Dealing with Climate Change: Getting There from Here

Engineers are people of action, not just words.  But even if we believe what we are often told about climate change, it's not at all clear what we should do about it.

Last week, I attended a meeting at which a highly credentialed professional meteorologist outlined the history of the science of climate change from the nineteenth century to the present.  Prof. Andrew Dessler of Texas A&M's Department of Atmospheric Sciences described how as long ago as the 1890s, Swedish scientist Svante Arrhenius calculated that the small concentration of carbon dioxide in the atmosphere (then around 300 parts per million) had a disproportionate effect on the earth's temperature.  Regular monitoring of this concentration began in the 1950s, and by then it was clearly understood that more carbon dioxide means higher temperatures.  Dr. Dessler said that for at least fifty years, there has been a consensus that the present human-caused increase in carbon dioxide in the air will eventually lead to a rise in global average temperatures of "a few degrees C." 

So far I was with him.  Other things being equal (which they never are), more greenhouse gases in the air (of which carbon dioxide is one) means the planet gets warmer.  But then he started talking about cigarette smoking, and how the tobacco industry mounted a cynical disinformation campaign in the 1960s against the overwhelming evidence that smoking caused lung cancer and heart disease.  Because it took about forty years for the scientific truth to change public policies (you began to see smoke-free campuses and workplaces only about ten years ago), Dr. Dessler thinks it may take that long for the U. S. to get serious about global warming.  Personally, I think it will take longer than that, because the two cases are more different than they are similar.

As someone else in the audience pointed out, smoking has highly specific individual consequences.  As long ago as 1964, anyone who read a newspaper knew that by smoking, you made it a lot more likely that you would die early and fast, the way my father died of lung cancer at 57 only a year after he was diagnosed.  If driving a Humvee increased your personal chances of having your own house wrecked by a tornado by the same degree as smoking increases your chances of causing lung cancer, what would happen?  Well, for one thing, Humvee owners would have a lot of trouble getting home insurance.  And sales of Humvees would fall.

But in contrast to the smoking-cancer tie-in, the actions that contribute to climate change, and the possible (I emphasize "possible") consequences, are about as far removed as you can get and still stay on the same planet.  From what little I know about the matter, it appears that the most widespread and likely consequence of letting the earth's average temperature rise a few degrees Celsius is that a lot of ice will melt, water will expand, and the ocean's average levels will rise.  Let's leave aside all the other stuff—species extinction, storms, and other changes in weather patterns—and concentrate on just that one thing.

About 44% of the world's population in 2010 lived within 150 km (94 miles) of the sea.  And many of the world's most populous cities are coastal ones, or so close to the coast that a significant rise in ocean level would cause them major problems.  Now if all the ice in Antarctica melted, the ocean's level would rise some 61 meters (200 feet).  So in that case, good-bye Hong Kong, New York, and Florida.  But to my knowledge, no serious scientist has proposed that the entire ice sheet covering Antarctica is going to melt because of human-induced climate change.  So the fact is that you have a range of estimates of how much the oceans will rise, but all of them are much less than 61 meters.  They may be well-educated estimates, but that's all they are—estimates.

So instead of a single increased chance that you, individually, will suffer about the most serious consequence you can encounter—death—as a result of your individual actions, your individual motivation to do something about climate change is that somebody, somewhere, possibly but not certainly near a coastline, might eventually have to move or suffer an increased chance of getting flooded out in a storm.  And that person might be you, but not for another few decades, anyway.  And even if you become a hyper-climate-conscious zero-carbon-footprint fanatic, your solitary actions will be fruitless unless billions of people all across the world do likewise, or at least move in that direction.

Personal versus impersonal, individual versus transnational, death versus some fuzzy probabilistic consequence for many people you will never meet—at the point of political action, the analogy between smoking and burning fossil fuels collapses.  There is also the little matter of the difference in economic importance of the two industries in question.  If the entire tobacco industry vanished tomorrow, life could go on more or less normally for most of us, but if the entire fossil-fuel industry vanished tomorrow, a large number of us would die in a matter of weeks for lack of basic necessities.  That is a big downside cost to the proposal to something about climate change fast.

Prof. Dessler sees a global carbon tax as the way forward.  He thinks if the U. S. slapped a big carbon tax on imports, that the rest of the world would fall in line and come along quietly.  A global tax high enough to put significant brakes on fossil fuel consumption now would likely do something similar to what the Smoot-Hawley Tariff of 1930 did.  Most economists believe that those extremely high U. S. tariffs contributed significantly to the worldwide depression of the 1930s, and punitive carbon taxes imposed on countries that don't get in line with reduction in fossil-fuel use would probably trigger a global depression that would make the 1930s one look like a mild headache in comparison.

From an engineering point of view, achieving the goal of transitioning from a global economy based on fossil fuels to one in which fossil-fuel use is cut to a small fraction of its present rate is logically possible.  But achieving it in a way that is just and fair, and imposes hardships less than those otherwise suffered from whatever climate change would result, is an immensely challenging technical and political task, and would require a degree of coordination and cooperation that is unprecedented in world history. 

Maybe it will happen.  But if history is any guide, something really awful, and unequivocally attributable to climate change, will first have to happen worldwide, in order to create the political will to act.

Sources:  Prof. Andrew Dessler spoke at the Lone Star Historians of Science meeting at Texas A&M University on Apr. 11, 2014.  I referred to Charles Krauthammer's column on climate change carried by the Washington Post on Feb. 20, 2014 at http://www.washingtonpost.com/opinions/charles-krauthammer-the-myth-of-settled-science/2014/02/20/c1f8d994-9a75-11e3-b931-0204122c514b_story.html, and Daniel Yergin's history of climate change at http://danielyergin.com/history-of-climate-change/. 

The statistic about ocean levels and Antarctica is from http://science.howstuffworks.com/environmental/earth/geophysics/question473.htm.  And for how a qualified opponent of the conventional view of climate change, Prof. William Happer, was received at another professional meeting, see my blog "When Scientists Aren't Scientists" on Oct. 7, 2013.

A Riveting Story: The Titanic's 94-Year-Old Mystery Solved

The sinking of the White Star Line's luxury passenger liner Titanic on April 14, 1912 has got to be one of the most famous engineering failures in history. Everybody knows the story: how the ship ran full speed into an iceberg despite warnings relayed by the then-new wireless, and sank less than three hours later with the loss of over 1500 lives. Since the discovery of the wreck in 1985, researchers have been able to recover hundreds of artifacts and subject them to modern forensic analyses. Two of these researchers—metallurgical experts Jennifer Hooper McCarty and Tim Foecke—have written a book about their discoveries. What Really Sank the Titanic clears up a long-standing mystery about the tragedy and points the finger of blame in a surprising direction.

Boards of inquiry held immediately after the disaster obtained enough information from survivors to piece together the following story. At about 11:40 PM, as the Titanic moved at about 22 knots through a near-freezing sea "as smooth as glass," lookouts spotted an iceberg in the path of the ship. The steersman had just begun to turn the bow to port when the berg scraped along the starboard side of the ship, making a long-lasting noise that was described variously as tearing, jarring, or ripping. Although the ship's six watertight compartments were immediately sealed when it was discovered that water was coming in, there were enough holes in different parts of the hull that eventually all six compartments filled up, and the ship sank. The ship's designer, Edward Wilding, said at one inquiry that a long, narrow series of slit-like openings about two hundred feet long and only an inch or so wide would have accounted for the fashion and speed with which the ship foundered. But since steel is much harder than iceberg ice, he could not explain how such openings could have occurred. There the mystery lay at the bottom of the North Atlantic for over eighty years, until salvage expeditions began to bring pieces to the surface.

In a decade-long investigation, McCarty and Foecke, respectively graduate student at Johns Hopkins University and staff member at the Gaithersburg, Maryland office of the National Institute of Standards and Technology, obtained samples of the Titanic's hull, which consisted of large steel plates held together by rivets (electric-arc welding was not to become the standard steel-fabrication method until World War II). McCarty's archival research in England revealed that Harland & Wolff, the ship's Belfast builders, used two kinds of rivets: the more modern machine-formed steel rivets for the central part of the ship, and the old-fashioned hand-formed wrought-iron type for the stern and bow sections, where much of the collision impact probably occurred.

The making and installing of wrought-iron rivets was largely a manual operation. The Titanic needed over three million rivets in all, and this huge demand led flocks of entrepreneurial ironmakers to enter the field. The hand-stirred "puddling" process then used to make wrought iron from ore required strong and highly experienced workers, of which there were not enough in 1912. So it turned out that Harland & Wolff bought wrought iron from a wide variety of suppliers, some of whom were much less experienced than others. McCarty and Foecke have proof of this in the form of long, stringy slag inclusions they found in some of the recovered rivets. These inclusions tended to make wrought iron, an already a less satisfactory material than steel, even weaker.

Why weren't steel rivets used throughout? Besides reasons of cost, steel rivets had to be formed with hydraulic riveters—large U-shaped steel machines upwards of six feet high that had to be laboriously positioned on either side of the plate to be riveted. Then the rivet, shaped much like a blunt round-headed nail, would be heated, inserted into its hole through the two overlapping hull plates to be joined, and squeezed between the jaws of the riveter. This squeezing formed heads on both ends, and as the rivet cooled, the resulting shrinkage provided tension that held the two steel hull plates together in a watertight joint.

At least, that was how it was supposed to work. The problem was there was not enough room in the bow and stern areas to maneuver the hydraulic riveter. So the builders resorted in those areas to the older hand-forming way of riveting, which couldn't use steel rivets because of reasons to do with the different ways steel and iron cool. Wrought iron was more forgiving to the delays and variations involved when a boy tossed a red-hot rivet from a portable stove to the rivet gang, which placed it in its hole and pounded it in by hand.

When the Titanic embarked on her maiden voyage on April 10, 1912, her bow hull plates were held together by wrought-iron rivets. The iron itself had probably never undergone any systematic quality testing, and the only quality tests done on the finished riveting job was a hurried hammer tap by an inspector, who listened to the sound it made. All this inspection could detect was loose rivets, not those made from defective wrought iron.

Then came the iceberg. While ice itself will crumble if forced against solid steel, the typical iceberg was a lot heavier than the Titanic. So in a glancing collision, the iceberg exerted tremendous localized force against only a few hull plates at a time. While even poorly-made rivets can withstand the mainly sideways stress that uniform pressure causes (e. g. hydraulic pressure on a water tank or a ship's hull), some of the forces that the iceberg caused tended to pull the hull plates apart, causing tensile stress. And the researchers found that wrought-iron rivets made of bad iron with lots of slag inclusions pop their heads off much more easily than either steel rivets or wrought-iron rivets made with better material. Significantly, many of the steel plates recovered from the wreckage were missing their rivets altogether. And riveting is not a gracefully-degrading fastening method. Once one rivet in a row pops, the ones next to it get much higher stress and are likely to fail as well, leading to a kind of chain-reaction zipper effect.

That is exactly what McCarty and Foecke say must have happened as the iceberg bounced repeatedly along the side of the ship, popping rivets and opening up long, narrow slots between hull plates—exactly what designer Wilding said in 1912 must have happened, though he couldn't explain exactly how. The researchers also show in detail how a rival theory—one that says the cold Atlantic waters made the plates themselves brittle enough to shatter like glass—is full of holes, so to speak.

So the roots of the Titanic disaster prove to go in several directions: to the heedlessness of the captain who failed to slow down in a known field of icebergs, to the rulemakers who didn't require lifeboats for everybody, and, surprisingly, to little mom-and-pop wrought-iron puddling operations that sprang up all over the United Kingdom in response to increased demand for wrought iron. McCarty and Foecke conclude that if all the ship's rivets had been steel, the ship still might have sustained serious damage, but not so much as to sink it in less than three hours. Even a few hours longer afloat could have given time for nearby ships to arrive and save most or all the passengers. But that was not the way it happened.

Sources: What Really Sank the Titanic was published in 2008 by Citadel Press. I also thank my wife Pamela for her thoughtfulness in this birthday-gift selection.

Non-Lethal Weapons, Part I: Ray Gun or Ray Howitzer?

First, some housekeeping items. When I began this blog nearly a year ago, I hid behind a screen of anonymity because I was afraid of negative repercussions that might arise from incautious words I might write. Recently, eminent engineering ethics expert Steve Unger at Columbia University wrote me that he is thinking of starting a blog, and wanted to know why I didn't put my real name on mine. (He knows who I am because my emails all have a tag line with the blog's URL in it.) I thought about it and couldn't give him a good reason, so as of today my profile and the header show my real name. As always, comments are welcome. If you have sent me a comment and I haven't replied to you, it's because the blog machinery doesn't inform me of your email address. If you would like me to be able to contact you, send an email to kdstephan@txstate.edu at the same time you add a comment to this blog, and I'll be able to respond.

Now for the first-ever two-part series in this blog: non-lethal weapons. I thank George Michael Sherry of Fort Worth, Texas for bringing my attention to an Associated Press article that was carried on MSNBC on Jan. 25, 2007. According to this report, the ray gun of science-fiction legend has arrived. It takes the form of a truck that carries a kind of radar-antenna thing about fifteen feet high. Even if you're as far away as five hundred yards, the thing's beam can make you feel like you're on fire. No actual fire results, because the total amount of power involved is limited. A video clip shows a civilian—possibly a reporter—standing in a field at Moody Air Force Base outside Valdosta, Georgia. All of a sudden he jumps like a snake bit him, and starts to laugh, aware of how foolish he looks.

As a microwave engineer, I viewed these proceedings with decidedly mixed emotions. On the one hand, my pure-engineer side rejoiced to see some familiar old technology being used in a novel and possibly helpful way. The energy used—94-GHz millimeter waves—is something I have known about and done research with for years, although at a lower power level than what the military is using in the alleged ray gun. They have taken a high-power source—probably a vacuum tube of some kind—and focused the energy in a narrow beam that probably covers a few dozen yards' worth of people at a distance of 500 yards. Full disclosure requires me to say that about twenty years ago, I received some research funds from Raytheon Corporation, which built the unit used in these tests. The technology to do this has been around for years, if not decades, but perhaps the will to try this or the funding was lacking until now.

Before we get to the ethical issues, my pure-engineer side has some questions, though. I thought a ray gun was supposed to fit in your pocket. A more apt term for this thing is "ray howitzer," a howitzer being a piece of field artillery larger than a single man can conveniently carry. Not only does this gizmo require a large truck to haul it around (and probably a multi-kilowatt generator buzzing away somewhere), but because of fundamental physical laws, there is very little chance that they'll ever be able to make it much smaller than it is now. If they tried, the beam would spread out to where you'd be as likely to shoot yourself as anybody else nearby. And then there's the cost. The article didn't mention how many tax dollars the project used up, but unless vacuum-tube millimeter-wave technology has had some dramatic breakthroughs lately (and I haven't heard of any), you can bet that even in production-quantity runs this ray gun would set you back many hundreds of thousands a piece, if not more. And while a spokesperson for the military refused to comment on whether the rays would penetrate glass, I can say that without fear of contradiction, it depends. What I can say for sure is that even a thin sheet of metal such as aluminum foil will block the rays completely. While you might look silly walking around in an aluminum suit, you'd have no worries about being zapped by the millimeter-wave ray howitzer.

Now for the ethical questions. The issue of whether non-lethal weapons should be used at all is an interesting one, but there is not space here to give it justice. My main question in this area is, does the use of this device truly have no long-term health effects? Over the years there have been several studies that link exposure to high-power microwaves with the growth of cataracts in the eye. The prevalence of convenient and effective cataract surgery these days doesn't mean that we should quit worrying about giving people cataracts. It's a legitimate question whether exposure to just one "zap" from the ray howitzer could cause enough eye damage to lead to cataracts. That is a technical question for the appropriate experts, but I raise it here simply because it may not have been asked yet.

All things considered, I don't believe we have a lot to fear from people with ray guns roaming the streets and towns of America. I will be surprised if Raytheon or anybody else can make this technology cheaply enough for it to pose a threat to water cannons, tear gas, or other popular means of dispersing angry crowds. If my experience as a lecturer on microwave engineering is any guide, you could inspire a set of rioters with the same intense longing to be somewhere else that the ray howitzer inspires, by trying to teach them the Fourier transform that relates the size of the machine's dish to the size of the beam. And the lecturer would come a lot cheaper.

Sources: The ray gun article appeared on the MSNBC website at http://www.msnbc.msn.com/id/16794717/wid/11915829?GT1=8921. Information on the relation between cataracts and microwaves can be found at places such as the Communications Workers of America website (http://www.cwa-union.org/issues/osh/articles/page.jsp?itemID=27339127) and an index of research by professor of history Nicholas Steneck on the hazards of microwave radiation (http://myweb.cableone.net/mtilton/steneck.html). It appears that "normal" exposure to microwaves and radio-frequency radiation has few if any reproducible clinical effects, although many experts disagree on the conclusions that should be drawn from the abundance of research.