Monthly Archives: July 2007

New Research Paper On Landscape History In the Eastern Half Of The United States

A truly exceptional research paper is in press for the Journal of Geophysical Research. It is

Steyaert, L. T., and R. G. Knox (2007), Reconstructed Historical Land Cover and Biophysical Parameters for Studies of Land-Atmosphere Interactions within the Eastern United States, J. Geophys. Res., doi:10.1029/2006JD008277, in press. [those of you with AGU subscriptions can view the entire paper (see)].

The abstract reads,

“Over the past 350 years, the eastern half of the United States experienced extensive land cover changes. These began with land clearing in the 1600s, continued with wide-spread deforestation, wetland drainage, and intensive land use by 1920, and then evolved to the present-day landscape of forest regrowth, intensive agriculture, urban expansion, and landscape fragmentation. Such changes alter biophysical properties that are key determinants of land-atmosphere interactions (water, energy, and carbon exchanges). To understand the potential implications of these land use transformations, we developed and analyzed 20-km land cover and biophysical parameter datasets for the eastern United States at 1650, 1850, 1920, and 1992 time-slices. Our approach combined potential vegetation, county-level census data, soils data, resource statistics, a Landsat-derived land cover classification, and published historical information on land cover and land use. We reconstructed land use intensity maps for each time-slice and characterized the land cover condition. We combined these land use data with a mutually-consistent set of biophysical parameter classes, to characterize the historical diversity and distribution of land surface properties. Time-series maps of land surface albedo, leaf area index, a deciduousness index, canopy height, surface roughness, and potential saturated soils in 1650, 1850, 1920, and 1992 illustrate the profound effects of land use change on biophysical properties of the land surface. Although much of the eastern forest has returned, the average biophysical parameters for recent landscapes remain markedly different from those of earlier periods. Understanding the consequences of these historical changes will require land-atmosphere interactions modeling experiments.”

This study is the most in-depth analysis ever completed on the transformation of the landscape of the eastern half of the United States, and is a truly seminal paper on this subject. The study also presents the landscape variables in a form that can be directly used within climate models. We are in the process of completing a paper which uses this information;

Strack, J., R.A. Pielke Sr and L. T. Steyaert, 2007: Sensitivity of near-surface temperatures and precipitation in the eastern United States to historical land cover changes since European settlement. Water Resources Res., Special Issue on Impacts of Land-Use Change, In Final preparation

which will be posted soon.

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Powerpoint Presentations From The 2007 Pittsburgh Tripartite Symposium — Realities And Challenges Of Global Warming/Global Dimming

I was invited by Manny Miller (thanks Manny!) who was the coordinator to an excellent set of presentation at the April 23, 2007 Tripartite Symposium — Realities And Challenges Of Global Warming/Global Dimming held in Pittsburgh, Pennslyvania. The meeting was sponsored by the Society for Analytical Chemists of Pittsburgh ( ), Spectroscopy Society of Pittsburgh ( and the American Chemical Society – Pgh Section (

The presentations were:

Dr. M. Granger Morgan-Carnegie Mellon Univ, Why Climate is Changing and What We Can Do About It?

Dr. Beate Liepert – Lamont-Doherty Earth Observatory, The Dilemma of Anthropogenic Impact on Climate: Global Dimming and Global Warming

Dr. Roger A. Pielke Sr.-Univ. of Colorado, The Human Impact on the Weather and Climate

Mr. John Quigley-PA DCNR, Director of Legislation and Strategic Initiatives,Pennsylvania Perspectives, Federal Uncertainty

Those who read Climate Science, will of course, be aware of the perspective that I presented at the meeting. However, the other three talks provide important insight by others, including the emphasis on CO2 as the dominate environmental issue of the coming decades. Climate Science disagrees with this assessment, but recommends readers review the powerpoint talks to learn what is being proposed. For example, Mr. Quigley states that

“Global warming (is) the single biggest long-term threat to PA’s (Pennslyvania’s) existing natural heritage”.

He further discusses Pennsylvania’s significant role in this threat as a result of CO2 emissions from the combustion of the coal which is found in large quantities in the state. He presents a review of what Governor Rendell has proposed to address this issue. It is a candid and informative presentation of where the politics are taking the climate change issue.

Dr. Morgan presented an effective summary of CO2 sequestration and direct air capture technologies. He reported that there are large costs with the implementation of these technologies. He states unequivocally that “there is no uncertainty that CO2 and other greenhouse gases…are warming the planet and changing the climate”, and that “talk about uncertainty about these issues is largely the result of intentional obfurscation by those with short-term economic interests”. Over the coming decades, he has concluded that there will have to be “enormous changes in the nature and operation of the global energy systems.” Dr. Morgan is a Member of the EPA Science Advisory Board so his views have enormous influence.

The third talk by Dr. Beate Liepert was on the role of aerosols in the climate system. A paper on this subject in which she is a co-author has already been discussed on Climate Science (see);

Rosanne D’Arrigo, Rob Wilson, Beate Liepert and Paolo Cherubini, 2007: On the ‘Divergence Problem’ in Northern Forests: A Review of the Tree-Ring Evidence and Possible Causes. Journal of Global and Planetary Change In press.

She states that “by reducing air pollution, we commit up to -0.8degrees C of extra warming.”

These talks, by otherwise outstanding experts within their specific fields, document that the focus on the role of humans within the climate system, unfortunately continues to ignore assessment reports such as

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.

but rather focuses on CO2 has the dominate culprit in causing climate change. The presentations also emphasize, in terms of the remedies proposed, that the issue is energy policy not climate policy.

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Comments On The Second Web Posting By Kevin Trenberth on “Climate Feedback – The Climate Change Blog”

Kevin Trenberth has followed up his weblog on the Nature site Climate Feedback – The Climate Change Blog entitled “Predictions of climate” with a weblog on the subject of climate prediction. This new posting is entitled

Global Warming and Forecasts of Climate Change.

Unfortunately, this new post lacks the candor that is in the original Nature weblog by Kevin Trenberth on this subject (as discussed on Climate Science ; see).

The current weblog makes several misleading statements with respect to the ability to “project” climate change with the multi-decadal global climate models.

First, Trenberth writes,

“In particular there is clear evidence (“warming is unequivocalâ€?) that climate is changing in ways consistent with the climate forcings. Also, the projections are for all aspects of climate, not just global mean temperature.”

This obviously contradicts his statement in his first Nature weblog where he writes

“However, the science is not done because we do not have reliable or regional predictions of climate.”

The model results cannot be “consistent” if they are not reliable and are also not regional in scale!

Second, he writes,

“The same atmospheric models are the atmospheric component of climate models and they are well tested and evaluated, although in climate models lower resolution is used.”

This is true (except the weather models typically do not include atmospheric gaseous and aerosol chemistry which is required in a multi-decadal global climate model). However, as he writes in his first weblog,

“None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond. The Atlantic Multidecadal Oscillation, that may depend on the thermohaline circulation and thus ocean currents in the Atlantic, is not set up to match today’s state, but it is a critical component of the Atlantic hurricanes and it undoubtedly affects forecasts for the next decade from Brazil to Europe. Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized.”

His own words present a very different perspective than given on his new weblog. The atmospheric models may be the same, but the other components of the climate model (ocean, land, cryosphere) are poorly represented!

Third, he writes,

“The authors should recognize that IPCC does not make forecasts but rather makes projections to guide policy and decision makers.”

This is disingenuous to suggest to readers that a forecast and a projection are any different; see

Pielke Sr., R.A., 2002: Overlooked issues in the U.S. National Climate and IPCC assessments. Climatic Change, 52, 1-11

He continues by seeking to separate a forecast from a projection because with a projection

“If those changes are considered undesirable, it can create efforts to change that outcome.”

This is obviously true of forecasts too (weather modification, for example, could change a forecast for rain, but the term projection is never used in this context). The term “projectionâ€? is only introduced, rather than forecasts, to obscure that the multi-decadal global models do not have predictive skill!

It should be clear in his new Nature weblog that, unfortunately, his candid comments in this earlier weblog resulted in negative feedback from his colleagues such that he felt compelled to follow up with a poor summary of climate forecasting. This is unfortunate, as his original weblog was a bridge that can be used to advance climate science.

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New Paper On The Biogeochemical Forcing of Elevated CO2

Thanks to Sallie Sprague for alerting me (through an Long Term Ecological Research – LTER project I am on) to an interesting new paper that has been published in the April 2007 issue of New Phytologist.

The article is

William J. Parton, Jack A. Morgan, Guiming Wang, Stephen Del Grosso
Projected ecosystem impact of the Prairie Heating and CO2 Enrichment experiment New Phytologist (OnlineEarly Articles). doi:10.1111/j.1469-8137.2007.02052.x

The abstract reads

“The Prairie Heating and CO2 Enrichment (PHACE) experiment has been initiated at a site in southern Wyoming (USA) to simulate the impact of warming and elevated atmospheric CO2 on ecosystem dynamics for semiarid grassland ecosystems.

The DAYCENT ecosystem model was parameterized to simulate the impact of elevated CO2 at the open-top chamber (OTC) experiment in north-eastern Colorado (1996–2001), and was also used to simulate the projected ecosystem impact of the PHACE experiments during the next 10 yr.

Model results suggest that soil water content, plant production, soil respiration, and nutrient mineralization will increase for the high-CO2 treatment. Soil water content will decrease for all years, while nitrogen mineralization, soil respiration, and plant production will both decrease and increase under warming depending on yearly differences in water stress. Net primary production (NPP) will be greatest under combined warming and elevated CO2 during wet years.”

Model results are consistent with empirical field data suggesting that water and
nitrogen will be critical drivers of the semiarid grassland response to global change.”

This paper demonstrates that the effect of climate variability and change on the grassland must consider much more than the global average surface temperature, and even the local temperature. The paper also emphasizes the need to consider CO2’s biogeochmical climate forcing, as well as its radiative forcing. The need for better understanding of this complexity was emphasized in the 2005 National Research Council Report “Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties” which has been discussed many times on Climate Science.

The news release on this paper, however, inserts the customary attribution to “global warming”. No where in the Parton et al paper is this term even used! The paper reports on the effect of perturbations of different environmental stressors on the grassland including local air temperature increases, but it does not (and cannot) relate directly to global average climate system heat changes (i.e. “global warming”).

The news release reads as follows (and except for the alluding to “global warming”) is a good report.

“Global warming will have mixed effects on eastern Colorado’s grasslands April 23, 2007

New research results from Colorado State University suggest that the effects of rising atmospheric concentrations of carbon dioxide and global warming will lead to an increase in grass production and a decline in forage quality for grasslands of eastern Colorado and Wyoming.

Study results suggest that both elevated CO2 and warming will increase grass production but the quality of the vegetation will decrease due to lower nitrogen concentration in the forage. William Parton, researcher from Colorado State’s Natural Resource Ecology Laboratory, or NREL, and researcher Jack Morgan from the U.S. Department of Agriculture’s Agricultural Research Service, USDA ARS, studied the effects of warming, increased CO2 levels and the combination of both factors on eastern Colorado grasslands to predict how global warming will affect these ecosystems.

Warming can have both positive and negative impacts on plant production

Results revealed that elevated atmospheric CO2 levels always increase grass growth; however, warming can have both positive and negative impacts on plant production.

‘The potential impact of elevated CO2 levels on Colorado and Wyoming grasslands is mixed since grass production will likely increase while digestibility of forage and cattle weight gains will likely decrease,’ Parton said. ‘Increased air temperatures will have a mixed impact with plant production increasing in wet years and decreasing in dry years.’

These predictions are based on results from an ecosystem model developed using data from locally observed climatic change experiments that will continue during the next five to 10 years.

Experiments combined with ecosystem models

In this experiment, Colorado State and ARS scientists were able to use empirical knowledge from relatively short-term experiments combined with ecosystem models to predict long-term ecosystem responses to the effects of global warming. The scientists used results from a five-year-long CO2 enrichment experiment conducted in northern Colorado to test CO2 impacts in the Daycent ecosystem model. They also used field data from the experiment site, Prairie Heating and CO2 Enrichment or PHACE, located in southern Wyoming that will continue for the next five to 10 years.

‘One of our biggest challenges is how to interpret relatively short-term experiments and predict the long-term global warming consequences on grasslands,’ Morgan said. ‘By taking the results from our field experiments and applying computer models tested using the observed field data, we are able to extrapolate beyond our short-term experiments into the future.’

Critical matter for livestock and native prairie animals

The scientists observed that doubling CO2 levels caused strong and consistent increases in grass growth which was due to improved water-use efficiency. Under the elevated CO2 levels, it was also found that plant nitrogen content was declining in native grasslands. This is a critical matter for livestock and for native animals that have grazed these prairies for thousands of years. Increased CO2 dilutes nitrogen concentration in grazing vegetation. Animals require sufficient forage protein nitrogen to sustain normal weight gains.”

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The GLORIA Program – Monitoring High Altitude Vegetation

Michael Gottfried alerted me to a very important climate monitoring program in which high altitude vegeation is monitored for its long term changes (such as movement of plant species up or down slope. This type of monitoring complements the phenology monitoring that has been discussed on Climate Science (see).

The program is called GLORIA for Global Observation Reesearch Initiative in Alpine Environments. The purpose of GLORIA

“is to establish and maintain a world-wide long-term observation network in alpine environments. Vegetation and temperature data collected at the GLORIA sites will be used for discerning trends in species diversity and temperature. The data will be used to assess and predict losses in biodiversity and other threats to these fragile alpine ecosystems which are under accelerating climate change pressures.”

Apparently this network was justified to funders by the narrow view that that climate change is accelertating from well-mixed greenhouse gases. Nonetheless, it will be an important source of climate information. As we showed in our paper

Stohlgren, T.J., T.N. Chase, R.A. Pielke, T.G.F. Kittel, and J. Baron, 1998: Evidence that local land use practices influence regional climate and vegetation patterns in adjacent natural areas. Global Change Biology, 4, 495-504,

higher altitude vegetation can change in response to a variety of climate forcings (as well as from invasive plants; see).

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Article On The Documentation Of Uncertainties And Biases Associated With Surface Temperature Measurement Sites For Climate Change Assessment” Has Been Published

Pielke Sr., R.A. J. Nielsen-Gammon, C. Davey, J. Angel, O. Bliss, M. Cai, N. Doesken, S. Fall, D. Niyogi, K. Gallo, R. Hale, K.G. Hubbard, X. Lin, H. Li, and S. Raman, 2007: Documentation of uncertainties and biases associated with surface temperature measurement sites for climate change assessment. Bull. Amer. Meteor. Soc., 913-928.

The full paper is available directly from the American Meteorological Society’s Open Access Content source.

The abstract reads,

“The objective of this research is to determine whether poorly sited long-term surface temperature monitoring sites have been adjusted in order to provide spatially representative independent data for use in regional and global surface temperature analyses. We present detailed analyses that demonstrate the lack of independence of the poorly sited data when they are adjusted using the homogenization procedures employed in past studies, as well as discuss the uncertainties associated with undocumented station moves. We use simulation and mathematics to determine the effect of trend on station adjustments and the associated effect of trend in the reference series on the trend of the adjusted station. We also compare data before and after adjustment to the reanalysis data, and we discuss the effect of land use changes on the uncertainty of measurement.

A major conclusion of our analysis is that there are large uncertainties associated with the surface temperature trends from the poorly sited stations. Moreover, rather than providing additional independent information, the use of the data from poorly sited stations provides a false sense of confidence in the robustness of the surface temperature trend assessments.”

This paper shows why the websites that are discussing the siting of the surface temperature trend measurements are so important (Climate Audit and The poorly sited locations add no significant value in the quantitification of multi-decadal near-surface air temperature trends.

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Comment On Why Climate Science Is Presenting Evidence Of Glacier Advance or Near-Stationary Positions In Some Areas

The question has been raised as to why Climate Science is seeking evidence for regions without glacier retreat. It has already been mentioned that the impression that glaciers are retreating almost everywhere worldwide has been expressed in media reports (e.g. see). This web posting provides a clear reason why the summary of papers and other evidence on glacier retreat is needed, since the 2007 IPCC chapter on this subject (Chapter 4) does not completely report on this subject.

The material on Wikipedia entitled “Retreat of glaciers since 1850” makes it clear why this documentation is needed. The Wikipedia article reads,

“The retreat of glaciers since 1850, worldwide and rapid, affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and in the longer term, the level of the oceans. Studied by glaciologists, the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of anthropogenic (human-caused) global warming. Mid-latitude mountain ranges such as the Himalayas, Alps, Rocky Mountains, Cascade Range, and the southern Andes, as well as isolated tropical summits such as Mount Kilimanjaro in Africa, are showing some of the largest proportionate glacial loss.

The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cool temperatures compared to the present. Subsequently, until about 1940 glaciers around the world retreated as the climate warmed. Glacial retreat slowed and even reversed, in many cases, between 1950 and 1980 as a slight global cooling occurred. However, since 1980 a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous, so much so that many glaciers have disappeared and the existence of a great number of the remaining glaciers of the world is threatened. In locations such as the Andes of South America and Himalayas in Asia, the demise of glaciers in these regions will have potential impact on water supplies. The retreat of mountain glaciers, notably in western North America, Asia, the Alps, Indonesia and Africa, and tropical and subtropical regions of South America, has been used to provide qualitative evidence for the rise in global temperatures since the late 19th century…The recent substantial retreat and an acceleration of the rate of retreat since 1995 of a number of key outlet glaciers of the Greenland and West Antarctic ice sheets, may foreshadow a rise in sea level, having a potentially dramatic effect on coastal regions worldwide.”

The statement that the retreat since 1850 is rapid and worldwide leads a reader to assume this trend continues everywhere. It does not. They also write “since 1980 a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous..”. This is the kind of inaccurate reporting that Climate Science is responding to on this theme of glacier retreat.

Climate Science has so far documented the following examples of recent and current glacial advance or near stationary movement within the following regions:

1a. Himalayas

1b. Himalayas

2. Alps

3. New Zealand and Norway

4. Palmer Peninsula, Antarctic

5. Mt. Kilimanjaro, Africa

6. Alaska, USA

This information is not presented to refute the conclusion that humans are altering the climate system. Indeed, Climate Science has emphasized that the 2007 IPCC seriously understates the role of the wide diversity of human climate forcings. However, honest assessments of climate require that the range of observed environmental conditions be reported, not just those that are convenient to support a particular narrow perspective.

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