Saturday, December 10, 2011

Yep, it's getting warmer


In a recent issue of Science a trio of scientists who are experts on climate modeling and interpretations of data related to global climate summarize the best available information on variation in Earth’s surface temperature over the past half century or so. Their work addresses a controversial subject that those resisting the idea of global warming love to talk about.
Doubts about the reality of 20th century warming have been fueled by a veritable blizzard of misinformation and outright denial by politicians such as Senator James Inhofe and talk show hosts such as Rush Limbaugh and Glenn Beck. The political winds from the extreme right have been blowing so mightily against the notion of global warming that the front-runners in the race for the Republican nomination in 2012 seem to be obliged to join in the denialist chant. The American people are being deluged with misinformation and outright lies on this topic. It is thus worth thinking about the significance of this recent work by Santer, Wigley and Taylor.
One of the most difficult challenges in the entire business of drawing conclusions about Earth’s surface temperature is that there really is no single literal measurement that gives us the temperature of the planet. I wrote about this in Chapter 9 of my 2003 book, Making Truth: Metaphor in Science. When we want to measure our own body temperature, we insert a measurement device such as a thermometer, or one of the fancier digital probes, under our tongue, in our ear or up our rectum, as the case may be. The temperature we record in this way we take to be representative of our body as a whole. This works because our bodies are designed to maintain, as closely as possible, a single temperature throughout. But planet Earth is not like that. As I write this in Estero Florida the temperature is about 80 degrees Farenheit. At the same time, my daughter living in mid-central Illinois reports that the temperature there is about 11 degrees Farenheit. It is far colder still in Antarctica. No single value represents the surface temperature of the planet . For this reason, when we talk about the surface temperature of the planet we are using metaphorical language and thought. We talk aboutEarth’s surface temperature as though the planet were a small, temperature-controlled thing like a human body or a refrigerator.
To get to something that resembles a single value for the surface temperature, scientists began with simply averaging the temperatures measured at as many places as possible at the same time, and averaging over time as well. Before the modern age of satellite measurements the estimates were pretty crude. Consider that something like 70 percent of Earth’s surface is covered with water. How do we get sufficient measurements of the vast and varied seas to produce reliable numbers? And what about remote places that are not readily accessible, or crowded urban areas where human activity generates a good deal of local heat? With satellite measurements it has become possible to collect data over a short period of time that reflects surface temperatures
over most of earth’s surface. By averaging these in a suitable way, one ends up with a single number that we call the surface temperature of the planet. It’s a metaphorical entity, not a real single temperature, but its value over time can serve as a reliable measure of the change at Earth’s surface. However, the interpretation of satellite data is not entirely straightforward. A group of scientists at the University of Alabama at Huntsville concluded in 2005 from satellite data that the planet’s surface temperature had declined since 1979. This unexpected result was used to cast doubt on the reality of surface warming.
One of the hallmarks of good science is that controversial results are subject to reevaluation and continued exploration. The satellite measurements were a new technology, and many factors needed to be taken into account in interpreting the data. Climate scientists at a California laboratory identified two serious errors made by the Huntsville group in their analyses. These were acknowledged by the Huntsville scientists, who redid their recalculations. The corrected results showed a warming trend over the entire period 1979 to present. The revised estimate, following from critical scrutiny by other scientists, represents another step forward in our ability to measure and understand the evolution of the global climate.
Modeling the terrifically complicated global climate system is difficult. The challenge is to find a model that reproduces the historical record as well as possible, considering all the uncertainties,and then to use that model to forecast the future course of climate change, assuming various scenarios regarding levels of greenhouse warming gases, energy consumption, population growth and so on. The media are filled with confident pronouncements, for the most part self-serving, about climate change from political, ideological and financial interests. When we hear what people like Rush Limbaugh, James Inhofe or Newt Gingrich are saying or are ready to get behind, we need to ask what motivates them and what is their competence to speak on the issue at hand. We should also do that with respect to scientists, whatever the issue might be. Citizens need to go behind the one-liners of politicians and talk show personalities to learn what scientists think and the evidence that supports their views. There is no scientific conspiracy to deceive the public into believing that global warming is real, and that it has the potential to cause a great deal of human suffering. Scientists are just doing their work, trying to learn more about the way the world is.
An incredible amount of research across many scientific disciplines leads to an unambiguous result: the planet is warming, mostly because of increased concentrations of so-called greenhouse gases in the atmosphere. Denying this may be politically or financially expedient, but global warming is underway and it will gain strength with each passing year. How much adverse change occurs over the next 50 years and beyond will depend on whether humanity collectively decides to do something about continued generation of greenhouse gases. There is little hope for significant action in the near future. The 2011 Climate Change Conference in Durban, South Africa, just concluded with essentially no progress in setting mandatory goals for reductions of greenhouse gases. This should not surprise anyone. We humans have evolved to possess a strong consciousness of the future, but we still live very much in the present. Our proclivity to discount the future, particularly one so distant that we will not be there to live in it, prompts us to choose present needs and desires over future consequences of our actions. That seems to be the way it is with respect to climate change. As Kurt Vonnegut was fond of saying, “So it goes…”.

Sunday, September 4, 2011

Attacking the Messenger



The lay public’s trust in the work of scientists generally is eroded when there is evidence of fraud or another form of ethical lapse by any scientist or group of scientists. As I’ve written in Imperfect Oracle: The Epistemic and Moral Authority of Science, science’s capacity to exercise authority in the affairs of society is grounded on the presumption that scientists speak reliably and with good intent. This means that when scientists make claims based on their experimental or theoretical work, their representations of what they have found, and the conclusions based on them, are as full and true as they can make them.

For the most part, scientists share their work via talks and papers presented for the benefit of other scientists, in particular those working in the same or closely related fields. Individual contributions meld with others to form, over time, a more or less consensual understanding of what is going on in a given problem area. For that process to work individual scientist’s accounts must be as accurate and faithful to the findings of the research as possible. Futhermore, those individual accounts and claims must be subject to skeptical scrutiny by other scientists to ensure, insofar as possible, that they are correct. In this way, something that the philosopher and scientist Michael Polanyi called “scientific opinion” is formed. The epistemic authority of science as a voice in society’s affairs depends on a general acceptance of this idea. The process of vetting within the scientific community has the effect of producing stronger scientific accounts, but in addition it goes a long way toward rooting out fraud and unethical behaviors such as plagiarism.

A recent story of fraud within the field of chemistry may help to show how this works in at least one case. A former Columbia University graduate student, Beng├╝ Sezen, working under the tutelage of Professor Dalibor Sames, was found to have fabricated nearly the entirety of her doctoral thesis research. By the time her fraud was exposed, her thesis had been accepted, she had been awarded the Ph.D. degree and was the lead author on three research papers published in the Journal of the American Chemical Society, one of the most prestigious chemical journals in the world. Her thesis project dealt with a hot topic in organic chemistry. She seemed to have made some major breakthroughs in getting difficult reactions to occur in productive ways. She produced evidence in the form of spectra, analyses and so forth in support of her account. Sames, her thesis director, an up-and-coming young faculty member, was delighted with her work.

But there was a problem, uncovered by fellow graduate students in the Sames research group: no one could reproduce her results. Sames did not want to hear that Sezen’s work was suspect, and he was inclined to lay the blame for the failure to reproduce her work on the newer students. But Sezen’s labmates were more aware than Professor Sames that Sezen was committing fraud, and eventually they were able to convince Sames of that fact. A long and protracted investigation, involving a committee assembled by Columbia University, was undertaken. Because the research had been supported by federal research dollars, the Office of Research Integrity of the Department of Health and Human Services was involved, and eventually a notice was published in the Federal Register stating that she had falsified, fabricated and plagiarized research data in three papers and in her doctoral thesis. Her doctoral thesis was in due course revoked by Columbia University. Sames had to withdraw a total of six published research papers because no one could reproduce the work. His reputation has been severely damaged by the affair. For example, see the comments in the blog ChemBark.

Much has been written about this episode, but I wish to focus on what it might have to teach us about the trustworthiness of science. Sezen, a pathological liar, produced huge amounts of scientific garbage, and got away with it – for a time. She was extremely clever in forging data from other spectra, falsifying analytical results and so on. In the end, though, the fact that the work could not be reproduced, even though attempts were made by several graduate students, triggered the kind of closer look into her files, notebooks and other records that made the deceit completely evident. This case is small potatoes in the large scheme of things, but it serves to illustrate that fraud in science will be caught out eventually. Science does not owe its reliability to the fact that all individual scientists are error-proof or free of moral and ethical lapses. Rather, its organizational structure and ways of forming consensual scientific opinion lead to exposure of errors and fraudulent practices.

All of this has some relevance for the ill-considered criticisms of climate science by many who come to the discussion with biases against global warming based on partisan politics, economics or an ultraconservative aversion to anything that might suggest the need for collective, global actions. The likes of Rick Perry, Rush Limbaugh, Glen Beck, Newt Gingrich or Senator James Inhofe, collectively have no expert understanding of climate science. They also do not seem to understand how science actually works. This has not prevented them from declaring that global warming is some kind of scientific hoax. The community of scientists with expertise in one of the major areas of science, such as atmospheric science, oceanography , chemistry or meteorology, that bears in an important way on questions dealing with climate change, is huge, highly diverse and international in scope. Climate change is a very complex, difficult problem to attack. All these scientists working away at the part of the problem that falls within their expertise have to eventually pull together all the results and projections to produce a complete story. That has been done, and it continues to be done through international efforts as more and more evidence accumulates, and as the tools for making projections grow more reliable.

Given the best projections climate scientists can make there is plenty to be said about what we should or should not do. However, we cannot start talking about climate change with a childish pique that we don’t like what we are being told. The people I have mentioned above, and others like them, have nothing constructive to bring to the scientific aspects of the discussion, nor does it seem that they are interested in grown up considerations of climate policy. It’s sad that society’s responses to the challenges of climate change are held hostage to demagoguery, and self-interest. In time nature will deliver its verdict, and our grandkids can pass judgment on what we might have done.

Monday, August 29, 2011

Whose Moral Authority?






After a long hiatus I am back to blogging. I hope to keep up a steady rate of writing, on the order of one a week, perhaps more often. Since I last wrote a blog, a great deal has happened in the world of science and politics. What does not seem to have changed is the rate of clashes between a scientifically oriented view of the physical world and perspectives that see nature through the lenses of religiosity, a political perspective or some other form of anti-intellectual outlook. These alternative takes the physical world sometimes pay lip service to science, but deny science’s capacity to speak with authority on matters that present a challenge to preconceptions.

This seemingly perennial impasse is well illustrated by what Rick Perry, the governor of Texas, an announced candidate for the Republican nomination for US president in the 2012 election, had to say in response to questions from a woman and her son during a recent campaign stop in New Hampshire, as reported in the Huffington Post and elsewhere:
"How old do I think the earth is? You know what, I don't have any idea," said the Texas governor when asked about his position. "I know it's pretty old so it goes back a long long way. I'm not sure anybody actually knows completely and absolutely how long, how old the earth is." He went on to say that he regarded evolution as "a theory that's out there" and one that's "got some gaps in it." He added that in the Lone Star State both creationism and evolution are taught to students in public schools. He explained, "I figure you're smart enough to figure out which one is right."
The Texas Tribune expressed disquiet about Perry’s response to the evolution question, pointing out that the state of Texas has no specific curriculum entry for the teaching of creationism, and that in any case the Supreme Court in 1987 made it illegal to teach creationism in public schools, on the grounds that it would be equivalent to teaching religion. Perry may in fact have correctly stated what is actually taught in Texas schools; classroom practices are, after all, largely in the hands of the teachers. What is more important is what Perry’s responses reveal about his lack of basic scientific knowledge and his disregard for that lack in shaping his public persona. A further illustration of this is contained in remarks he made at a breakfast address before business leaders in New Hampshire, as reported in the Huffington Post and elsewhere. Asked about global warming he indicated that he did not believe in it, and referred to the idea as a scientific theory that has not been proven. He would not spend public funds in further research on the matter, or in mitigation of it: "I don't think from my perspective that I want to be engaged in spending that much money on still a scientific theory that has not been proven and from my perspective is more and more being put into question." He is also quoted as saying, "I think we're seeing almost weekly, or even daily, scientists that are coming forward and questioning the original idea that manmade global warming is what is causing the climate to change." Paul Krugman made several effective rebuttals to Perry’s absurd and false statements in a recent Op-ed. He attributes them to pandering to the no-nothing branch of the Republican party. However, as Richard Cohen wrote in the Washington Post, Perry may be pushing his luck on this topic. While mitigation of climate change through governmental actions may be a losing battle for those who want strong global responses to the threat, the idea that global warming exists is one of those memes that has gone viral, as it were. Outside a narrowing range of public opinion, it is becoming decidedly uncool to maintain that global warming is a myth.

To judge from the public record, Rick Perry’s brain is the domicile of many crazy ideas on a variety of subjects. We could search long and hard to uncover just what sources of authority he draws upon in arriving at his worldview, but there is little point in doing that. More importantly, Perry is not just any ignoramus; he’s a public figure with a strong record of running for elective office, who is now receiving a lot of attention on the national stage. A recent Texan predecessor, George W, spoke in a similar style of mangled syntax and lack of understanding of the history and operation of the physical world, and look where he ended up! What matters for the public good is that Perry’s misstatements about nature and the world of science, fitted to his ultraconservative ideology and the interests of his backers, lead to false claims being presented, for the moment at least, to large audiences . To the extent that Perry is seen as a viable candidate his positions on issues that should be discussed and decided upon with consideration for their scientific basis do matter.

Within a limited sphere there is room for optimism for a more influential role for science in forming public policy and governmental action. The Obama administration has been more progressive than its predecessor in promoting science and technology in both the areas of human resources and industrial R and D. For example, a big bet is being made on development and manufacture of advanced batteries, as reported recently in the New York Times. But at a deeper level, a real shift in the attitudes of ordinary citizens toward a rational scientific outlook, and away from reliance on superstition and demagoguery, eludes us. How could this be brought about? I’m sure that an answer is out there awaiting discovery. It may require capitalizing in some as-yet unrealized way on the ever-increasing presence of social networking and the sources of information that feed it. Whatever their origins and channels of delivery, society needs pervasive and reliable sources of epistemic and moral authority in matters regarding the natural world as effective alternatives to the narrow-minded, ultraconservative rhetoric that seems to dominate contemporary political discourse. In the contests for people’s hearts and minds science is not doing so well.

Paul Krugman ends his Op-ed piece as follows: “ [T]he odds are that one of these years the world’s greatest nation will find itself ruled by a party that is aggressively anti-science, indeed anti-knowledge. And, in a time of severe challenges — environmental, economic, and more — that’s a terrifying prospect.” That may seem a bit overwrought, but for those who strive for a society in which rational thought governs decision-making, it is also a call to greater participation. Whose moral authority will govern?

Monday, December 21, 2009

Doing science in a greenhouse


The recent furor surrounding the hacked e-mails from the Climate Research Unit (CRU) at East Anglia University has died down a good bit, but the effects of it will reverberate for a long time The e-mails reveal a good bit of small-minded belligerence toward some scientists whose views depart from the consensus position, and speak of excluding some of their work. The director of CRU, Phil Jones, has stepped down pending an investigation of the episode. Pennsylvania State University said it would review the work of Michael Mann, a faculty member cited prominently in the e-mail messages, to assure that it meets proper academic standards. Climate change skeptics have seized upon the disclosures as demonstration of what they have been saying all along, that the science behind the claimed anthropogenic changes to climate is dubious at best. Republicans in Congress are calling for investigations into the work of US scientists any way connected, inasmuch as they are likely to be supported by federal funds.

What can this episode teach us about the nature of scientific authority? Clearly the authority of many scientists identified in the e-mails has been substantially weakened, and, by association, that of the climate science community more generally. Analysis of this particular case can help us understand more clearly the boundaries between science and other social sectors, and point to how scientists should behave to sustain science’s proper societal roles (See Steven Shapin’s excellent essay on this subject, and the discussion in Imperfect Oracle).

Michael Gerson wrote in the Washington Post on December 11 about the melding of science and politics. In the interests of advancing the case for urgent responses to the threats represented by climate change, some prominent climate scientists “..appear to exaggerate their public certainty on disputed issues, shade the presentation of information for political effect, tamper with the peer-review process, resist reasonable requests for supporting data ..” He speaks of the insularity of the climate science community: “Climate scientists are clearly accustomed to deference. Theirs is a community coddled by global elites, extensively funded by governments, celebrated by Hollywood and honored with international prizes. But outside the Copenhagen bubble, the field of climate science is deep in a crisis of professional credibility, which many scientists seem too insular to recognize.” Gerson is not a climate change skeptic. His concern is that scientific objectivity seems to have been compromised by a drive for political and economic change: “But without trust in disinterested, scientific judgments on climate, most non-scientists will resist costly, speculative, legislative actions. When the experts become advocates, no one believes the experts or listens to the advocates.” He concludes that the climate scientists involved in the episode have diminished the authority of science more effectively than anyone else could have.

But Gerson’s position borders on saying that scientists’ expert authority is compromised whenever they move beyond the boundaries of their expert, or epistemic, authority to argue for what should be done in a given situation, as opposed to what is simply the case. In fact, there is a hierarchy of positions involved. At the first level the scientist is an expert, and exercises epistemic authority by reporting as objectively as possible on the scientific results. In the present case, climate scientists might offer expert opinions on the potential for climate change based on vast amounts of data accumulated on various aspects of the climate, and with the aid of extensively tested computer modeling of what future climate will look like given particular scenarios of fossil fuel use. If those opinions are a realistic representation of what the science community holds to be the case, we have a straightforward example of the exercise of epistemic authority. Beyond this a scientist can exercise moral authority, by moving beyond offering an expert scientific opinion to advise that a particular course of action be taken; in the present instance, to advise that certain policies should be established to mitigate the harmful effects of climate change. This effort to exercise moral authority presupposes the epistemic authority of the scientist. The scientist’s expertise plays a role, but in the broadest sense of making a moral judgment the scientist is no better positioned than anyone else in arguing for what actions should or should not be taken. A non-scientist acquainted with the results of the scientific studies might argue that, assuming a doubling of the carbon dioxide content of the atmosphere will result in an increase in the Earth’s surface temperature sufficient to cause much human travail, we should stop burning fossil fuels quickly as possible. In advancing the same argument, a climate scientist's view should not count for more than the non-scientist’s, since both are premised on the same scientific considerations. It's not that the scientist’s expert authority has been weakened, it is simply not the driving influence; in making the moral judgment the science is taken as a given, equally available to both scientist and non-scientist. Beyond this, the scientist and non-scientist alike can move to active advocacy in the public domain for the particular actions that were advised in the exercise of moral authority. In moving into this kind of advocacy, the scientist surrenders her credentials as a scientist; those have already been cashed out.

This of course all seems quite reasonable in the abstract, but when the topic is as huge, urgent and plagued with manifold complexities as climate change, distinctions become blurred. The differences between these different stances with respect to an issue of such wide social importance are not sufficiently appreciated, particularly by scientists. There is nothing inherently wrong in scientists getting caught up in political advocacy for causes that grow out of their scientific work. When they do so, however, they must reconcile themselves to the loss of much of their scientific expert and moral authority. When the arguments are flying back and forth as to what should be done, advocacy for particular courses of action is already premised on knowledge that is taken as a given. If the scientific basis for the argument is contested, we are back at the stage of shoring up expert authority. In the case of climate change, Senator James Inhofe, Glenn Beck and their ilk keep wanting to return the argument to that first stage. It has been tempting for climate scientists to depart from norms of objectivity and disinterestedness in the interest of protecting and enhancing their epistemic authority. But doing so has proven embarrassing for some, and damaging for science’s image as a reliable, trustworthy source of knowledge. Disagreements within the climate science community over data interpretations, adequacy of the models and the reality of human effects on climate are being thrashed out in a glass house. A lot of people are watching; science’s epistemic authority is being determined by what non-scientists can see of how science moves toward increasingly reliable knowledge. Climate scientists can help keep the focus where it should be by not providing further unfortunate diversions.

Saturday, December 12, 2009

The costs of fossil energy



We’ve known for a long time that the energy we need to keep society running costs us more than just the market price. There is also the price of repairing damage wreaked upon the environment and collateral impairments to human health. Think, for example of coal, the largest single source of energy for generation of electrical power. Coal mining typically makes a sorry mess of the environment. To get at the coal the terrain is ripped up, so pristine countryside is denuded. The residues left exposed to the weather leach out chemicals that change the acidities of streams and lakes, killing fish, often poisoning wildlife and rendering the water unfit for human consumption. As though that were not damage enough, the coal that is combusted in the power plants is contaminated with trace metals such as mercury. These find their way into the gas plumes from the plants to create health problems for those who live within a large radius. The sulfur in the coal is emitted as sulfur dioxide, which adds to the acidity of the atmosphere and is a health hazard in its own right. But the coal industry is very powerful; it can afford ads that reassure you that we are a safer and more prosperous nation because we can rely on coal as our very own energy source.

We are soothed even more by ads that claim that natural gas is a huge, clean source of energy, one that will serve us well for decades to come. It certainly burns more cleanly than coal, and may add less greenhouse gas to the environment than coal per unit of derived energy. But there seems always to be a dark side to each of these energy types. A recent article in the New York Times reinforces what we have been learning from other sources: that new technologies for freeing up natural gas in shale formations, called hydraulic fracturing, cause disturbances to the underlying strata that end up compromising water supplies vital to those who live in the environs. It can get pretty bad; for example, wells that are sufficiently contaminated with methane that they explode on contact with an igniting source. Furthermore, the water is also polluted with toxic chemicals used in the fracturing process.

Well, then, how about those tar sands up in Alberta, a huge and largely untapped source of fossil fuel energy? To learn more about the costs, environmental and otherwise, of extracting useful energy from the sands, read Elizabeth Kolbert’s 2007 report in the New Yorker magazine. What is being done to the environment in that quest for yet another source of fossil energy can make one ill. I could go on with more stories of our desperate quest for fossil fuels, such as deep drilling on the ocean floor; incredible technologies employed in ever riskier attempts to obtain fossil fuels. Every success, however limited, and at whatever price in terms of human health and environmental damage, helps lull us into thinking that we needn’t make special efforts to develop alternative sources of energy – solar, wind, new battery technologies, and yes, nuclear energy - that hold the promise of releasing us from our dependence on fossil fuels.

All of this is bears on the intense discussions presently being waged over the reality and extent of climate change. As Thomas Friedman recently pointed out, the details of the climate change debate are really not material to the larger issue of making ourselves less dependent on fossil fuels for the health of our economy and the prospects for a more livable world. Humankind has somehow to negotiate a very difficult transition in the decades ahead: creating a world society that is more balanced in terms of living standards, living more efficiently in terms of resource utilization, and bringing the human population to equilibrium at a number that the planet can sustain. Shouldn’t we in the United States be leading the way?

Saturday, December 5, 2009

Science with its pants down


Because the consequences of a human contribution to climate change are huge, scientific research that could shed light on this question is very important, and has risen to high visibility all over the world. Thus it has come to pass that a scandal of sorts in the world of climate science, referred to by some as “climategate”, has drawn a lot of attention.

I need not rehearse here the saga of the past couple of decades of intense debate over the question of whether humans are causing climate change. The implications for the workings of modern society are enormous. If it were the case that fossil fuel emissions are causing an increase in the temperature of the planet, and if that increase has the potential to cause disruption of society at many levels, a world-wide effort to mitigate that increase would be called for. We have had a succession of reports from the Intergovernmental Panel on Climate Change (IPCC), each presumably updating and improving upon its predecessor, that point to a likely increase in global temperature over the next 50 to 100 years. The predictions point to alarming changes in weather pattern s, and a potentially disastrous rise in sea level, along with a host of other changes that would require great adjustments in human society. So we are coming up to the Copenhagan conference, at which the nations of the world are once again under great moral pressure to respond to this threat. The costs of effective mitigation will run into the trillions of dollars.

On November 20 some files and e-mails originating in the Climate Research Unit of East Anglia University were made available publicly, by whom or by what means I don’t know. For those who have read the files and dug into some of the background, what they reveal is not a pretty story. Meagan McCardle summarized some of her conclusions and reactions in Atlantic magazine on December 1. What emerges from the discussions of this episode is that influential climate scientists at this very prominent voice of expertise on climate change appear to have behaved badly in several respects. They exercised undue power over the peer review process on papers dealing with climate change, and thus were able to stifle work that did not meet their well baked-in ideas of what is happening in the field. Here is a quote from one of the e-mails uncovered:
“I can't see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow - even if we have to redefine what the peer-review literature is !”

An even more serious problem has to do with the quality of much of the historical data on which the modeling studies depend. Climate models are tested in part by their capacity to produce temperature and other trends that match the historical data. It now emerges that the original data sets are nowhere to be found! The problem is that many of the older data have been adjusted for one reason or another over the years, by persons unknown, and for reasons that were not well documented. Much of the original computer code is formatted in computer languages no longer in use, and backing out the original data is maddeningly difficult if not impossible. These data are the source of what eventually becomes an estimate of the global temperature. So we have the situation that the historical record of the planet’s temperature is now in disarray, and may not even exist!

This episode is very distressing to me as it is to all who want to see science respected as a reliable and truthful source of knowledge of the world. I’ve written in Imperfect Oracle of the ingredients that make for science’s epistemic authority. I won’t recite all that here, but clearly truthfulness and a disinterested approach to one’s work are key ingredients. However, aside from what appear to be serious lapses from professional ethical standards, something else about this case strikes me as especially interesting. The reactions to this story would have one imagine that that original historical record of the global temperature is somehow sort of gold-plated scientific data, the true story of the planet’s temperature over the past 150 years. I believe that to be false. At best, much of that record is quite unreliable and subject to uncertainties that are much larger than the variations that are being talked about.

I wrote about the concept of global temperature in a book published in 2003, Making Truth: Metaphor in Science, (see pages 163-165). As I pointed out, there is no physical thing that corresponds to the global surface temperature, or at least there has not been to this point. Measuring the earth’s temperature is not like sticking a thermometer under the tongue and getting a measurement that is satisfactorily representative of the temperature regime throughout the entire body. When the tongue thermometer registers a change of a degree or two from the normal, the fact of that temperature change is evident in the way the person feels: feverish. There is no analog to the under-the-tongue thermometer in measuring the surface temperature of the planet. Until the advent of satellite measurements which only now are becoming well enough standardized to serve as a reliable measure, climatologists relied upon a patchwork of measurements non-uniformly covering the planet’s surface, many of them individually unreliable, which was then somehow put together to give a number we call the global temperature. In truth, it is a sad fact that this idea of a reliable global temperature has been sold by climatologists with scarcely any acknowledgement of how sketchy it really is.

It is important to note that the absence of a reliable historical record of the planet’s surface temperature does not render impotent the idea that the planet is warming. Suppose you had an unreliable thermometer for measuring your body temperature. Even if the device did not give you a reliable measurement, you would know if you had a significant fever, right? In the same way, it is evident from what we see occurring in nature that the planet is growing warmer: disappearing arctic ice, glacial melting, shifts in weather patterns that clearly betoken warming in both hemispheres. The big issue, however, is whether and to what degree this warming is due to human activity. This is where climate modeling comes in. If they are sufficiently complete and self-consistent, the very large, complex computational programs that the climatologists have produced should be able to tell us how much change in surface temperature could be accounted for by greenhouse gases added by human activity. But are the models sufficiently realistic ? One way to test this is to see whether they reproduce historical climate change. Also, though I am unsure about this point, the programs may need the historical data for some aspects of the computations. But if we don’t have a reliable, sufficiently complete historical record…well, climate science has a credibility problem.

This episode has dealt a blow to science’s epistemic authority, and to its moral authority as well.

Wednesday, November 25, 2009

Update on Nebraska

In my most recent blog I wrote about the possibility that the Board of Regents of the University of Nebraska might vote in a policy that would place severe restrictions on the range of embryonic stem cell research that could be conducted within the university. According to a news item published on November 25 by the American Association for the Advancement of Science, the board did not have sufficient votes to carry the policy forward:

“University of Nebraska Votes Against Changing Policies on Stem Cell Research. The University of Nebraska's Board of Regents voted against changing its existing policy governing research on embryonic stem cells, a move that will allow the university to continue research on stem cell lines in accordance with the new NIH guidelines. A resolution was proposed that would have restricted the campus policy to allow only research on the cell lines that were approved under the 2001 policy issued by former President Bush. The eight-member Board voted 4-4, and since a majority of votes is required to pass a resolution, the proposed change was defeated. AAAS issued a letter to the University's President and Board of Regents emphasizing its support for human embryonic stem cell research conducted with appropriate ethical guidelines.”

The Board's decision is, I suppose, something of a victory, but the closeness of the vote demonstrates how divided the Board was on the matter. I think of it as more of a reprieve than a victory. Those who would like to force their constructions of what is right and wrong on the rest of us will not give up on their efforts, not in Nebraska or elsewhere. The only defense for those who value intellectual freedom, and an open, pluralistic society in which to practice it, is to keep working on communicating their core values as vigorously as possible. If we want free choice within reasonable societally accepted boundaries, there is no real alternative to pushing back against extremism while engaging with others who may have differing viewpoints but seek a satisfying framework for making social policy.