Monthly Archives: July 2006

Is the Tropical Cyclone Data Adequate to Assess Multi-decadal Trends in Intensity?

A July 28 2006 Science Perspective article entitled “Can We Detect Trends in Extreme Tropical Cyclones?” (subscription required) by Christopher W. Landsea, Bruce A. Harper, Karl Hoarau and John A. Knaff has appeared. It raises the very real issue of the temporal homogeneity of the hurricane intensity data.

Among their findings,

“the 1970 Bangladesh cyclone—the world’s worst tropical-cyclone disaster, with 300,000 to 500,000 people killed—does not even have an official intensity estimate, despite indications that it was extremely intense.”

This is a remarkable finding. It not only supports the Landsea et al conclusions on the change of intensity assessments over time, but that in terms of what actually matters to people, this tropical cyclone, regardless of its intensity, caused a massive loss of life. The reduction of this loss should be a priority. Clearly changes in energy policy, such as CO2 reduction, will have much less of an impact on future loss of life, than improved plans to reduce the vulnerability of the local population to this risk (e.g. see).

Also, during the early 1970s, I had the privilege to work in the same building in Coral Gables, Florida as the National Hurricane Center. The Directors at this time, Dr. Robert H. Simpson and Neal Frank had the vision to permit the other researchers in the NOAA center (including me) to observe the hurricane specialists as they prepared their forecasts. Except during an immediate landfall event, we had unfettered access. The availability of satellite and reconnaissance aircraft to assess intensity even in the Atlantic tropical cyclone basin was notably different than what became available later. Thus the Landsea et al report resonates with my experience with the changes over time in the intensity data even in the Atlantic basin.

In my books on hurricanes,

Pielke, R.A., Jr. and R.A. Pielke, Sr., 1997: Hurricanes: Their nature and impacts on society. John Wiley and Sons, England, 279 pp.

Pielke, R.A., 1990: The hurricane. Routledge Press, London, England, 228 pp.

the reduction of the loss of life in the USA during the 2oth century is documented. This reduction can be credited both to improved construction and coastal planning (such as hurricane evacuation routes), and, to the significant advances in hurricane track forecasting by the National Hurricane Center.

The allocation of research funds to the reduction of societal risk to hurricanes, including the further improvement of hurricane track and intensity forecasting for individual storms, as well as effective coastal planning, should be high priorities. Large spending on multi-decadal hurricane intensity forecasts, relative to these other issues in tropical cyclone research, is a poor choice to provide benefit to society.

As shown on the Climate Science weblog, these multi-decadal global climate forecast models have shown no skill on the regional scale (e.g. see). The recent papers that claim to find a trend in hurricane intensity have no basis with respect to the multi-decadal global model predictions. The Landsea et al paper indicates that the the conjecture of a strong human influence on trends in hurricane intensity are based on temporally inhomogeneous observational data.

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Another Peer Reviewed Paper That Raises Questions On The Robustness of Multi-decadal Land Surface Temperature Trend Assessments

A March 2006 paper in the Journal of Climate by K.E. Runnalls and T.R. Oke entitled “A Technique to Detect Microclimatic Inhomogeneities in Historical Records of Screen-Level Air Temperature” further demonstrates significant problems with the accurate quantification of multi-decadal land surface temperature trends (and thanks to Dev Niyogi and Paolo M. for alerting me to this paper).

The abstract reads,

“A new method to detect errors or biases in screen-level air temperature records at standard climate stations is developed and applied. It differs from other methods by being able to detect microclimatic inhomogeneities in time series. Such effects, often quite subtle, are due to alterations in the immediate environment of the station such as changes of vegetation, development (buildings, paving), irrigation, cropping, and even in the maintenance of the site and its instruments. In essence, the technique recognizes two facts: differences of thermal microclimate are enhanced at night, and taking the ratio of the nocturnal cooling at a pair of neighboring stations nullifies thermal changes that occur at larger-than-microclimatic scales. Such ratios are shown to be relatively insensitive to weather conditions. After transforming the time series using Hurst rescaling, which identifies long-term persistence in geophysical phenomena, cooling ratio records show distinct discontinuities, which, when compared against detailed station metadata records, are found to correspond to even minor changes in the station environment. Effects detected by this method are shown to escape detection by current generally accepted techniques. The existence of these microclimatic effects are a source of uncertainty in long-term temperature records, which is in addition to those presently recognized such as local and mesoscale urban development, deforestation, and irrigation.”

In the conclusions, it is stated,

“Gradual changes in the immediate environment over time, such as vegetation growth, or encroachment by built features such as paths, roads, runways, fences, parking lots, and buildings into the vicinity of the instrument site typically lead to trends in the cooling ratio series. Distinct régime transitions can be caused by seemingly minor instrument relocations (such as from one side of the airport to another, or even within the same instrument enclosure) or due to vegetation clearance. This contradicts the view that only substantial station moves, involving significant changes in elevationand/or exposure are detectable in temperature data. It is not surprising that small station moves, even without changes of elevation or exposure, are capable of introducing inhomogeneities into the record,because there are often several confounding changes occurring at the same time. For example, a stationmove often coincides with screens being repainted, cleaned, or replaced, new instruments installed, and observers being reinstructed about their practices. Further, it is common for the new instrument site to bewithout grass for a few years, and there are many indications of muddy conditions around the instruments until grass is both planted and properly maintained. These factors, combined with subtle changes in the immediate surroundings (such as moving away from a parking lot or building), appear to be a significant causeof inhomogeneities in temperature records As isolated occurrences, activities such as painting, cleaning, or releveling screens or instruments do not frequentlycause significant changes to cooling régimes.”

“We suggest these effects are possibly underappreciated by many agencies responsible for maintaining the qualityof climatological records. Whether such small thermal effects amount to a significant concern largely dependsupon whether by their nature they are biased. That is, ifthe majority of the anomalies tend toward net warmingor net cooling. If they do, even tenths of a degree in onedirection take on real significance in the global climate change debate. Intuition, experience, and review of classic microclimatic case studies (e.g., Geiger 1965)suggests to us that the net impact of the most commonchanges (compaction due to trampling, increased paving,tree growth, removal or soiling of snow cover, construction of buildings and introduction of irrigation)lead to alteration of nocturnal controls on the surface heat balance (thermal admittance, sky view factor androughness and shelter) in ways that reduce nocturnal cooling and consequently increase the minimum temperature.Removal of trees and desiccation will act in the opposite direction. Are the environments of climatestations preferentially modified during the inexorableprocess of development in a way that leads to net thermalimpacts? We suspect they are, but the question deserves attention and objective analysis.”

“This study suggests that it might be beneficial to reexamine stations that passed previous homogeneity analyses and to consider the implications of the concerns raised by the work here for the large databases ofair temperature data that are assumed to be homogeneous and unbiased.”

The CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“, despite my urgings to the contrary (see) , chose to inadequately investigate the robustness of the land surface temperature data as a metric to use for accurate multi-decadal surface temperature trends. The Journal of Climate paper further shows that significant problems exist with the robustness of this data set with respect to the assessment of mutli-decadal evaluations of global warming variability and trends.

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What If Global Cooling Occurs?

There has been general conclusion that the global climate will warm more-or-less monotonically in the coming decades. This forecast is based on the predictions of the multi-decadal global climate models, such as summarized in the IPCC reports.

As concluded on the Climate Science weblog and in the peer reviewed literature (e.g see), the changes in ocean heat storage can be used as an effective metric to monitor climate system heat changes. The heat changes, measured in Joules, can be used to evaluate the radiative imbalance of the climate system in Watts per meter squared (see Figure 2 on page 333).

From the Willis et al 2004 paper, we know that the oceans warmed from mid-1993 through mid-2003, which continued a general increase over time since the mid-1950s. This global warming has been used as a foundation to claim that we understand the global climate system and can accurately predict the consequences of the diverse human forcings of the climate (e.g. see and see).

But what if the global average of the upper level of the oceans have cooled since mid-2003? What would be the consequences of such an observation? A recent presentation by Josh Willis at the Oceans Sciences meeting in Honolulu this year shows that the upper ocean has cooled significantly between 2003 and 2005.

Does this mean we should stop seeking alternative energy sources from fossil fuels. Should we stop pursuing energy efficiency? Should we advocate an increase in CO2 emissions to “combat” global cooling?

Hardly!

This straightforward “what ifâ€? clearly illustrates the need to pursue alternative energy to reduce our dependence on fossil fuels, and improve energy efficiency, regardless of whether we have global warming and cooling.

We need to separate climate policy from energy policy. This would permit the eight summary bullets that headline the Climate Science weblog to be assessed by the IPCC and the CCSP, rather than continuing to focus on the narrower perspective of long term effects of well-mixed greenhouse gas concentrations (see for a discussion of the need to change the current approach to climate policy).

As is discussed on the Climate Science weblog, the IPCC is not adequately assessing the role of the spectrum of diverse first-order human influences on the climate system, which is much more than the radiative effect of anthopogenic CO2. The observation of a significant cooling of the upper ocean should finally convince them to expand their perspective on climate variability and change.

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New Paper on the Role of Land Use on Climate

A July 2006 Geophysical Research Letters (GRL) paper has appeared entitled “Changes in moisture and energy fluxes due to agricultural land use and irrigation in the Indian Monsoon Belt” by Douglas, Ellen M.; Niyogi, Dev; Frolking, S.; Yeluripati, J. B.; Pielke, Roger A., Sr.; Niyogi, Nivedita; Vörösmarty, C. J.; Mohanty, U. C.

The abstract reads,

“We present a conceptual synthesis of the impact that agricultural activity in India can have on land-atmosphere interactions through irrigation. We illustrate a “bottom upâ€? approach to evaluate the effects of land use change on both physical processes and human vulnerability. We compared vapor fluxes (estimated evaporation and transpiration) from a pre-agricultural and a contemporary land cover and found that mean annual vapor fluxes have increased by 17% (340 km3) with a 7% increase (117 km3) in the wet season and a 55% increase (223 km3) in the dry season. Two thirds of this increase was attributed to irrigation, with groundwater-based irrigation contributing 14% and 35% of the vapor fluxes in the wet and dry seasons, respectively. The area averaged change in latent heat flux across India was estimated to be 9 Wm−2. The largest increases occurred where both cropland and irrigated lands were the predominant contemporary land uses. “

In the conclusion we state,

” The potential implications of flux changes reported in this study are consistent with the interpretation from similar work in other regions of the world [e.g., Marshall et al., 2004; Adegoke et al., 2003]. In addition to alterations in the surface heat and moisture fluxes due to regional land-scape change, the spatial heterogeneity of such a change also influences rainfall patterns [e.g., Segal et al., 1989; Lohar and Pal, 1995; Pielke, 2001]. These flux and rainfall alterations, when they cover a large enough area, can result in teleconnection effects which influence monsoon and global circulations [e.g., Fu et al., 2004; Chase et al., 2003].

Following the vulnerability paradigm used to assess risks associated with environmental/societal resources [Kabat et al., 2004; Pielke et al., 2006], we identified linkages and interactions with economic, societal and water resource factors that need to be investigated in more detail in future work. With this ‘‘bottom up’’ approach, the threats to a resource are identified such that procedures can be developed to reduce the risk to both natural and human systems that depend on them.”

The previous IPCC reports did not adequately address this issue in the past. Climate Science recommends that they include this perspective as a starting point in the IPCC report that is under development.

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Erroneous Presentation of My Views on Climate In the Media

A press release by Paradise Post reported on an important problem with the lack of a balanced presentation of climate science in the media. However, there are several falsehoods that are included with respect to my views. A correction is essential.

The news release stated

” He says most scientists are not willing to claim global warming is the fault of humans and their lifestyle.”

This is not my perspective. As I have summarized on the Climate Science weblog, humans activities do significantly alter the heat content of the climate system, although, based on the latest understanding, the radiative effect of CO2 has contributed, at most, only about 28% to the human-caused warming up to the present. The other 72% is still a result of human activities!(see).

The article stated,

“The professor also challenged recommendations made at the end of the program to reduce atmospheric emissions of carbon dioxide, saying such a program is really a waste of time and energy.”

I never made such a challenge. Indeed, I endorse the development of alternative energy and energy efficiency, both of which could save us money, reduce our dependence on foreign fossil fuel, as well as reduce emissions of gases and aerosols into the atmosphere, including CO2 (see).

The attribution to me of the statement

“Their theories have been disputed by former colleagues and a current co-worker, according to Pielke, who noted, “Oppenheimer serves as an adviser to a left-wing activist group, Environmental Defense.”

is wrong. I never made this statement. To place quotes around statements that I did not make is completely unacceptable and inappropriate.

The press release could have made their points without creating fictional quotes and views that I did not make.

I am sorry to see that media bias exists on all sides of the presentation of views on climate.

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Complete News Article On the Santa Fe Conference “Global Warming and the Next Ice Age?

The complete version of the news report on the Santa Fe meeting, form which the Associated Press article was extracted, was published in the Albuquerque Journal on July 23, 2006. This excellent, balanced article is entitled “Is It All Just Hot Air?” (subscription required) by John Fleck and reads,

” SANTA FE Greenland has become global warming’s poster child: rising temperatures melt glaciers, threatening a devastating rise in sea levels that could inundate coastal cities around the world.

Greenhouse gases from factories and cars are to blame, according to the conventional story, which features prominently in Al Gore’s documentary, “An Inconvenient Truth.”

And yet there was Los Alamos National Laboratory climate scientist Petr Chylek last week, standing before a gathering of his colleagues to explain that Greenland isn’t actually warming.

What gives?

Chylek is a dissenter from the scientific mainstream. While most scientists think greenhouse gases are responsible for changes already seen in Earth’s climate, Chylek believes the “data are inconclusive.”

“You really cannot say for certain what is causing current climate change,” Chylek said in an interview.

The Greenland story gained traction in February, when a team of U.S. scientists drew headlines around the world with new data suggesting Greenland’s glaciers are melting and slipping into the ocean far more rapidly than previously thought.

Chylek shot back last month with evidence from Greenland temperature records showing the North Atlantic island was cooler in the second half of the 20th century than it was in the first.

The exchange is the sort of thing that happens all the time in science: researchers doing their best to make sense of imperfect and sometimes conflicting data.

But this is not just any science. In climate science, the debate over whether we need to change global energy production to reduce greenhouse gas emissions turns ordinary scientific disagreements into political minefields.

By all measures, there is widespread agreement among climate scientists on key points:

The Earth is warming.

Human exhaust? primarily carbon dioxide, a “greenhouse gas” that holds heat close to the Earth’s surface? is likely a big part of the reason.

The more exhaust we spew, the more temperatures will go up. But when you get into the details, as Chylek is quick to tell you, you find that climate science is not a monolith:

Could changes in the sun be responsible for some of the warming?

While scientists obsess over greenhouse gases, are they missing other things that could be having equally large effects on the climate?

Are the thermometer records that show warming as good as scientists think they are?

Contrary to the common perception of textbooks filled with fixedknowledge, real science is a tangled process fraught with uncertainties, and such debates are common in any field.

“Science,” said Texas A&M climate scientist Andrew Dessler, “is this turbulent interface between what we know and what we don’t know.”

But if all science is turbulent, then climate science, because of its political dimensions, is all the more so.

Chylek placed that turbulence center stage last week, inviting more than a hundred scientists from around the world to Santa Fe for the 2nd International Conference on Global Warming, to discuss what scientists know and don’t know about our changing climate.

He understands his views place him in a minority among his scientific colleagues.

Chylek opened the interview with the Journal by pointing out, carefully and firmly, that he speaks for himself on these questions, not for Los Alamos.

“We have many people in the lab who completely disagree with me,” he said.

The conference, he said, was an attempt to recognize that a range of legitimate scientific views exists on global warming, and to encourage a discussion. To do that, Chylek invited both supporters of the mainstream view, as well as the most well-known skeptics.

Participants agreed Chylek achieved his goal.

“This is about one of the most diverse conferences there is,” said University of Alabama climate scientist John Christy, perhaps the most prominent of the global warming renegades.

The range of views held by working climate scientists does not show up in the political version of the debate, according to Roger Pielke Jr., a University of Colorado political scientist who studies the politics of climate science.

The science becomes caricatured, according to Pielke, dichotomized into “skeptics versus alarmists … even though it does not do justice
to the complexities of the science debate.”

Pielke has the pedigree to hold forth on the issue. His father,
Roger Pielke Sr., is one of those hard-to-pigeonhole climate renegades.

A tiff the elder Pielke had last summer with The New York Times illustrates the problem. In a story, the Times characterized Pielke
Sr. as “a scientist who has long disagreed with the dominant view that global warming stems mainly from human activity.”

Pielke Sr.’s views are not nearly so black and white, and he demanded a correction. The result: It took the Times 74 words to correct the initial 18-word description.

“Humans are having a significant effect on the climate system,” Pielke Sr. said in an interview during a break in Chylek’s conference.It’s a view that would seem to place him firmly in the mainstream. But it is not that simple.

Pielke Sr. thinks greenhouse gases are not the whole story. Massive human land-use changes? wholesale shifts from forest to agriculture, for example? are also important but are being given short shrift because of the emphasis on greenhouse gases.

Pielke Sr. also thinks global temperature data, the backbone of global warming claims, are fraught with uncertainties. And he is skeptical of the computer climate simulations used to forecast future climate change.

All of those legitimate scientific questions are lost in the simplified black-and-white version of climate science that shows up in
public discourse, Pielke Sr. believes.

So what should the public, policymakers and politicians make of this debate, given the argument by some that there is enough scientific evidence to support action to reduce exhaust emissions?

The first thing is to recognize that the sort of renegades Chylek invited to his conference are honest scientists raising serious questions, said Chick Keller.

The second is to recognize the context surrounding the questions they are raising. While the questions are legitimate, they are not sufficient to undermine the vast evidence for greenhouse-caused global warming, said Keller, a retired Los Alamos National Laboratory climate modeler and a veteran of the climate science wars.

“The trouble with the Chyleks and the Pielkes and to some extent Christy is they’re nitpickers,” Keller said in an interview. “You can always find something wrong.”

Pielke Sr., Chylek and Christy obviously don’t think they’re picking nits. So how should the public and policymakers, whipsawed by debate, sort out the competing claims?

“That’s easy,” said Dessler, co-author of Cambridge University Press’s “The Science and Politics of Global Climate Change.”

Dessler calls for the use of “expert assessments”? panels of specialists brought together to sort out and summarize scientific information for politicians, policymakers and the public.

It’s a common technique on all sorts of science-policy questions. On climate change, a number of such reviews have been done, including work by the Intergovernmental Panel on Climate Change and the NationalAcademy of Sciences.

The panels’ findings have been consistent and are reflected in the key finding in the IPCC’s 2001 “Climate Change: The Science”:
Greenhouse gas emissions are altering Earth’s climate.

Pielke Sr. has a different answer? listen to more diverse scientific voices. He thinks expert panels like the IPCC are inbred, representing a narrow focus on greenhouse gases.

“The public is getting a very narrow view of the breadth of issues in climate science,” he said.”

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Press Release On The Santa Fe Conference on “Global Warming and the Next Ice Age”

“The Associated Press carried a very good news report on the Santa Fe Conference on “Global Warming and the Next Ice Age” (see).

I want to make a comment in response to a quote by Chick Keller. The news article reported,

“Chick Keller, a retired Los Alamos lab climate modeler, said the scientists invited to the conference are honest scientists raising serious questions. But, he said, while the questions are legitimate, they are not sufficient to undermine the vast evidence for greenhouse gas-caused global warming. ‘The trouble with the Chyleks and the Pielkes and to some extent Christy is they’re nitpickers,’ Keller said in an interview. ‘You can always find something wrong.’â€?

What Dr. Keller refers to as “nitpickingâ€? is the scientific method of hypothesis testing. Our research has investigated several major hypotheses that Dr. Keller dismisses without even commenting on. Apparently, Dr. Keller wants to trivialize by using the dismissive term “nitpicking” in order to avoid discussing the actual issues that remain unresolved in climate science.

I list several hypotheses here, that warrant a response from Chick Keller:

1. As was evaluated in the weblog of April 27 2006 “What Fraction of Global Warming is Due to the Radiative Forcing of Increased Atmospheric Concentrations of CO2?â€?;

Hypothesis-The human contribution to global warming up to the present from the radiative effect of added CO2 is estimated as at most 28 %.

2. As documented in Willis et al 2004, and discussed on the Climate Science weblog (e.g. see “Comments on the Jim Hansen “super-El Niño Predictionâ€?).;

Hypothesis-Most global warming has been in the Southern Hemisphere midlatitude oceans and north Atlantic.

3. As documented in Pielke and Matsui 2005 , and discussed on the Climate Science website (e.g. Why there is a Warm Bias in the Existing Analyses of the Global Average Surface Temperature) there is an amplified temperature increase in near surface air temperatures on light wind nights which is significantly larger than a temperature increase higher in the surface air;

Hypothesis-Thus there is a widespread warm bias in the use of minimum surface air temperatures as the assessment of global warming.

The Hypothesis

“Are Multi-Decadal Global Climate Simulations Hypotheses? Have They Been Tested, and, If So, Have the Hypotheses As Represented By the Models, Been Falsified?”

has already been discussed on the Climate Science weblog (see). It was concluded that,

“The broad conclusion is that the multi-decadal global climate models are unable to to accurately simulate the linear trends of surface and tropospheric temperatures for the 1979-1999 time period on the regional and tropical zonally-averaged spatial scale. Their ability to skillfully simulate the global averages surface and tropospheric temperature trend on this time scale is, at best, inconclusive. “

This hardly appears to be “nitpicking”!

I also refer Dr. Keller to the eight summary bullets that headline the Climate Science weblog, each of which can be posed as a hypothesis, and involve major issues in climate variability and change.

I look forward to seeing Chick Keller’s papers (or his referral to peer reviewed papers) which contradict these conclusions. Chick has been invited to write a guest weblog on the Climate Science weblog in response to my reply to his quote.

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