Monthly Archives: December 2006

Misrepresentation Of Climate Science To Canadian Policymakers -Part II

[Continuation of weblog of December 14, 2006]

3. TESTIMONY: “Weather predictions for ten days now are as accurate as they were for a day and a half back in the sixties when I started in this business.”

I completely agree that there has been very significant improvement to weather forecasting skill. However, Ian Rutherford has clearly overstated the achievement. When you do this, you raise questions about the accuracy of his other statements. Obvious examples of his overstatement include 1 1/2 day predictions of hurricane landfall versus a 10 day prediction of the hurricane landfalls. Certainly he cannot claim that a 1 1/2 day prediction of this weather event is as good as a 10 day prediction!

To further illustrate his overstatement, I have provided links below to quantitative evaluations of the improvement in weather prediction skill over the last few decades in the United States at the Hydrometeorological Prediction Center (HPC) of the National Centers for Environmental Prediction (NCEP).

Annual HPC Threat Scores 0.50″

Annual HPC Threat Scores 1.00″

Annual HPC Threat Scores 2.00″

Annual HPC Mean Absolute Errors Minimum Temperatures

Annual HPC Mean Absolute Errors Maximum Temperatures

One can infer from the long-term trend lines on the graphic of threat scores for one inch and more of precipitation in a 24-hour period that the skill of current forecasts for day 2 is of comparable accuracy to that of day 1 forecasts of about 25 years ago.

Improvement in accuracy is also apparent in predictions by HPC’s medium-range forecasters. A case in point is provided by the verification of forecasts of daily maximum temperature, found at For example, the accuracy of the day 7 forecasts in 2005 was comparable to that of the day 5 forecasts in the 1987-1991 time frame and close to that of the day 3 forecasts of the early 1970s.

These quantitative predictions demonstrate that, that improved numerical weather prediction has been a major scientific achievement. However, Ian Rutherford’s testimony exceeded reality.

A figure provided by Lauren Morone of NCEP presents the forecast day in which useful skill for each calander year (as defined by NCEP) is lost for 500 hPa heights in the Northern Hemisphere (see below). In 2005, this was a little more than 7 days. This is quite an achienvement! However, it contradicts the statement of Ian Rutherford, unless he claims that there was no forecast skill at 1 1/2 days in the 1960s!


Another example which illustrates that there is no skill for 10 day forecasts is shown below.




These quantitative predictions, therefore, demonstrate that, while I agree with Ian Rutherford that improved numerical weather prediction has been a major scientific achievement, when claims are made to policymakers that exceed reality, it weakens all of the claims made by that scientist.

4. TESTIMONY: “We’re talking about two different kinds of problems in physics. There’s an initial value problem and a boundary value problem. Weather prediction involves knowing accurately the initial conditions and extrapolating forward in time to impute the details of a weather forecast…..Climate people solved the boundary value problem where they changed the content of the composition of the atmosphere, the energy coming in and going out, and other parameters like that. It works.”

“So people who make the statement that we can’t predict the weather even, let’s say, ten days in advance, so how can we possibly predict the climate a century in advance are talking about apples and oranges.”

This is a clear misrepresentation of weather and climate modeling. Climate models include weather processes as a subset of the model. Even in the context of claiming that “Climate is the statistics of weather where you do a lot of averaging over time”, Dr. Rutherford is not correct. When we talk about the weather today, we still use statistics such as the daily average temperature. With multi-decadal mean temperatures, we are just referring to an different (longer) statistical averaging time.

Moreover, to characterize climate as a boundary value problem ignores peer reviewed papers which illustrate that climate predition is very much an initial value problem. Just one example is

Claussen, M., C. Kubatzki, V. Brovkin, A. Ganopolski, P. Hoelzmann, H.-J. Pachur, Simulation of an abrupt change in Saharan vegetation in the mid-Holocene, Geophys. Res. Lett., 26(14), 2037-2040, 10.1029/1999GL900494, 1999.

Further examples are discussed in

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.


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

Dr. Rutherford, unfortunately, appears unaware of this literature. At the very least, as Executive Director of CMOS, he should have presented other perspectives on climate science, even if he did not personally support those views.

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Our paper “Was the 2003 European summer heat wave unusual in a global context” Has Been Published

We have discussed this paper on earlier weblogs (see). The paper was published today by Geophysical Research Letters.

Chase T. N., K. Wolter, R. A. Pielke Sr., I. Rasool (2006), Was the 2003 European summer heat wave unusual in a global context?, Geophys. Res. Lett., 33, L23709, doi:10.1029/2006GL027470.

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Misrepresentation Of Climate Science To Canadian Policymakers -Part I

There was testimony on November 7, 2006 to the Canadian Parliament which seriously misrepresents aspects of climate science. Testimony on climate science that advocates political actions should be accurate.

The relevant testimony is by Ian D. Rutherford who is Executive Director of the Canadian Meteorological and Oceanographic Society(CMOS). Dr. Rutherford is a well respected scientist which makes the statements he presented in testimony all the more surprising.

Since the weblog is long, it is separated into two Parts which are posted today and tomorrow.

The testimony, which is part of the Q&A part, is available from the 39th PARLIAMENT, 1st SESSION Standing Committee on Environment and Sustainable Development

“[after 1040am]

Mr. Pablo Rodriguez (Honoré-Mercier, Lib.):
Thank you, Mr. Chair.

Mr. Rutherford, sometimes we hear certain people say that it’s hard to predict the weather for tomorrow or next week; how then can we predict the impact of climate change in 20 or 30 years? What do you have to say on that subject?

Mr. Ian Rutherford:
I’m very pleased to ask that question because it’s very easy to answer.


I’ll switch to English, if you don’t mind.

We’re talking about two different kinds of problems in physics. There’s an initial value problem and a boundary value problem. Weather prediction involves knowing accurately the initial conditions and extrapolating forward in time to impute the details of a weather forecast.

Climate is the statistics of weather where you do a lot of averaging over time. Climate predictions are made without any initial data. Data is only used in order to verify the predictions made by a climate model, which are made ab initio from pure physical principles. You model the earth, the atmosphere, turn on the sun, compute the physics of energy transfer, the circulation starts up, the atmosphere starts up very quickly, and the ocean takes a lot longer to start up. You actually simulate the climate from first physical principles without any data at all; data is used only to determine certain coefficients and parameterizations and to verify the results after the fact.

So people who make the statement that we can’t predict the weather even, let’s say, ten days in advance, so how can we possibly predict the climate a century in advance are talking about apples and oranges. Furthermore, the fact is we can predict the weather ten days in advance, and it is through the use of this numerical weather prediction model that we’ve been able to do that.

When I started my career as a weather forecaster, we couldn’t make a prediction beyond about 36 hours. We didn’t even try. Weather predictions for ten days now are as accurate as they were for a day and a half back in the sixties when I started in this business. That’s all due to being able to model what’s actually going on and solving the initial value problem.

Climate people solved the boundary value problem where they changed the content of the composition of the atmosphere, the energy coming in and going out, and other parameters like that. It works.

Mr. Pablo Rodriguez:
The science of climate change works and should be trusted.

Mr. Ian Rutherford: I think so.”

The issues which Dr. Rutherford inaccurately presented in his testimony include:

1. TESTIMONY: “Climate is the statistics of weather where you do a lot of averaging over time.”

As presented in the 2005 National Research Council report, the climate system is defined as

“The system consisting of the atmosphere, hydrosphere, lithosphere, and biosphere, determining the Earth’s climate as the result of mutual interactions and responses to external influences (forcing). Physical, chemical, and biological processes are involved in interactions among the components of the climate system.”

Dr. Rutherford even contradicts his answer in the Q&A section, where earlier in the presentation of his views he states,

“Another characteristic of the climate system is that the ocean component, because the earth is roughly 70% ocean, dominates climate processes, and it’s the time scale of the oceans that dominates the time scale of climate change.”

This later view is consistent with the 2005 National Research Council definition of climate. More importantly, as documented extensively on Climate Science, the narrow view of climate presented by Dr. Rutherford in his answer to a question fails to communicate that climate forcings and feedbacks involve much more than an atmospheric focused view of climate. This is misleading to the policymaker who is asking the question.

2. TESTIMONY: “Data is only used in order to verify the predictions made by a climate model, which are made ab initio from pure physical principles….You actually simulate the climate from first physical principles without any data at all; data is used only to determine certain coefficients and parameterizations and to verify the results after the fact.”

Climate models are engineering code and are not first principle models! The only basic physics in a climate model is the pressure gradient force, advection, the rotation of the Earth and the gravitational acceleration. All other components of the models (which include biological and chemical processes as well as physical processes) are parameterized.

The parameterizations include climate effects due, for example, to turbulence, clouds and precipitation, aerosol effects, vegetation, and sea ice. Each of these parameterizations contains tunable coefficients which Dr. Rutherford mentioned but did not emphasize how central this tuning of the parameterizations is to the climate model simulations. An overview of part of this issue is presented in Pielke, R.A., Sr., 2004: The Limitations of Models and Observations.

[the weblog on this topic continues tomorrow].

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Climate Effects of Regional Nuclear War – Another Example Of Why Climate Change Assessments Need to Move Beyond The Narrow Focus on the Radiative Effects of CO2

Two new important papers have appeared which present evidence for major climatic, environmemental and social consequences of even limited regional nuclear war. This issue is also discussed in the second edition of the book “Human Impacts on Weather and Climate” by William R. Cotton and myself which will appear from Cambridge University Press next month.

The two papers also reinforce a theme that has been emphasized on Climate Science. This is that

“The needed focus for the study of climate change and variability is on the regional and local scales. Global and zonally-averaged climate metrics would only be important to the extent that they provide useful information on these space scales.”


“Global and zonally-averaged surface temperature trend assessments, besides having major difficulties in terms of how this metric is diagnosed and analyzed, do not provide significant information on climate change and variability on the regional and local scales.”

The two papers are

“Climatic consequences of regional nuclear conflicts” by A. Robock, L. Oman, G. L. Stenchikov, O. B. Toon, C. Bardeen, and R. P. Turco, Atmos. Chem. Phys. Discuss., 6, 11817–11843, 2006 /

with the abstract

“We use a modern climate model and new estimates of smoke generated by fires in contemporary cities to calculate the response of the climate system to a regional nuclear war between emerging third world nuclear powers using 100 Hiroshima-size bombs (less than 0.03% of the explosive yield of the current global nuclear arsenal) on cities in the subtropics. We find significant cooling and reductions of precipitation lasting years, which would impact the global food supply. The climate changes are large and longlasting because the fuel loadings in modern cities are quite high and the subtropical solar insolation heats the resulting smoke cloud and lofts it into the high stratosphere, where removal mechanisms are slow. While the climate changes are less dramatic than found in previous “nuclear winterâ€? simulations of a massive nuclear exchange between the superpowers, because less smoke is emitted, the changes are more longlasting
because the older models did not adequately represent the stratospheric plume rise.”


“Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism” by O. B. Toon, R. P. Turco, A. Robock, C. Bardeen, L. Oman, and G. L. Stenchikov. Atmos. Chem. Phys. Discuss., 6, 11745–11816, 2006

with the abstract

“We assess the potential damage and smoke production associated with the detonation of small nuclear weapons in modern megacities. While the number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986, the number of nuclear weapons states is increasing and the potential exists for numerous regional nuclear arms races. Eight countries are known to have nuclear weapons, are constructing them, and an additional 32 nations already have the fissile material needed to build substantial arsenals of low-yield (Hiroshima-sized) explosives. Population and economic activity worldwide are congregated to an increasing extent in 10 megacities, which might be targeted in a nuclear conflict. Our analysis shows that, per kiloton of yield, low yield weapons can produce 100 times as many fatalities and 100 times as much smoke from fires as high-yield weapons, if they are targeted at city centers.
A single “smallâ€? nuclear detonation in an urban center could lead to more fatalities, in some cases by orders of magnitude, than have occurred in the major historical conflicts of many countries. We analyze the likely outcome of a regional nuclear exchange involving 100 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal). We find that such an exchange could produce direct fatalities comparable to all of those worldwide in World War II, or to those once estimated for a “counterforceâ€? nuclear war between the superpowers. Megacities exposed to atmospheric fallout of long-lived radionuclides would likely be abandoned indefinitely, with severe national and international implications. Our analysis shows that smoke from urban firestorms in a regional war would rise into the upper troposphere due to pyroconvection. Robock et al. (2006) show that the smoke would subsequently rise deep
into the stratosphere due to atmospheric heating, and then might induce significant climatic anomalies on global scales. We also anticipate substantial perturbations of global ozone. While there are many uncertainties in the predictions we make here, the principal unknowns are the type and scale of conflict that might occur. The scope
and severity of the hazards identified pose a significant threat to the global community.They deserve careful analysis by governments worldwide advised by a broad section of the world scientific community, as well as widespread public debate.”

These two papers also show why we need to move beyond the radiative effects of CO2 as the dominate threat of the 21st century. This theme, as exemplified by these two papers, supports the conclusions on Climate Science that

“A vulnerability paradigm, focused on regional and local societal and environmental resources of importance, is a more inclusive, useful, and scientifically robust framework to interact with policymakers, than is the focus on global multi-decadal climate predictions which are downscaled to the regional and local scales. The vulnerability paradigm permits the evaluation of the entire spectrum of risks associated with different social and environmental threats, including climate variability and change.”


“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. These assessments have also not communicated the inability of the models to accurately forecast the spread of possibilities of future climate. The forecasts, therefore, do not provide any skill in quantifying the impact of different mitigation strategies on the actual climate response that would occur.”

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Additional Evidence of the Complex Role of Vegetation in Climate Change

Another study has appeared which further confirms the complexity of climate. The study is reported on December 12, 2006 (see), and is titled

“Forests can raise earth’s temperature: US study”

and reads in part,

“The key to using trees to offset global warming is to expand tropical rainforests south of the equator, according to research released in the United States on Monday. ‘Our study shows that tropical forests are very beneficial to the climate because they take up carbon and increase cloudiness, which in turn helps cool the planet, ‘said Govindasamy Bala, lead author of the research.”

However, they add,

“Planting forests north of the equator appeared to either “zero-out” or be counterproductive in regard to global warming, according to researchers.”

The article continues,

“Scientists from the French Universite’ Montpellier II and the Carnegie Institution and Lawrence Livermore National Laboratory in the United States collaborated in the unprecedented study on the effects of deforestation on climate and atmospheric carbon.
Forests have been touted by environmentalists for their abilities to absorb carbon dioxide, a notorious greenhouse gas, and for exuding moisture that increases sun-blocking cloud cover.

Researchers involved in the study said the tendency for dark forest cover to absorb sunlight, thus warming the Earth, has been overlooked.

‘The darkening of the surface by new forest canopies in the high-latitude Boreal regions allows absorption of more sunlight that helps to warm the surface,’ Bala said. The study concluded that, by the year 2100, forests in mid- and high-latitudes will make some places up to 10 degrees Fahrenheit warmer than they would have been if the forests did not exist.

Planting forests in mid-latitude areas has been heavily promoted in the name of mitigating climate change caused by global warming, according to researchers.
The warmth from sunlight absorbed by forest canopies cancels out the positive effects from the trees taking in carbon, the study concluded.

‘Our study shows that preserving and restoring forests is likely to be climatically ineffective as an approach to slow global warming,’ said study co-author Ken Caldeira of the Carnegie Institution.”

This study further affirmed what was written in the article

Pielke Sr., R.A., 2001: Carbon sequestration — The need for an integrated climate system approach. Bull. Amer. Meteor. Soc., 82, 2021.. Bull. Amer. Meteor. Soc., 82, 2021,

and discussed most recently in the Climate Science weblog of November 27 2006,

“There has, unfortunately, been no attempt to evaluate the benefit of carbon sequestration as a means of reducing the concentrations of the radiatively active gas CO2 in the atmosphere, while at the same time, assessing the influence of this sequestration on the radiatively active gas H2O, and on the surface heat energy budget. Until these effects are factored in as part of an integrated climate assessment, a policy based on carbon sequestration as a means to reduce the radiative warming effect of increased atmospheric concentrations of CO2 could actually enhance this warming.”

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New Evidence Of Temperature Observing Sites Which Are Poorly Sited With Respect To The Construction Of Global Average Land Surface Temperature Trends

We have stated in the literature that photographic documentation of the observing site that are part of the global land surface temperature assessments is critically important, as we have identified poor instrument exposure with respect to the assessment of long term temperature trends; e.g. see

Pielke Sr., R.A., C. Davey, D. Niyogi, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, J. Angel, R. Mahmood, S. Foster, J. Steinweg-Woods, R. Boyles , S. Fall, R.T. McNider, and P. Blanken, 2006: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Research, submitted.

The National Climate Data Center (NCDC) has started a compilation of these photographs as part of the USA contribution to GCOS (Global Climate Observing System). As part of this effort a set of photographs have been archived (see).

I have selected a sample of them from that website (others can be obtained from their website). The Mexican photographs, in particular, are effective presentations which follow the format that we used in

Davey, C.A., and R.A. Pielke Sr., 2005: Microclimate exposures of surface-based weather stations – implications for the assessment of long-term temperature trends. Bull. Amer. Meteor. Soc., Vol. 86, No. 4, 497–504.

It is clear from the examples of the land surface temperature observation sites, that most are not appropriately sited to detect tenths of degrees of temperature changes per decade since their microclimate clearly is not likely to be stationary in time. Moreover, several sites are on rooftops.

Thus, while the temperature data certainly are very valuable for weather analysis, their use in the construction of a global surface land surface temperature trend is not appropriate. Peterson has claimed in

Peterson, T.C., 2006. Examination of potential biases in air temperature caused by poor station locations. Bull. Amer. Meteor. Soc., 87, 1073-1089.

that he can adjust poorly sited stations of this type, however, as we show in our response article to his paper,

Pielke Sr., R.A, J. Nielsen-Gammon, C. Davey, J. Angel, O. Bliss, M. Cai, N. Doesken, S. Fall, K. Gallo, R. Hale, K.G. Hubbard, H. Li, X. Lin, , D. Niyogi, and S. Raman, 2006: Documentation of bias associated with surface temperature measurement sites. Bull. Amer. Meteor. Soc., submitted.

no value is added from such sites. In addition, for locations where these poorly sited locations are the only data used to construct a grid area average in the global temperature trend data base, their use will introduce spatially unrepresentative data into the analyses.

Examples of the photographs are available from the following:

Lusaka Zambia

Katmandu Nepal

Nassau Bahamas

Grantley Adams Barbados

Owen Roberts Airport Grand Cayman

Acajutla, El Salvador

Veracruz, Mexico

Tampico, Mexico


Monterrey Mexico

Mexico City, Mexico

Merida, Mexico

Mazatlan, Mexico

Manzanillo, Mexico

La Paz, Mexico

Guanajuato, Mexico

Chihuahua, Mexico

Clearly, the exposure to nearby buildings, parking lots and other local structures makes the use of these locations to detect tenths of a degree per decade in surface temperature trends inappropriate.

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Comment By Franco Einaudi President of the American Meteorological Society With Respect To The Guest Weblog of Ross McKitrick

Franco Einaudi, Director of the Earth Sciences Division of the NASA Goddard Space Flight Center kindly has permitted me to post his comment on the Guest weblog of Ross McKitrick that was posted on Climate Science on November 23 2006.

“Dear Prof. McKitrick,

You have articulated well the point of view that when a society issues an official statement it creates two negative effects: 1) to allow “outside commentators to buttress their position by appeal to the “Expert Statement”, rather than by appeal to evidence; 2) to create divisions within the membership, limiting rather than encouraging open dialogue. There is some validity on both counts.

Let me give you my personal point of view. ( I am ending next month my serving as the elected president of the AMS). Our Society is a scientific and professional society made of three components equally divided among academia, government, and the private sector. Its goals as stated in the almost-completed new strategic plan are:

1. To advance scientific and technological knowledge and foster applications through first-class publications and meetings;

2. To catalyze and support sustained, interdisciplinary, multi-institutional collaborations among researchers and service providers for both national and international initiatives of socio-economic value to society;

3. To accelerate the development and utility of applications, products, and services;

4. To promote science-based decision making;

5. To create a more scientifically literate population;

6. To attract the best and the brightest people into the professions served by the AMS;

7. To develop greater synergies among all sectors of the enterprise;

You will note some overlapping with the goals of your Society, but you will also note substantial differences due to the nature of our membership and our fields. From its beginning in 1919, the AMS has had a dual role in research and applications. In addition to what one might call the traditional role of a scientific society in supporting science and applications through means such as refereed journals and scientific meetings, the Society has played an important professional society role in: i) the definition of best practices and professional standards, certification programs, and continuing professional development; ii) educational programs at various levels because of insufficient or non-existent curricula in our field; iii) the dialogue among academic, governmental and private sector, which requires the Society involvement in helping defining the optimal balance between government provided services (at taxpayers expense) and services provided by the private sector. This is a sensitive area that has inevitable policy and political overtones.

Some of the points above are not without controversy and different components of the membership have different interests and points of view.

A few years ago, the AMS developed a new program to improve the communication between scientists and policy makers and the media. It is well known that scientists in general do not communicate in a language that is well understood by the general public, including the media and policy makers. A simple and good example is the interpretation that the media give to the errors bars that scientists properly use to define the limitations of their results, but that are generally interpreted by the media as a level of uncertainty well beyond what was intended by the scientists. Members of Congress are often ignorant of our science and our products, and the AMS creates opportunities for policymakers and scientists to engage in a dialogue to foster better-informed policy decisions.

With this as a background, you should see the AMS Statements as a component of our attempts to support outreach and education. They are of three kinds; i) Professional Guidance Statements to inform AMS members about urgent AMS, professional or scientific matters; ii) Information Statements which are objective and scientifically up-to-date explanations of scientific issues of concern to the public at large. They are informational only and do not make recommendations or take positions on issues; and iii) Policy Statements which are aimed at representatives of local, state or Federal government, officials of international bodies and related policy professionals. They are often prepared in response to requests from government officials or initiated by AMS personnel or members. Their purpose may be:

o To advocate a position on science and technology issues of concern to the AMS members

o To provide analysis, articulate the state of scientific understanding, or express the concern of the scientific community about issues pertinent to a current public policy issue

o To raise awareness of a scientific issue with potential future policy implications

o To make policy recommendations based on the professional and scientific expertise and perspectives of the AMS.

Policy statements, and also informational statements, may form the basis for AMS testimony and briefings to government officials. Indeed the AMS is often asked to provide input on legislation introduced in Congress on items relevant to the AMS activities, on political appointments to Government agencies dealing with our activities much in the spirit of the American Bar Association is asked to provide input on the Supreme Court nominees. These are requests that are often delicate, and we always proceed with great deal of cautiousness.

A quick perusal of the titles of the Statements published in the last three years listed below:

o Freedom of scientific expression (2006)
o Earth Science Education (2006)
o Research and Operational Use of Environmental satellites in Weather Applications as Part of an Integrated Earth Observing System (2006)
o Endorsement of the “Joint Academies” Statement: Global Response to Climate Change” (2005)
o Bachelor’s Degree in Atmospheric Science (2005)
o Mobile Homes and Severe Windstorms (2004)
o Tornadoes Forecasting and Warning (2004)
o Meteorological Drought (2004)

indicate that most of them are outlining programs in education or state-of-the-art reviews of the science and applications of given areas. The complete list of active AMS Statements can be found in the AMS Website.

Let me come to the last point I want to make. Your note was motivated by the request for comments on the draft AMS Statement on Climate Change. This is the most delicate topic that the Society has to deal with at present time. Our science, and I am sure yours as well, is often characterized by a very fine line between pure research and policy implications because of the potential serious impact of weather and climate on agriculture, water availability and distribution, air quality, infectious diseases, transportation, various industries, and commerce. When a scientist runs a numerical model to predict climate conditions 100 years in the future and discusses the implication of the results, it is inescapable that considerations on the technology available and the economic impacts become an integral part of the discussion. Implied policy implications at times become implicit in the eye of the reader if not in the intentions of the scientist.

As you well know, the reality is that economists are beginning to identify the environment as one of the fundamental elements that influence economies in both developing and developed nations. Policy decisions on technology investments and/or environmental regulations have a profound economic impact. The wisdom of those decisions depend in part on information that our community provides. As stated in the AMS Strategic plan, our success will depend on our ability to make progress in our science and to provide policy makers with reliable and convincing information about it. Informing policy decisions is both an opportunity and a challenge for the AMS. The opportunity is to attract new members to our Society who will strengthen the connection between public policy and our science and products. The challenge is to achieve the needed policy ends without sensationalizing or politicizing the impacts of the research findings. Accurate and fair AMS Statements are part of that challenge. And so is the need to perform in such a way as to minimize the negative impacts that you point out in your letter.

Thank you for intervening in the debate.


Franco Einaudi

Franco Einaudi, Director
Earth Sciences Division, Code 610
NASA Goddard Space Flight Cente

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Another Paper That Documents Why Land Use/Land Cover Change Must Be Part of Global Climate Assessments

A new paper has appeared in Global Biogeochemical Cycles entitlted

“Comparative impact of climatic and nonclimatic factors on global terrestrial carbon and water cycles” by Christoph Muller, Alberte Bondeau, Hermann Lotze-Campen, Wolfgang Cramer, and Wolfgang Lucht in VOL. 20, GB4015, doi:10.1029/2006GB002742, 2006

which provides even further deomonstration on the first order role of land use/land cover processes within the climate system.

The abstract of this paper states,

“The coupled global carbon and water cycles are influenced by multiple factors of human activity such as fossil-fuel emissions and land use change. We used the LPJmL Dynamic Global Vegetation Model (DGVM) to quantify the potential influences of human demography, diet, and land allocation, and compare these to the effects of fossil-fuel emissions and corresponding climate change. For this purpose, we generate 12 land use patterns in which these factors are analyzed in a comparative static setting, providing information on their relative importance and the range of potential impacts on the terrestrial carbon and water balance. We show that these aspects of human interference
are equally important to climate change and historic fossil-fuel emissions for global carbon stocks but less important for net primary production (NPP). Demand for agricultural area and thus the magnitude of impacts on the carbon and water cycles are mainly determined by constraints on localizing agricultural production and modulated by total demand for agricultural products.”

The 2006 Muller et al paper confirm the role of land use/land cover as a first-order climate forcing, such as discussed in Pielke Sr., R.A., 2005: Land use and climate change. Science, 310, 1625-1626.

Excerpts from the Muller et al paper state,

“Agricultural land use is a major factor influencing the global carbon and water cycles: in the case of carbon, potentially equally important to historic fossil-fuel emissions and projected climate change. The size of agricultural land is the most important aspect of agricultural land use for the terrestrial carbon and water cycles. It is therefore crucial for assessing effects of land use and land use change to correctly determine the size of agricultural area, taking into account all drivers that determine land use patterns……. Although the impacts of land use on the global carbon and water budgets are strongly related to the extent of total agricultural area, they cannot be assessed with crude estimates of total area demand. Population, consumption patterns, and especially the spatial constraints on land use determine total area demand in a nonlinear way.”

“Future studies on global change need to include spatially explicit patterns of human land use. Land use has been shown to affect climate change [e.g., Sitch et al., 2005] and the global carbon and water budgets (this study). Although not included in this study, technology change, climate change, and their mutual interaction with land use and the biogeochemical cycles presumably affect the magnitude of each other’s impact and need to be studied in a comprehensive framework.”

This study illustrates why climate assessments such as the IPCC reports need to consider the climate as a nonlinear system with mutiple, diverse climate forcings. As indicated in this study, and as reported in a NASA press release based on 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

land use/land cover change, as one of the first order climate forcings, may have a larger effect than the radiative effect of added carbon dioxide and other well-mixed greenhouse gases, on aspects of the climate system that matter the most to society and to the environment.

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Climate Forcings As Viewed From Space

There is an interesting interview with Piers Sellers entitled “Life in space” on Times on Line on November 25, 2006.

Dr. Sellers, who is a well known, respected climate scientist, and is now an astronaut, made the following interesting comments on the pollution that he saw from orbit (the entire interview is a candid discussion of his experiences and is well worth reading);

“H: Is it true that you can see pollution?
P: Yes. Over London, whenever I’ve seen it, looked pretty clear. So stopping all those coal fires was probably a good thing.

H: Can you see any pollution?
P: Yes. Ferocious. Over the Chinese industrial belt. Big, thick yellow cloud, you can scarcely see the surface. I mean it looks like tobacco smoke. It looks terrible. Some of the Russian cities, in the east you can see a plume of grey blowing downwind from them. European cities and the American cities, pretty clean. On the whole. So 20 years of environmental effort, or 30 years I guess, have cleaned them up quite a lot. You don’t see any industrial plume or haze coming off Europe.

H: Do you see that as part of your role?
P: No, no role. My role when I’m up there is to be space walker and get my job down as efficiently as I can. When I come back, I spend most of my life as a climate scientist. Global warming guy. Didn’t give me any particular insights, but it was beautiful to see something you’ve studied in theory in front of your own eyes. All working. All the little cloud systems, the hurricanes, the tropical…

H: But for a climate scientist to see all that pollution, must be hard.
P: See the pollution, Shanghai, that was kind of sobering. Beijing and Shanghai. As an academic I was working my whole life on the business of trying to explore the impacts of man’s activities on the climate system. To be honest, the kind of pollution that you can see from orbit is bad for the people who are living under it. But we all of us generate a lot of carbon dioxide which is changing the climate, and you can’t see that from space.

H: What’s the carbon footprint like of the space shuttle?
P: Pretty small, I would think. All the carbon dioxide we generate we dump overboard on the space station. Carbon footprint is more like a toe print. ”

Dr. Seller’s statement that

“To be honest, the kind of pollution that you can see from orbit is bad for the people who are living under it. But we all of us generate a lot of carbon dioxide which is changing the climate, and you can’t see that from space.”

illustrates the continuing perspective that the aerosol pollution only affects those who are living under it. As reported in the 2005 National Research Council Report

“Linkages between weather or climate changes occurring in widely separated regions of the globe are referred to as teleconnections. The extent to which regionally concentrated radiative forcing can affect climate via teleconnections is a matter of current research. Determining the importance of regional forcings, such as those from aerosols or land-use change, requires an understanding of the role of teleconnections that can lead forcings in one region to have effects on other regions far away. Teleconnections are most commonly thought of with respect to the transport of energy by atmospheric waves (Tsonis, 2001). For example, regional and global weather patterns have been associated with sea surface temperature anomalies (e.g., Hoerling and Kumar, 2003). Radiative and nonradiative forcing due to regional land-use change can also result in large differences in atmospheric circulation patterns at large distances from the landscape disturbance. For example, land-use change can alter deep cumulonimbus patterns, which affect atmospheric circulation in distant regions (Chase et al., 2000a).”

The role of human caused climate forcings on teleconnections are also, as with the well-mixed greenhouse gases, including carbon dioxide, not visible from space.

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New Paper On North Atlantic Ocean Heat Content Changes

A new paper has appeared which provides both support for the paper Lyman, J. M., J. K. Willis, and G. C. Johnson (2006), “Recent cooling of the upper ocean“, and adds new insight into the variability and multi-year trends in ocean heat data [thanks to Willie Soon and Steve Bloom for alerting me to this paper]. The paper is

Ivchenko V. O., N. C. Wells, D. L. Aleynik (2006), Anomaly of heat content in the northern Atlantic in the last 7 years: Is the ocean warming or cooling?, Geophys. Res. Lett., 33, L22606, doi:10.1029/2006GL027691

with the abstract,

“Whether the North Atlantic Ocean is warming or cooling is an important question both in physical oceanography and climate change. The Argo profiling buoys provide an accurate and stable instrument for determining the tendencies in heat content from the surface to 2000 m from 1999 to 2005. To calculate temperature and heat content anomalies two reference climatologies are used. These are the well known WOA2001 climatology (Stephens et al., 2002), and a new WOCE Global Hydrographic climatology (Gouretski and Koltermann, 2004). The former climatology is used for our main results, and the latter is used for evaluating the sensitivity of our results to the climatology. Our scheme allows us to estimate the anomaly of heat content (AHC) in the North Atlantic and its smaller sub-domains (i.e. 10° boxes) for the period 1999–2005. We have found a dipole structure in the time averaged AHC: negative values are concentrated in the southern and middle latitudes of the North Atlantic whilst positive values are found north of 50°N. The upper 1500 m of the North Atlantic is warming throughout the period 1999 to 2005.”

The text states that,

“We have found a negative AHC for the upper 1500 m for the period of time 1999–2005 relative to the climatology. Why is it negative? First of all, the space distribution of the AHC in the Northern Atlantic shows variability, with both positive and negative anomalies. In particular there is a dipole type distribution of the time averaged AHC with negative values concentrated in the southern and middle latitudes of the North Atlantic and positive values north of 50°N…”

“Secondly, despite the overall positive trend of the heat content in the North Atlantic, there were periods of several years when the heat content decreased substantially…”

“Thirdly, the climatology comprises observations from very different instruments, including XBT. It was shown by V. Gouretski (private communication, 2006) and V. V. Gouretski and K. P. Koltermann (How much is the Ocean really warming?, submitted to Geophysical Research Letters, 2006) that the XBT data has a positive temperature bias when compared to CTD data. The XBT data, since the 1970s contributed substantially, to the total set of all North Atlantic data and therefore this positive bias may have a significant influence on the climatological temperature”.

The three reasons for the negative AHC mean:

1. There are large regional variations in climate forcings and feedbacks, as has been emphasized, for example, in Matsui, T., and R.A. Pielke Sr., 2006 and in NRC 2005. Figure 4 in Ivchenko et al very effectively summarizes this regional north-south variation using zonal averages.

2. The temporal variations of the ocean heat content are not well represented by linear trend analyses, as also reported in Pielke Sr., R.A., 2003: Heat storage within the Earth system and Willis, J.K., D. Roemmich, and B. Cornuelle, 2004: Interannual variability in upper ocean heat content, temperature, and thermosteric expansion on global scales. See, for example, the very recent cooling in the latitude band 60-70N and 20-40N in Figure 4 in Ivchenko et al. Such variations need to be skillfully simulated by the models as a necessary condition for skillful forecasts of climate in the coming decades.

3. There is a warm bias in one of the instruments (according to two papers which have not yet appeared), which raises questions regarding the values of the heat content obtained in earlier years.

The Ivchenko et al article also provides support for the value of the Argo temperature profiles (see here for information on the Argo Ocean Monitoring Network) and in the values of ocean heat content change reported in Lyman, J. M., J. K. Willis, and G. C. Johnson (2006), Recent cooling of the upper ocean [see their Figure 2] which also show strong warming in the northern part of the North Atlantic and cooling further south.

Ivchenko et al conclude their paper by stating that,

“The vertical structure of the warming/cooling in the last 7 years is rather complicated. The top 100 m demonstrates substantial warming in the southern part, but also substantial cooling beneath this layer down to 1000 m. The exciting result is that the warming takes place in all the studied layers in the northern part of the domain. The strongest signal is associated with the upper ocean.”

The authors are focusing at the end of their paper on the significant long term warming of the northern part of the domain. This is an important finding. However, just as exciting is that the robustness of the Argo Ocean Monitoring Network is shown, that there is no trend or a cooling trend at the lower latitudes, and that the analyses reported in Lyman et al appear to be consistent with the spatial pattern of ocean heat content change found in the Ivchenko et al paper.

At the December 2006 AGU meeting, there certainly will be further discussion of this topic in the Session “Oceans in a Changing Climate: Global Heat and Freshwater Budgets” .

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