Sunday, July 22, 2012

Popular Basis of Political Authority | The Founders' Constitution

[Volume 1, Page 68]

CHAPTER 2 | Document 23

Thomas Jefferson to James Madison

6 Sept. 1789 Papers 15:392--97

I sit down to write to you without knowing by what occasion I shall send my letter. I do it because a subject comes into my head which I would wish to develope a little more than is practicable in the hurry of the moment of making up general dispatches.

The question Whether one generation of men has a right to bind another, seems never to have been started either on this or our side of the water. Yet it is a question of such consequences as not only to merit decision, but place also, among the fundamental principles of every government. The course of reflection in which we are immersed here on the elementary principles of society has presented this question to my mind; and that no such obligation can be so transmitted I think very capable of proof.--I set out on this ground, which I suppose to be self evident, that the earth belongs in usufruct to the living : that the dead have neither powers nor rights over it. The portion occupied by an individual ceases to be his when himself ceases to be, and reverts to the society. If the society has formed no rules for the appropriation of it's lands in severality, it will be taken by the first occupants. These will generally be the wife and children of the decedent. If they have formed rules of appropriation, those rules may give it to the wife and children, or to some one of them, or to the legatee of the deceased. So they may give it to his creditor. But the child, the legatee, or creditor takes it, not by any natural right, but by a law of the society of which they are members, and to which they are subject. Then no man can, by natural right, oblige the lands he occupied, or the persons who succeed him in that occupation, to the paiment of debts contracted by him. For if he could, he might, during his own life, eat up the usufruct of the lands for several generations to come, and then the lands would belong to the dead, and not to the living, which would be the reverse of our principle.

What is true of every member of the society individually, is true of them all collectively, since the rights of the whole can be no more than the sum of the rights of the individuals.--To keep our ideas clear when applying them to a multitude, let us suppose a whole generation of men to be born on the same day, to attain mature age on the same day, and to die on the same day, leaving a succeeding generation in the moment of attaining their mature age all together. Let the ripe age be supposed of 21. years, and their period of life 34. years more, that being the average term given by the bills of mortality to persons who have already attained 21. years of age. Each successive generation would, in this way, come on, and go off the stage at a fixed moment, as individuals do now. Then I say the earth belongs to each of these generations, during it's course, fully, and in their own right. The 2d. generation receives it clear of the debts and incumberances of the 1st. the 3d of the 2d. and so on. For if the 1st. could charge it with a debt, then the earth would belong to the dead and not the living generation. Then no generation can contract debts greater than may be paid during the course of it's own existence. At 21. years of age they may bind themselves and their lands for 34. years to come: at 22. for 33: at 23. for 32. and at 54. for one year only; because these are the terms of life which remain to them at those respective epochs.--But a material difference must be noted between the succession of an individual, and that of a whole generation. Individuals are parts only of a society, subject to the laws of the whole. These laws may appropriate the portion of land occupied by a decedent to his creditor rather than to any other, or to his child on condition he satisfies the creditor. But when a whole generation, that is, the whole society dies, as in the case we have supposed, and another generation or society succeeds, this forms a whole, and there is no superior who can give their territory to a third society, who may have lent money to their predecessors beyond their faculties of paying.

What is true of a generation all arriving to self-government on the same day, and dying all on the same day, is true of those in a constant course of decay and renewal, with this only difference. A generation coming in and going out entire, as in the first case, would have a right in the 1st. year of their self-dominion to contract a debt for 33. years, in the 10th. for 24. in the 20th. for 14. in the 30th. for 4. whereas generations, changing daily by daily deaths and births, have one constant term, beginning at the date of their contract, and ending when a majority of those of full age at that date shall be dead. The length of that term may be estimated from the tables of mortality, corrected by the circumstances of climate, occupation &c. peculiar to the country of the contractors. Take, for instance, the table of M. de Buffon wherein he states 23,994 deaths, and the ages at which they happened. Suppose a society in which 23,994 persons are born every year, and live to the ages stated in this table. The conditions of that society will be as follows. 1st. It will consist constantly of 617,703. persons of all ages. 21y. Of those living at any one [Volume 1, Page 69] instant of time, one half will be dead in 24. years 8. months. 3dly. 1[8],675 will arrive every year at the age of 21. years complete. 41y. It will constantly have 348,417 persons of all ages above 21. years. 5ly. And the half of those of 21. years and upwards living at any one instant of time will be dead in 18. years 8. months, or say 19. years as the nearest integral number. Then 19. years is the term beyond which neither the representatives of a nation, nor even the whole nation itself assembled, can validly extend a debt.

To render this conclusion palpable by example, suppose that Louis XIV. and XV. had contracted debts in the name of the French nation to the amount of 10,000 milliards of livres, and that the whole had been contracted in Genoa. The interest of this sum would be 500. milliards, which is said to be the whole rent roll or nett proceeds of the territory of France. Must the present generation of men have retired from the territory in which nature produced them, and ceded it to the Genoese creditors? No. They have the same rights over the soil on which they were produced, as the preceding generations had. They derive these rights not from their predecessors, but from nature. They then and their soil are by nature clear of the debts of their predecessors.

Again suppose Louis XV. and his cotemporary generation had said to the money-lenders of Genoa, give us money that we may eat, drink, and be merry in our day; and on condition you will demand no interest till the end of 19. years you shall then for ever after receive an annual interest of 125/8 per cent. The money is lent on these conditions, is divided among the living, eaten, drank, and squandered. Would the present generation be obliged to apply the produce of the earth and of their labour to replace their dissipations? Not at all.

I suppose that the recieved opinion, that the public debts of one generation devolve on the next, has been suggested by our seeing habitually in private life that he who succeeds to lands is required to pay the debts of his ancestor or testator: without considering that this requisition is municipal only, not moral; flowing from the will of the society, which has found it convenient to appropriate lands, become vacant by the death of their occupant, on the condition of a paiment of his debts: but that between society and society, or generation and generation, there is no municipal obligation, no umpire but the law of nature. We seem not to have percieved that, by the law of nature, one generation is to another as one independant nation to another.

The interest of the national debt of France being in fact but a two thousandth part of it's rent roll, the paiment of it is practicable enough: and so becomes a question merely of honor, or of expediency. But with respect to future debts, would it not be wise and just for that nation to declare, in the constitution they are forming, that neither the legislature, nor the nation itself, can validly contract more debt than they may pay within their own age, or within the term of 19. years? And that all future contracts will be deemed void as to what shall remain unpaid at the end of 19. years from their date? This would put the lenders, and the borrowers also, on their guard. By reducing too the faculty of borrowing within it's natural limits, it would bridle the spirit of war, to which too free a course has been procured by the inattention of money-lenders to this law of nature, that succeeding generations are not responsible for the preceding.

On similar ground it may be proved that no society can make a perpetual constitution, or even a perpetual law. The earth belongs always to the living generation. They may manage it then, and what proceeds from it, as they please, during their usufruct. They are masters too of their own persons, and consequently may govern them as they please. But persons and property make the sum of the objects of government. The constitution and the laws of their predecessors extinguished then in their natural course with those who gave them being. This could preserve that being till it ceased to be itself, and no longer. Every constitution then, and every law, naturally expires at the end of 19 years. If it be enforced longer, it is an act of force, and not of right.--It may be said that the succeeding generation exercising in fact the power of repeal, this leaves them as free as if the constitution or law has been expressly limited to 19 years only. In the first place, this objection admits the right, in proposing an equivalent. But the power of repeal is not an equivalent. It might be indeed if every form of government were so perfectly contrived that the will of the majority could always be obtained fairly and without impediment. But this is true of no form. The people cannot assemble themselves. Their representation is unequal and vicious. Various checks are opposed to every legislative proposition. Factions get possession of the public councils. Bribery corrupts them. Personal interests lead them astray from the general interests of their constituents: and other impediments arise so as to prove to every practical man that a law of limited duration is much more manageable than one which needs a repeal.

This principle that the earth belongs to the living, and not to the dead, is of very extensive application and consequences, in every country, and most especially in France. It enters into the resolution of the questions Whether the nation may change the descent of lands holden in tail? Whether they may change the appropriation of lands given antiently to the church, to hospitals, colleges, orders of chivalry, and otherwise in perpetuity? Whether they may abolish the charges and privileges attached on lands, including the whole catalogue ecclesiastical and feudal? It goes to hereditary offices, authorities and jurisdictions; to hereditary orders, distinctions and appellations; to perpetual monopolies in commerce, the arts and sciences; with a long train of et ceteras: and it renders the question of reimbursement a question of generosity and not of right. In all these cases, the legislature of the day could authorize such appropriations and establishments for their own time, but no longer; and the present holders, even where they, or their ancestors, have purchased, are in the case of bonâ fide purchasers of what the seller had no right to convey.

Turn this subject in your mind, my dear Sir, and particularly as to the power of contracting debts; and develope it with that perspicuity and cogent logic so peculiarly yours. Your station in the councils of our country gives [Volume 1, Page 70] you an opportunity of producing it to public consideration, of forcing it into discussion. At first blush it may be rallied, as a theoretical speculation: but examination will prove it to be solid and salutary. It would furnish matter for a fine preamble to our first law for appropriating the public revenue; and it will exclude at the threshold of our new government the contagious and ruinous errors of this quarter of the globe, which have armed despots with means, not sanctioned by nature, for binding in chains their fellow men. We have already given in example one effectual check to the Dog of war by transferring the power of letting him loose from the Executive to the Legislative body, from those who are to spend to those who are to pay. I should be pleased to see this second obstacle held out by us also in the first instance. No nation can make a declaration against the validity of long-contracted debts so disinterestedly as we, since we do not owe a shilling which may not be paid with ease, principal and interest, within the time of our own lives.--Establish the principle also in the new law to be passed for protecting copyrights and new inventions, by securing the exclusive right for 19. instead of 14. years. Besides familiarising us to this term, it will be an instance the more of our taking reason for our guide, instead of English precedent, the habit of which fetters us with all the political heresies of a nation equally remarkeable for it's early excitement from some errors, and long slumbering under others.

The Founders' Constitution Volume 1, Chapter 2, Document 23 http://press-pubs.uchicago.edu/founders/documents/v1ch2s23.html The University of Chicago Press

The Papers of Thomas Jefferson. Edited by Julian P. Boyd et al. Princeton: Princeton University Press, 1950--.

© 1987 by The University of Chicago All rights reserved. Published 2000 http://press-pubs.uchicago.edu/founders/

To Fix America's Education Bureaucracy, We Need to Destroy It | Philip K. Howard| theatlantic.com

Successful schools don't have a formula, other than that teachers and principals are free to follow their instincts.

America's schools are being crushed under decades of legislative and union mandates. They can never succeed until we cast off the bureaucracy and unleash individual inspiration and willpower.

Schools are human institutions. Their effectiveness depends upon engaging the interest and focus of each student. A good teacher, studies show, can dramatically improve the learning of students. What do great teachers have in common? Nothing, according to studies -- nothing, that is, except a commitment to teaching and a knack for keeping the students engaged (see especially The Moral Life of Schools). Good teachers don't emerge spontaneously, and training and mentoring are indispensable. But ultimately, effective teaching seems to hinge on, more than any other factor, the personality of the teacher. Skilled teachers have a power to engage their students -- with spontaneity, authority, and wit.

Good teachers typically are found in schools with good cultures. Experts say you can tell if a school is effective within five minutes of walking in. Students are orderly and respectful when changing classes; there's a steady hum of activity. Good school culture typically grows out of good leadership. Here as well, there are many variations of success. KIPP schools have a formula that includes, for students, longer hours and strict accountability to core values, and, for teachers, a cooperative role in developing school activities and pedagogy. David Brooks recently described a highly successful school in Brooklyn that abandons the teacher-in-front-of-class model in favor of collaborative learning. Students sit around larger tables trying to solve problems or discuss the task at hand. In every successful school, whatever its theory of education, a good culture sweeps everyone along, as if by a strong tide, towards common goals of discovery and learning.

Successful teaching and good school cultures don't have a formula, but they have a necessary condition: teachers and principals must feel free to act on their best instincts. Minute by minute, as they respond to students and each other, their focus must be on doing what's right. Humans can only focus on one thing at a time, sociologist Robert Merton observed. That's why it's vital for teachers to be thinking only about how to communicate the lesson to the students in front of them. Any diversion of this focus is apt to be seen as indifference or boredom, and will break the magic.

This is why we must bulldoze school bureaucracy. It is a giant diversion, focused on compliance to please some administrator far away. Every minute spent filling out a form or worrying about compliance interferes with the human interaction that is the essence of effective teaching.

Law is everywhere in schools. It permeates every nook and cranny. Teachers spend hours every week filling out forms that no one ever reads -- because the laws and regulations that have piled up over the years require them. Hardly any interaction is free of legal implications. Teachers are instructed never -- never ever -- to put an arm around a crying child: the school might get sued. Misbehavior and disrespect are met with weakness and resignation; teachers are trained to be stoics, tolerating disorder rather than running the risk of a due process hearing in which the teacher, not the student, must justify her decision. Principals suffer a similar inversion of authority with teachers, who are armed with hundreds of pages of work rules that prescribe exactly what teachers can be asked to do. Managing a school -- say, setting the hours, deciding how to spend the budget, and deciding which teachers are doing the job --is an oxymoron. Public schools today are, by law, basically unmanageable.

Throw onto the legal pile a mono-minded compulsion -- complete with legal penalties -- to satisfy minimum standardized test scores. Recess has been canceled, arts and humanities courses scrapped, and creative interaction replaced by rote drills -- largely because of one law, known as No Child Left Behind. Another unintended effect of focusing only on the lowest performers is that all the all the other students get left behind. Teachers are treated like machine tools, their personalities and passions extruded through rigid drilling protocols. Demoralization has never been considered a good management strategy, but that's what NCLB has accomplished. One teacher in Florida put it this way: I love teaching, I love kids, but it's become harder and harder when you're teaching to the test. Can you hear the discouragement in my voice?

America's schools face many external challenges, particularly the breakdown of the nuclear family and an imbedded underclass. But numerous public, charter, and parochial schools succeed notwithstanding these challenges. What all these successful schools have in common is that somehow, usually with strong leadership, they figure out how to repress the bureaucracy and unleash the human spirit. We have a great deal of freedom here, observed a teacher at a successful school studied by Sara Lawrence-Lightfoot, because the principal protects his faculty from 'the arbitrary regulations of the central authority.'

The organizational flaw in America's schools is that they are too organized. Bureaucracy can't teach. American schools have been organized on the totally erroneous assumption, management expert Peter Drucker observed, that there is one right way to learn and it is the same for everyone. We must give educators freedom to be themselves. This doesn't mean they should be unaccountable. But they should be accountable for overall success, including, especially, success at socialization of students through a healthy school culture, not just objective test scores. This requires scrapping the current system -- all of it, federal, state, and local, as well as union contracts. We must start over and rebuild an open framework in which real people can find inspiration in doing things their own way.

This article available online at:

http://m.theatlantic.com/national/archive/2012/04/to-fix-americas-education-b...

Copyright © 2012 by The Atlantic Monthly Group. All Rights Reserved.

Sunday, July 08, 2012

Climate mythology: The Gulf Stream, European climate and Abrupt Change

Climate mythology: The Gulf Stream, European climate and Abrupt Change Richard Seager Lamont-Doherty Earth Observatory of Columbia University

A few times a year the British media of all stripes goes into a tizzy of panic when one climate scientist or another states that there is a possibility that the North Atlantic ocean circulation, of which the Gulf Stream is a major part, will slow down in coming years or even stop. Whether the scientists statements are measured or inflammatory the media invariably warns that this will plunge Britain and Europe into a new ice age, pictures of the icy shores of Labrador are shown, created film of English Channel ferries making their way through sea ice are broadcast... And so the circus continues year after year. Here is one example.

The Gulf Stream-European climate myth The panic is based on a long held belief of the British, other Europeans, Americans and, indeed, much of the world's population that the northward heat transport by the Gulf Stream is the reason why western Europe enjoys a mild climate, much milder than, say, that of eastern North America. This idea was actually originated by an American military man, Matthew Fontaine Maury, in the mid nineteenth century and has stuck since despite the absence of proof.

We now know this is a myth, the climatological equivalent of an urban legend. In a detailed study published in the Quarterly Journal of the Royal Meteorological Society in 2002, we demonstrated the limited role that ocean heat transport plays in determining regional climates around the Atlantic Ocean. Popular versions of this story can be found here, here and, in French, here.

The determinants of North Atlantic regional climates We showed that there are three processes that need to be evaluated:

1. The ocean absorbs heat in summer and releases it in winter. Regions that are downwind of oceans in winter will have mild climates. This process does not require ocean currents or ocean heat transport. 2. The atmosphere moves heat poleward and warm climates where the heat converges. In additions, the waviness in the atmospheric flow creates warm climates where the air flows poleward and cold climates where it flows equatorward. 3. The ocean moves heat poleward and will warm climates where it releases heat and the atmosphere picks it up and moves it onto land.

Using observations and climate models we found that, at the latitudes of Europe, the atmospheric heat transport exceeds that of the ocean by several fold. In winter it may even by an order of magnitude greater. Thus it is the atmosphere, not the ocean, that does the lion's share of the work ameliorating winter climates in the extratropics. We also found that the seasonal absorption and release of heat by the ocean has a much larger impact on regional climates than does the movement of heat by ocean currents.

Seasonal storage and release accounts for half the winter temperature difference across the North Atlantic Ocean. But the 500 pound gorilla in how regional climates are determined around the Atlantic turned out to be the Rocky Mountains. Because of the need to conserve angular momentum, as air flows from the west across the mountains it is forced to first turn south and then to turn north further downstream. As such the mountains force cold air south into eastern North America and warm air north into western Europe. This waviness in the flow is responsible for the other half of the temperature difference across the North Atlantic Ocean.

Hence:

1. Fifty percent of the winter temperature difference across the North Atlantic is caused by the eastward atmospheric transport of heat released by the ocean that was absorbed and stored in the summer. 2. Fifty percent is caused by the stationary waves of the atmospheric flow. 3. The ocean heat transport contributes a small warming across the basin.

The seasonal ocean heat storage and pattern of atmospheric heat transport add up to make winters in western Europe 15 to 20 degrees C warmer than those in eastern North America. A very similar process occurs across the Pacific Ocean. The ocean heat transport warms the North Atlantic Ocean and the land on both sides by a modest few degrees C. The only place where the ocean heat transport fundamentally alters climate is along the coast of northern Norway which would be sea ice-covered were it not for the warm northward flowing Norwegian Current.

The Gulf Stream and future climate change A slowdown of the Gulf Stream and ocean circulation in the future, induced by freshening of the waters caused by anthropogenic climate change (via melting glaciers and increased water vapor transport into high latitudes) or simply by warming, would thus introduce a modest cooling tendency. This would leave the temperature contrast across the Atlantic unchanged and not plunge Europe back into the ice age or anything like it. In fact the cooling tendency would probably be overwhelmed by the direct radiatively-driven warming by rising greenhouse gases.

North Atlantic Ocean circulation and abrupt climate change The conflation of the Gulf Stream, ocean heat transport and Europe's climate has led to changes in ocean circulation being the reigning theory of the cause of glacial era abrupt climate change. These abrupt changes - the Dansgaard-Oeschger events of the last ice age and the Younger Dryas cold reversal of the last deglaciation - are well recorded in the Greenland ice core and Europe and involved changes in winter temperature of as much as thirty degrees C! For the Younger Dryas it has been proposed that the sudden release of glacial meltwater from ice dammed Lake Agassiz freshened the North Atlantic and shut down the overturning circulation causing dramatic regional coooling.

Only through an inflated view of the impact of ocean circulation could it be thought that the enormous glacial era abrupt changes were caused by changes in ocean circulation. Instead, as we have argued, changes in atmospheric circulation regimes had to be the driver, see (Seager and Battisti,2007). Determining how this could happen has become more of a priority now that the geological evidence for the Lake Agassiz flood has not been found, see (Broecker,2006).

Moving beyond the myth It is long time that the Gulf Stream-European climate myth was resigned to the graveyard of defunct misconceptions along with the Earth being flat and the sun going around the Earth. In its place we need serious assessments of how changes in ocean circulation will impact climate change and a new look at the problem of abrupt climate change that gives the tropical climate system and the atmosphere their due as the primary drivers of regional climates around the world.

Publications

Seager, R., D. S. Battisti, J. Yin, N. Gordon, N. H. Naik, A. C. Clement and M. A. Cane, 2002: Is the Gulf Stream responsible for Europe's mild winters? Quarterly Journal of the Royal Meteorological Society, 128(586): 2563-2586. PDF Seager, R. and D. S. Battisti, 2007: Challenges to our understanding of the general circulation: abrupt climate change. In: T. Schneider and A.S. Sobel (Editors), The Global Circulation of the Atmosphere: Phenomena, Theory, Challenges. Princeton University Press, pp. 331-371. PDF. Seager, R., 2006: The source of Europe's mild climate. American Scientist, 94(4): 334-341. PDF. Seager, R., 2008: Setting the record straight on Europe's mild winters. The Plantsman, Royal Horticultural Society,7, Part 1 March, p.22-27. PDF. Seager, R., 2003: Gulf Stream la fin d'un mythe. La Recherche(361): 40-46.PDF

The American Heat Wave and Global Warming | scietopia Blog

Global warming is a big issue. If we're honest and we look carefully at the data, it's beyond question that the atmosphere of our planet is warming. It's also beyond any honest question that the preponderance of the evidence is that human behavior is the primary cause. It's not impossible that we're wrong - but when we look at the real evidence, it's overwhelming.

Of course, this doesn't stop people from being idiots.

But what I'm going to focus on here isn't exactly the usual idiots. See, here in the US, we're in the middle of a dramatic heat wave. All over the country, we've been breaking heat daily temperature records. As I write this, it's 98 degrees outside here in NY, and we're expecting another couple of degrees. Out in the west, there are gigantic wildfires, cause by poor snowfall last winter, poor rainfall this spring, and record heat to dry everything out. So: is this global warming?

We're seeing lots and lots of people saying yes. Or worse, saying that it is, because of the heat wave, while pretending that they're not really saying that it is. For one, among all-too-many examples, you can look at Bad Astronomy here. Not to rag too much on Phil though, because hes just one among about two dozen different example of this that I've seen in the last 3 days.

Weather 10 or twenty degree above normal isn't global warming. A heat wave, even a massive epic heat wave, isn't proof that global warming is real, any more than an epic cold wave or blizzard is evidence that global warming is fake.

I'm sure you've heard many people say weather is not climate. But for human beings, it's really hard to understand just what that really means. Climate is a world-wide long-term average; weather is instantaneous and local. This isn't just a nitpick: it's a huge distinction. When we talk about global warming, what we're talking about is the year-round average temperature changing by one or two degrees. A ten degree variation in local weather doesn't tell us anything about the worldwide trend.

Global warming is about climate. And part of what that means is that in some places, global warming will probably make the weather colder. Cold weather isn't evidence against global warming. Most people realize that - which is why we all laugh when gasbags like Rush Limbaugh talk about how a snowstorm proves that global warming is a fraud. But at the same time, we look at weather like what we have in the US, and conclude that Yes, global warming is real . But we're making the same mistake.

Global warming is about a surprisingly small change. Over the last hundred years, global warming is a change of about 1 degree Celsius in the global average temperature. That's about 1 1/2 degrees Fahrenheit, for us Americans. It seems miniscule, and it's a tiny fraction of the temperature difference that we're seeing this summer in the US.

But that tiny difference in climate can cause huge differences in weather. As I mentioned before, it can make local weather either warmer or colder - not just by directly warming the air, but by altering wind and water currents in ways that create dramatic changes.

For example, global warming could, likely, make Europe significantly colder. How? The weather in western Europe is greatly affected by an ocean water current called the atlantic conveyor. The conveyor is a cyclic ocean current, where (driven in part by the jet stream), warm water flows north from the equator in a surface current, cooling as it goes, until it finally sinks and starts to cycle back south in a deep underwater current. This acts as a heat pump, moving energy from the equator north and east to western Europe. This is why Western Europe is significantly warmer than places at the same latitude in Eastern North America.

Global warming could alter the flow of the Atlantic conveyor. (We don't know if it will - but it's one possibility, which makes a good example of something counter-intuitive.) If the conveyor is slowed, so that it transfers less energy, Europe will get colder. How could the conveyor be slowed? By ice-melt. The conveyor works as a cycle because of the differences in density between warm and cold water: cold water is denser than warm water, so the cold water sinks as it cools. It warms in the tropics, gets pushed north by the jet stream, cools along the way and gradually sinks.

But global warming is melting a lot of Arctic and glacier ice, which produces freshwater. Freshwater is less dense than saltwater. So the freshwater, when it dilutes the cold water at the northern end of the conveyor, it reduces its density relative to the pure salt-water - and that reduces the tendency of the cold water to sink, which could slow the conveyor.

There are numerous similar phenomena that involve changes in ocean currents and wind due to relatively small temperature variations. El Nino and La Nina, conveyor changes, changes in the moisture-carrying capacity of wind currents to carry - they're all caused by relatively small changes - changes well with the couple of degrees of variation that we see occurring.

But we need to be honest and careful. This summer may be incredibly hot, and we had an unusually warm winter before it - but we really shouldn't try to use that as evidence of global warming. Because if you do, when some colder-than-normal weather occurs somewhere, the cranks and liars that want to convince people that global warming is an elaborate fraud will use that the muddle things - and when they do, it'll be our fault when people fall for it, because we'll be the ones who primed them for that argument. As nice, as convenient, as convincing as it might seem to draw a correlation between a specific instance of extreme weather and global warming, we really need to stop doing it.

Sunday, July 01, 2012

What Really Makes Us Fat By GARY TAUBES | New York Times

June 30, 2012

A CALORIE is a calorie. This truism has been the foundation of nutritional wisdom and our beliefs about obesity since the 1960s.

What it means is that a calorie of protein will generate the same energy when metabolized in a living organism as a calorie of fat or carbohydrate. When talking about obesity or why we get fat, evoking the phrase “a calorie is a calorie” is almost invariably used to imply that what we eat is relatively unimportant. We get fat because we take in more calories than we expend; we get lean if we do the opposite. Anyone who tells you otherwise, by this logic, is trying to sell you something.

But not everyone buys this calorie argument, and the dispute erupted in full force again last week. The Journal of the American Medical Association published the results of a clinical trial by Dr. David Ludwig of Boston Children’s Hospital and his collaborators. While the media tended to treat the study as another diet trial — what should we eat to maintain weight loss? — it spoke to a far more fundamental issue: What actually causes obesity? Why do we get fat in the first place? Too many calories? Or something else?

The calorie-is-a-calorie notion dates to 1878, when the great German nutritionist Max Rubner established what he called the isodynamic law.

It was applied to obesity in the early 1900s by another German — Carl Von Noorden, who was of two minds on the subject. One of his theories suggested that common obesity was all about calories in minus calories out; another, that it was about how the body partitions those calories, either for energy or into storage.

This has been the core of the controversy ever since, and it’s never gone away. If obesity is a fuel-partitioning problem — a fat-storage defect — then the trigger becomes not the quantity of food available but the quality. Now carbohydrates in the diet become the prime suspects, especially refined and easily digestible carbohydrates (foods that have what’s called a high glycemic index) and sugars.

UNTIL the 1960s, carbohydrates were indeed considered a likely suspect in obesity: “Every woman knows that carbohydrate is fattening,” as two British dietitians began a 1963 British Journal of Nutrition article.

The obvious mechanism: carbohydrates stimulate secretion of the hormone insulin, which works, among other things, to store fat in our fat cells. At the time, though, the conventional wisdom was beginning its shift: obesity was becoming an energy issue.

Carbohydrates, with less than half the calories per gram as fat, were beginning their official transformation into heart-healthy diet foods. One reason we’ve been told since to eat low-fat, carbohydrate-rich diets is this expectation that they’ll keep us thin.

What was done by Dr. Ludwig’s team has never been done before. First they took obese subjects and effectively semi-starved them until they’d lost 10 to 15 percent of their weight. Such weight-reduced subjects are particularly susceptible to gaining the weight back. Their energy expenditure drops precipitously and they burn fewer calories than people who naturally weigh the same. This means they have to continually fight their hunger just to maintain their weight loss. The belief is that weight loss causes “metabolic adaptations,” which make it almost inevitable that the weight will return. Dr. Ludwig’s team then measured how many calories these weight-reduced subjects expended daily, and that’s how many they fed them. But now the subjects were rotated through three very different diets, one month for each. They ate the same amount of calories on all three, equal to what they were expending after their weight loss, but the nutrient composition of the diets was very different.

One diet was low-fat and thus high in carbohydrates. This was the diet we’re all advised to eat: whole grains, fruits, vegetables, lean sources of protein. One diet had a low glycemic index: fewer carbohydrates in total, and those that were included were slow to be digested — from beans, non-starchy vegetables and other minimally processed sources. The third diet was Atkins, which is very low in carbohydrates and high in fat and protein.

The results were remarkable. Put most simply, the fewer carbohydrates consumed, the more energy these weight-reduced people expended. On the very low-carbohydrate Atkins diet, there was virtually no metabolic adaptation to the weight loss. These subjects expended, on average, only 100 fewer calories a day than they did at their full weights. Eight of the 21 subjects expended more than they did at their full weights — the opposite of the predicted metabolic compensation.

On the very low-carbohydrate diet, Dr. Ludwig’s subjects expended 300 more calories a day than they did on the low-fat diet and 150 calories more than on the low-glycemic-index diet. As Dr. Ludwig explained, when the subjects were eating low-fat diets, they’d have to add an hour of moderate-intensity physical activity each day to expend as much energy as they would effortlessly on the very-low-carb diet. And this while consuming the same amount of calories. If the physical activity made them hungrier — a likely assumption — maintaining weight on the low-fat, high-carb diet would be even harder. Why does this speak to the very cause of obesity? One way to think about this is to consider weight-reduced subjects as “pre-obese.” They’re almost assuredly going to get fatter, and so they can be research stand-ins — perhaps the best we have — for those of us who are merely predisposed to get fat but haven’t done so yet and might take a few years or decades longer to do it.

If we think of Dr. Ludwig’s subjects as pre-obese, then the study tells us that the nutrient composition of the diet can trigger the predisposition to get fat, independent of the calories consumed. The fewer carbohydrates we eat, the more easily we remain lean. The more carbohydrates, the more difficult. In other words, carbohydrates are fattening, and obesity is a fat-storage defect. What matters, then, is the quantity and quality of carbohydrates we consume and their effect on insulin.

From this perspective, the trial suggests that among the bad decisions we can make to maintain our weight is exactly what the government and medical organizations like the American Heart Association have been telling us to do: eat low-fat, carbohydrate-rich diets, even if those diets include whole grains and fruits and vegetables.

A controversial conclusion? Absolutely, and Dr. Ludwig’s results are by no means ironclad. The diets should be fed for far longer than one month, something he hopes to do in a follow-up study. As in any science, these experiments should be replicated by independent investigators. We’ve been arguing about this for over a century. Let’s put it to rest with more good science. The public health implications are enormous.

Gary Taubes is The author of “Why We Get Fat.”


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