts of the site and locality characteristics of instrument exposures on temperature observations. While rural settings are generally considered to provide superior settings for climate observations, our research reveals that the micro-environments of rural stations are often similar to those of urban stations. Specifically, they are often characterized by the presence of paved surfaces and brick and block buildings in close proximity to instrument installations. In some cases, superior sites are available nearby.”

“Collectively, these empirical results raise questions about the interpretation of climatological time series associated with arbitrarily selected stations from the NWS COOP network, including stations that are part of the USHCN.”

This new peer reviewed paper provides even more evidence that the claims in Chapter 3 of the CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“ of a robust multi-decadal surface temperature trend assessment is erroneous.

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