The New York Times recently published an interesting op-ed on the subject of salt. Its thesis is, first, that we have been and are being told by a variety of authoritative sources that we ought to consume less salt, second, that there is not and never has been adequate scientific support for that claim, and third that there is now evidence suggesting that the official advice is not merely mistaken but dangerous, that reducing salt consumption to the recommended level might well be bad for one's health.
What struck me about the piece was not mainly its contents—I had seen reports in the past on evidence that reducing salt consumption was bad for one's health—but its placement. I am not a regular reader of the Times, but my impression is that, in other contexts, it is sympathetic to arguments from official truth, arguments that start with some version of "all scientists agree that" and treat anyone who disagrees as either misinformed or in the pay of some interest group that wants the truth suppressed. Global warming is the obvious example, but I think there are others. So it was interesting to see them publish a piece debunking one version of that argument.
A close parallel to the case of salt is the case of saturated fat. A few decades back, the official wisdom, promoted by more or less the same sorts of authorities that now tell us to eat less salt, was that saturated fat was bad for the heart and one should therefor switch from butter to margarine. Further research eventually led to the conclusion that, while saturated fat was somewhat bad for the heart, trans-fats were much worse—and the margarine we were being told to switch to was made from hydrogenated vegetable oil, hence replaced saturated fats with trans-fats. In that case, as best I can tell, the official advice was not merely wrong but lethally wrong, a fact which led to less skepticism about official truth than it should have. Any readers better informed about the subject—nutrition is not an area where I can claim any expertise—are welcome to correct my account, but I think it is accurate.
I was, perhaps, less inclined than most to take official truth at face value due to early experiences in what was to become my field. As an undergraduate at Harvard in the early sixties, I had a conversation with a fellow undergraduate who informed me—he had no idea who I was—that he could not take an economics course at Chicago because he would burst out laughing. Even aside from what I knew about the controversy between the Chicago and Harvard schools, it seemed to me that the fact that a student who had probably taken one introductory course in the field thought himself competent to judge, with confidence, which school was correct, was a good reason to be skeptical of the claims of his teachers. And, within a decade or two, the Harvard school had largely conceded that, on at least some of the debated points, they had been wrong.
In the case of global warming, I am inclined to accept the official version of the climate science, since I don't know enough about the subject to be competent to question it. But the official version of the associated economics, the claim that the rate of warming implied by the climate science will have large negative effects, strikes me as unconvincing and probably wrong, for reasons I have discussed here in the past.
(Many more of my posts on the subject.)
28 comments:
Regarding nutrition: Pick an evil nutrient X (saturated fat, high glycemic index potatoes, meat, etc.) and you can probably find a native population that consumes it in horrifying quantities while remaining very healthy, with low rates of obesity, heart disease and diabetes. This really puts a dent in one's faith in observational studies.
Of course, one can respond that these populations are "adapted" to such foods, but we're all human beings ... how metabolically different are we?
"Of course, one can respond that these populations are "adapted" to such foods, but we're all human beings ... how metabolically different are we?"
Well ... there is that thing with Native Americans and alcohol that has been going on for a few hundred years, so I'm guessing that adaptation takes some time.
In the case of global warming, I am inclined to accept the official version of the climate science, since I don't know enough about the subject to be competent to question it. But the official version of the associated economics, the claim that the rate of warming implied by the climate science will have large negative effects, strikes me as unconvincing and probably wrong, for reasons I have discussed here in the past.
What 'official' version would that be? Are we supposed to accept the word of the political appointees at the IPCC, who refuse to look at data that does not agree with the 'expected' conclusion?
The point here David is that there is NO EMPIRICAL EVIDENCE that HUMAN EMISSIONS OF CO2 are a material factor in the change of temperature trends. When you can provide such empirical evidence you can claim to have support for your belief. But until then you are just as foolish as that student who thought that the flawed Keynesian ideas taught at Harvard were any better then the flawed Monetarist ideas taught at Chicago.
The point here David is that there is NO EMPIRICAL EVIDENCE that HUMAN EMISSIONS OF CO2 are a material factor in the change of temperature trends.
There are six things that must be demonstrated before governments should take large scale action on global warming:
1. Anthropogenic global warming is real.
2. It is significant and outside the bounds of normal climate variation.
3. It has a significant impact on humanity.
4. The negative impacts on humanity are greater than the positive impacts.
5. The costs of directly addressing global warming are less than the costs it imposes on humanity or the costs required to otherwise mitigate the consequences.
6. Governments have the means and competence to directly address global warming without creating greater collateral costs.
Why would you (or David) make your stand on #1 -- the expertise of the proponents of governments' doing something about global warming -- when you could make your stand on the other necessary stages of the argument that climate change proselytizers utterly ignore?
Those who argue for action on climate change want you to fight on their turf! It distracts everyone from the real weaknesses of their position.
Your details about saturated fat are correct, but I think your overall conclusion is wrong. The isolated advice to switch from butter to then existing margarine was wrong, but the general advice to reduce saturated fat was correct and its net effect is generally credited with the 50% reduction in cardiovascular disease of the past half century.
Those who argue for action on climate change want you to fight on their turf! It distracts everyone from the real weaknesses of their position.
I am not fighting on anyone's turf. I am simply pointed out to David that there is no empirical evidence of AGW and am somewhat pissed off at the claim that there is an 'official' position that is anything but political.
We are actually in a cooling trend right now. Much of the paleoclimatology claims have long been discredited and the empirical evidence is showing a much larger influence by solar activity than by greenhouse gasses. This is exactly why so many of the warmers have abandoned the sinking ship and are now regrouping under the biodiversity banner.
Your details about saturated fat are correct, but I think your overall conclusion is wrong. The isolated advice to switch from butter to then existing margarine was wrong, but the general advice to reduce saturated fat was correct and its net effect is generally credited with the 50% reduction in cardiovascular disease of the past half century.
"Generally credited"? Sorry but that is a meaningless statement. You can credit a reduction in cardiovascular disease by a decrease in smoking and alcohol consumption, and by an increase in exercise. Or many other factors. To figure out what the driver is you need a lot more work to be done.
By "generally credited," I mean that it is the consensus among epidemiologists.
By "generally credited," I mean that it is the consensus among epidemiologists.
But wasn't there a 'consensus' about the need to eat lots of carbs? Or that salt was 'bad' for your health?
When it comes to complex systems like the human body I am in the Nassim Taleb camp that argues the 'experts' are little more than empty suits. They think that they know more than they actually know and are usually wrong but never in doubt.
I've been getting along happily enough without butter or margarine for many years.
Like many other people, I was brought up to spread a layer of butter over bread before eating it. But I discovered in my early 20s that it's not actually necessary to spread any fatty substance over bread, it tastes fine without it. Unless it's just bad bread, of course...
To get back on subject: I had the very same feeling upon reading that salt article. 'Is this the new york times?'.
The feeling was particularly pronounced since a few days earlier I ran into yet another Gary Taubes article in that very same New York Times, assailing yet another sacred cow of official truth, namely the evils of fat and the (relative) nothing-to-see-here attitude towards carbs.
I guess newspapers that have their stock value ruthlesly decimated make strange jumps. Before you know it theyll have Steve McIntyre write an article on scientific standards (or the lack thereof) in paleoclimatology...
Well we also have to argue what butter is. What is being sold in the US under the generic name "butter" is very different from what real butter is. Same goes for milk and other lactate products. Then look at the cows themselves and their diet (they are fed animal parts among other things) so even if it turns out butter is not as dangerous to one's health as previously thought, the "butter" sold in most US stores is pure poison - for reasons other than the saturated fat content. The main solution is to look for healthy fats elsewhere (avocados?) or to buy land, get a cow, make sure it eats grass, milk it, and make butter/cheese/cream at home. Not very practical unfortunately, but alas, all decisions in life involve trade-offs.
To further the discussion on saturated fats, nutritionist/exercise guru Mike Geary (Truth About Abs) has very interesting views. I have not paid him a single cent, but I have been receiving his newsletter for over a year now, and even though I am no biologist/scientist, his common sense advice regarding food makes sense to me as well (I had family members who were subsistence farmers, and consumed a lot of saturated fats, their diet was very different from contemporary American diet, and their health was comparable if not better than that of most American eating "healthy" foods, such as low-fat everything). Unfortunately, I am too lazy to follow his exercise advice, although the general ideas stuck with me (100 m runners look healthy, marathon runners look sickly, since the human body is made for quick efforts rather than sustained exertion; jogging is bad for knees and health, although still better than inactivity etc). For nutrition, his rule of thumb is to buy only 1-ingredient items at the store (to avoid unhealthy processing of food) and that fats, including saturated fats, are not bad, but that certain processes of most modern foods render this unhealthy. I am in no way associated with his marketing efforts and like I said, I have been a freeloader receiving his free newsletter only.
i think that a lot of the problem about global warming comes from articles that start with th words we have discovered a trend... what actually happens is they make a computer model and based on that model thy make predictions. the problems with science done in this way are many but to me it seems the problem is inherent in commuter modeling itself. there are differential equations that if you draw a graph and do Taylor expansion and connect the dots you get a smooth graph. This is how insolvable equations are graphed. But the problem is that the Taylor expansion can miss places in which the equation acts completely different.
Mike,
I agree with your 6 points, but I think it necessary to add a couple of others:
7. Are there less costly alternative solutions like engineered volcanoes to darken the skies?
8. Why should the government be in the business of choosing winners and losers in the global warming controversy? Raising taxes or hobbling our energy choices (maybe) go to the ultimate benefit of the breeders' progeny but they certainly cost folks like me who are too old to buy green bananas or enjoy any beneficial results of the tremendous sacrifices.
jimbino,
Good points.
On #7, I prefer to view geoengineering as insurance against the 0.5% chance that the atmosphere will turn into a runaway anoxic hellscape. Given that studies such as those of Nordhaus find so little gain in governments' actively addressing global warming, we're better off doing nothing about it but holding the insurance policy against truly bad outcomes.
And #8 is a good point. How do you balance a longer growing season and much healthier climate in Canada and Russia against a higher sea level in the Seychelles?
That position also implies Coasian questions and takes issues of right and wrong out of the picture. In fact, if you remove "anthropogenic" from my #1, the rest of #2-#6 hold. Even if humanity has no part at all in causing climate change, if climate change is real and disastrous to humanity, we still would want to do something about it.
7. Are there less costly alternative solutions like engineered volcanoes to darken the skies?
Clearly these volcanoes would harm some people. Why would that be desirable or moral?
The scientific reason to discount CO2 as a potential threat (as if a warmer climate were truly a threat), is because of Beer's Law, which says that there is a logarithmic dependence between the transmissivity of light through a substance and the product of the absorption coefficient of the substance (with some deviations in absorption coefficient at high concentrations due to electrostatic interactions between molecules in close proximity).
The IPCC acknowledged this limit in their 3rd Assessment Report: "Carbon dioxide absorbs infrared radiation in the middle of its 15 mm band to the extent that radiation in the middle of this band cannot escape unimpeded: this absorption is saturated. This, however, is not the case for the band's wings. It is because of these effects of partial saturation that the radiative forcing is not proportional to the increase in the carbon dioxide concentration but shows a logarithmic dependence. Every further doubling adds an additional 4 Wm-2 to the radiative forcing."
So far, human activity hasn't even doubled the pre-industrial CO2 levels even once, but it would require another doubling of CO2 from the current level just to raise the temperature by about 1.2°C. It would require a quadrupling of CO2 to raise temperatures by up to 2.4°C. There aren't enough fossil fuels within the planet to do that!
The games that the IPCC has been playing and calling science, in order to get around this fact of physics, even came out in their own 4th Assessment Report:
"The strong effect of cloud processes on climate model sensitivities to greenhouse gases was emphasized further through a now-classic set of General Circulation Model (GCM) experiments, carried out by Senior and Mitchell (1993). They produced global average surface temperature changes (due to doubled atmospheric CO2 concentration) ranging from 1.9° C to 5.4°C, simply by altering the way that cloud radiative properties were treated in the model. It is somewhat unsettling that the results of a complex climate model can be so drastically altered by substituting one reasonable cloud parameterization for another, thereby approximately replicating the overall intermodel range of sensitivities."
The entire political argument extends not from an actual empirical relationship between carbon dioxide concentrations and temperature then, but from wild guestimates about how water vapor, clouds, and other processes feed back on a very minor temperature increase. If those guestimates were even remotely true, simple seasonal fluctuations would cause catastrophic warmings and coolings, which we obviously don't see in reality. The truth is that our oceans, clouds, biosphere, and other systems all act, in aggregate, as buffers to prevent wild swings in climate, not to amplify them. The IPCC ignores all negative feedbacks and overestimates positive feedbacks in order to create models that have nothing to do with reality but which promote their political agenda.
Dr. Roy Spencer, Ph.D, former NASA climatologist, observed, "I found from the CERES data a strongly negative SW [short wave] feedback during 2002-2007. When added to the LW [long wave] feedback, this resulted in a total (SW+LW) feedback that is strongly negative." He further complained, "Is my work published? No... at least not yet... although I have tried. Apparently it disagrees too much with the IPCC party line to be readily acceptable. My finding of negative SW feedback of around 5 W m-2 K-1 from real radiation budget data (the CERES instrument on Aqua) is apparently inadmissible as evidence. In contrast, Dessler et al.’s finding of positive LW feedback of 2 W m-2 K-1 inferred from the AIRS instrument is admissible."
In other words, high-albedo cloud formation negatively feeds back on temperature increases, preventing any kind of runaway greenhouse effect. But this information is not allowed to be officially published.
It is through this censoring and blacklisting of opposing views that the politicians and political activists have constructed the scientifically-incompatible concept of a "scientific consensus". There's no such thing as consensus in science. Science is predicated on skepticism. U.S Government Atmospheric Scientist Stanley B. Goldenberg of the Hurricane Research Division of NOAA admitted that, "It is a blatant lie put forth in the media that makes it seem there is only a fringe of scientists who don’t buy into anthropogenic global warming."
What is being sold in the US under the generic name "butter" is very different from what real butter is. Same goes for milk and other lactate products.
What on earth are you talking about?
Then look at the cows themselves and their diet (they are fed animal parts among other things)
What's wrong with that?
so even if it turns out butter is not as dangerous to one's health as previously thought, the "butter" sold in most US stores is pure poison - for reasons other than the saturated fat content.
"Pure poison"?! This is arrant nonsense, and discredits anything else you might have to say.
If the markets demanded global warming, it would already have happened. Same applies to space aliens.
"the practical purpose of politics is to keep the [populace scared and eager to be led to safety by frightening them with an endless series of hobgoblins, all of them imaginary." Mencken
Yhe politicians used to have Stalin to frighten people with but now they are down to the less crdible catastrophic global warming and salt.
I really do think there is a degree of desperation about such scares reminiscent of collapsing empires.
the general advice to reduce saturated fat was correct and its net effect is generally credited with the 50% reduction in cardiovascular disease of the past half century.
Your contention that there has been a 50% reduction in cardiovascular disease over the past 50 years is laughable, and utterly incorrect. Good luck citing a reliable source backing up that statistic. Cardiovascular disease, diabetes and obesity rates have all been on the rise during that time, and the "Fat is Bad" lie is a big player in the cause.
For those interested in a quick and informative history of heart disease, here is a link that shows a timeline about the ways government went wrong in its recommendations, when credible scientists were ignored, and statistics about the devastating results on our nation's health.
http://www.dietheartpublishing.com/diet-heart-timeline
After much research, our family went high fat/low carb, and in less than a year went from borderline obese to thin. We were diabetes and heart disease patients in the making, and now we aren't. Our anecdotal experience isn't statistically relevant - but it was surely relevant for us. We started eating fat, stopped eating sugar, "whole grain" or any other kind of bread and pasta, and our extra weight just melted away. That's not what the government says will happen.
In my experience, the easiest way to overcome the "Fat is Bad" brainwashing is to read the book Why We Get Fat, by Gary Taubes. Once we figure out why we get fat (and it's not because we are lazy or gluttonous), we then understand why we get heart disease and diabetes. They are linked, because they all have the same underlying cause, and it isn't saturated fat.
"But the official version of the associated economics, the claim that the rate of warming implied by the climate science will have large negative effects, strikes me as unconvincing and probably wrong, for reasons I have discussed here in the past."
"I would go even further, and say that even if the official version of the economics is correct, there would still be a questionable moral case for this generation reducing emission for the benefit of future generations. Here's the analogy I gave after a post by Robert Murphy on the MasterResource blog:
Here’s an analogy about why I think the present generation is not morally responsible for eliminating global warming, so that future generations don’t have to deal with it.
Suppose I have a house that I got from my parents. And suppose I added a lot of new rooms and appliances, new carpeting, and other good things.
Suppose I give it to my chidren when I die. And suppose that right before I die, I crash the lawnmower into the air conditioning compressor outside the house, and totally destroy the compressor.
Do I have a moral obligation to spend my money to fix the compressor before I give the house to my children when I die? No, I don’t think I do…and I think most people would agree with me.
Global warming is analogous to that broken air conditioning compressor. We’re going to give our children and grandchildren a house (earth) and it will be better than the one we got from our parents (new rooms, new appliances, new carpeting)…except for that broken air conditioning compressor.
We don’t have any moral obligation to give our children and grandchildren a perfect world. Simply giving them a better world than we inherited should be enough."
"Your contention that there has been a 50% reduction in cardiovascular disease over the past 50 years is laughable, and utterly incorrect. Good luck citing a reliable source backing up that statistic."
How about the Centers for Disease Control?
CDC, rates of heart disease, 1900-1999
Really interesting comments, I like MikeP's articulation of the six elements from which the climate alarmists base their attacks on liberty; six elements, all unproved by the way.
As to saturated fat, there's never been an intervention study which proved that saturated fat intake as an independent variable is damaging to the cardiovascular system. Even the epidemiologists agree that studies prove diets high in saturated fat and low in carbohydrate result in improved health markers for periods of up to a year (money not yet spent for longer intervention studies). The story is told most thoroughly in "Good Calories Bad Calories" - after reading that book (in my case, four times and writing about what I learned so I could retain the relevant detail), anyone can think their way through the mishmash of diet/health "science" and design a diet that will show rapid, short term results.
Once you have eaten a satisfying, hunger reducing, energy stabilizing high fat diet and reduced your body fat, blood pressure, triglycerides, and abdominal circumference, you won't be too concerned when the next ridiculous epidemiological study proclaiming the risks of animal foods is announced.
In short, if you want to take control of your health, do not trust the Official Truth.
Post a Comment