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Confusing Future Presidents, Part 1

We all bemoan the low level of scientific discourse in politics. So one might have high hopes for a course, textbook, and book for the general public all titled Physics For Future Presidents as something that might help educate today’s students and hence tomorrow’s leaders to be able to deal with basic science.

How dismaying then that the book is full of opinions and misinformation, not science, and that what is being taught would certainly mislead Future Presidents on issues such as terrorism, climate, and electric cars.

Confusingly, the textbook and the general public book have the same title, though the general public adds the subtitle The Science Behind the Headlines. A more appropriate title for the books might have been Confusing Future Presidents: My Biased Opinions.

My first encounter with the textbook Physics For Future Presidents was in 2006, when it was available on the web. As an example, the author tried to demonstrate that electric cars were impractical, and that in particular that the claims being made by Tesla Motors for their forthcoming Roadster were hype, easily refuted by basic calculations as taught in his course. For example, he estimated the cost, mass, and volume of the battery pack. The cost was said to be $922,000 (9 — the sales price), the mass 6,831 pounds (2.5 — the mass of the car), and that the volume to be 390 gallons. Basic sanity checking of the calculation was called for, but not done. The actual calculations were off by factors of 46, 9.7, and 12.7 from reasonable estimates that could have been made at the time. No sanity checking was done.

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Professor Richard A. Muller’s general public book is now in print. Given the earlier encounter, I shuddered at the thought of what our Future Presidents are now being taught, so I had a look at the print edition at my local bookstore. This also prodded me to take another look at the textbook, some chapters of which are still online, including the chapter on climate. Part 1 of this review will look first at the books’ handling of climate science. Part 2 will look at the solution chapters, and other topics.

Climate

The general reader book sets high goals for itself in the introduction:

Equally important to understanding the physics of modern life is unlearning the things that you may think are true but aren’t. … This book covers advanced physics, the stuff that world leaders need to know. … When you understand the underlying principles, the physics, you need never be intimidated by high tech. … This is the physics that you need to know to be a world leader. The rest is up to you.

The Evidence chapter of the global warming section of the general public book has this strong statement:

Physicists, by tradition, have a more stringent standard than the courts: if you get caught exaggerating, distorting, or cherry picking, your scientific reputation is damaged if not destroyed.

It goes without saying that the textbook should have similar goals, though all it claims is “I will not to exaggerate, either way.” But then both books go on to exaggerate, distort, and cherry pick, making a mockery of the words above.

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Let’s look first at the textbook chapter on Climate. Professor Muller does tell his students that global warming is real, but gives only a small introduction to the material, and then spends most of the chapter attacking what he sees as the exaggeration of global warming activists, such as Al Gore. The student is left with a confusing message. They have little more than the author’s and IPCC’s statements that global warming is real and then lots of reasons to to think global warming science is confusing and uncertain. Is this what Future Presidents should know about global warming? And where is the Science? Teaching Science is not reciting cherry-picked facts you want students to know, it is about giving them them concepts that can be applied in diverse situations.

The textbook chapter never explains the impacts that global warming is predicted to have (e.g. drought, extreme weather), or the other things a Future President should know about global warming, such as the difference between different greenhouse pollutants.

Professor Muller’s attacks as climate hyperbole topics such as hurricane Katrina, tornadoes, Alaska temperatures, Antarctica’s differences from climate models, and paleoclimate correlations. Both books include claims that hurricane and tornado frequency are down, but never mention National Climate Data Center’s Climate Extremes Index. Apparently only data that discredits Al Gore is worthy of mention.

On paleoclimate, he writes about the chart showing CO2 and temperature:

In his movie, Al Gore gives the impression that this verifies that CO2 causes climate change. In fact, even though that is the conclusion that most people watching the movie come away with, he never actually says that. He says that the situation is “complicated.” And indeed it is. He summarizes the plot by saying that every time there is a lot of carbon dioxide, it is warm, and whenever the carbon dioxide is low, it is cool.

But most geophysicists believe that it is the temperature that is causing the CO2 to change, not the other way around. Most of the CO2 in the biosphere is actually dissolved in ocean water. When the water warms, the CO2 is driven out; gas doesn’t dissolve as well in warmer water. The fact that warming is causing the CO2 change is verified by other measurements that indicate that the CO2 changes lag the temperature changes by about 800 years. In other words, the temperature changes first, and then it takes 800 years for the CO2 to finish coming out of the ocean. That’s a reasonable number, because we know that deep ocean water takes about that long before it works its way to the surface, where the CO2 can escape.

Something else in the plot suggests that the CO2 is a result of warming, not the other way around. Look at the recent CO2 rise, at the right side of the plot. The recent increase is about as much as the increases at the ends of the ice ages. If the CO2 were causing the warming, we would expect to see a 10 to 15°F warming, not the 1 to 2°F warming that we have actually experienced.

Some scientists disagree, and think CO2 may have indeed been responsible. The situation is “complicated”. Perhaps the 800-year lag has been misinterpreted. There really is a reasonable controversy here.

Professor Muller turns the simple and important notion of positive feedback into a controversy by presuming that the mechanism is one or the other rather than both. In the paleoclimate record it is clear that greenhouse gases can drive temperature (e.g. this is a leading hypothesis for the Paleocene-Eocene Thermal Maximum), and it is likewise fairly clear that temperature can drive CO2. This bidirectional effect is the result of positive feedback: temperature affects CO2, and CO2 affects temperature with the net result that a small change in either results in a larger total change (an amplification). The textbook turns a learning opportunity into an attack on Al Gore for pointing out correlation.

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In the general public book he adds his opinion of the “hockey stick” controversy, without giving any indication that the hockey stick has been for the most part independently validated. For example, he writes,

Then came a shock. Canadians Stephen McIntyre and Ross McKitrick uncovered a fundamental mathematical flaw in the computer program used to produce Mann’s hockey stick result. In this original publications of the hockey stick, Mann said he had used a standard method known as principal component analysis, or PCA, to find the dominant features in a set of more than 70 different climate records. But it wasn’t so. McIntyre and McKitrick obtained a key part of the computer program that Mann had used, and they found serious problems. Not only did the program not do conventional PCA, but it handled data normalization in a way that can only be described as wrong.

This is a very one-sided version of the story, which is handled far more evenly at Wikipedia. At best the above is cherry-picking. It could be said to be distortion and exaggeration as well. Professor Muller also never hints that the hockey stick data is supported by independent analysis besides Mann’s, which would be very relevant to his readers. Nor is there any indication that Mann’s analysis was on the cutting edge of temperature reconstruction methodologies. The National Academy of Sciences released a report on the controversy on 22 June 2006. In the preface the report chair explained the scientific process at work here:

Science is a process of exploration of ideas — hypotheses are proposed and research is conducted to investigate. Other scientists work on the issue, producing supporting or negating evidence, and each hypothesis either survives for another round, evolves into other ideas, or is proven false and rejected. In the case of the hockey stick, the scientific process has proceeded for the last few years with many researchers testing and debating the results. Critics of the original papers have argued that the statistical methods were flawed, that the choice of data was biased, and that the data and procedures used were not shared so others could verify the work. This report is an opportunity to examine the strengths and limitations of surface temperature reconstructions and the role that they play in improving our understanding of climate. The reconstruction produced by Dr. Mann and his colleagues was just one step in a long process of research, and it is not (as sometimes presented) a clinching argument for anthropogenic global warming, but rather one of many independent lines of research on global climate change.

The whole purpose of Mann et al’s 1998 work was to propose methods, try them, report results, and begin a dialog with other scientists. That dialog results in better data and methods. The NAS report concluded that while there were issues with the way PCA was used in 1998, the results were confirmed by further work:

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and he retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.

In contrast, Professor Muller wrote about the NAS report,

In the end, there was nothing new left in Mann’s papers that the National Academy supported, other than the idea of using principal component analysis was, in principle, a good one.

This is a distortion of the NAS report. Nature wrote about the NAS report,

In its report, released on 22 June, the NAS committee more-or-less endorses the work behind the graph. But it criticizes the way that the plot was used to publicize climate-change concerns.

It is not my purpose here to settle the hockey stick issue (read the Wikipedia article for details), but rather to illustrate Professor Muller’s one-side approach to it. Mann updated his reconstruction of past temperatures with more data in 2003, and updated it again in 2008, as would be expected by the scientific process. To attack only the first work in a new area without referring to independent and subsequent work is cherry picking. The reader is left poorer in understanding by reading Professor Muller’s treatment of the subject.

In Part 2, this book review will turn to the general reader books solutions to global warming, and look at other chapters that illustrate the same sort of cherry-picking seen in the climate science.

— Earl K.