Wednesday, August 29, 2007

Climate Complications

Freeman Dyson has an interesting essay on heresy, global warming and much else. He argues that we don't know nearly enough to predict what will happen to climate, what the human contribution to climate change is, or whether likely changes are on net good or bad. In particular, we do not understand the biological part of the equation very well--the effect of increases in CO2 or changes in human land use on the amount of carbon tied up in topsoil.

When I point out how small the predicted effects are of global warming--a few degrees increase in temperature and a foot or so in sea level over the next century--a common response is that the average effects understate the costs. Dyson implies the opposite conclusion:

In humid air, the effect of carbon dioxide on radiation transport is unimportant because the transport of thermal radiation is already blocked by the much larger greenhouse effect of water vapor. The effect of carbon dioxide is important where the air is dry, and air is usually dry only where it is cold. Hot desert air may feel dry but often contains a lot of water vapor. The warming effect of carbon dioxide is strongest where air is cold and dry, mainly in the arctic rather than in the tropics, mainly in mountainous regions rather than in lowlands, mainly in winter rather than in summer, and mainly at night rather than in daytime. The warming is real, but it is mostly making cold places warmer rather than making hot places hotter. To represent this local warming by a global average is misleading.

One of the best bits of the essay deals not with global warming but with the tension between "naturalist" and "humanist" views of the world:

Here I must confess my own bias. Since I was born and brought up in England, I spent my formative years in a land with great beauty and a rich ecology which is almost entirely man-made. The natural ecology of England was uninterrupted and rather boring forest. Humans replaced the forest with an artificial landscape of grassland and moorland, fields and farms, with a much richer variety of plant and animal species. Quite recently, only about a thousand years ago, we introduced rabbits, a non-native species which had a profound effect on the ecology. Rabbits opened glades in the forest where flowering plants now flourish. There is no wilderness in England, and yet there is plenty of room for wild-flowers and birds and butterflies as well as a high density of humans. Perhaps that is why I am a humanist.


Anonymous said...

it's good to live under the shadow of giants in where we could share their honest and sharp point of view, rather than bombed by the threat given by pseudoscientists and lobbyists and activists.

Russ Nelson said...

Yay Freeman!

montestruc said...

Minor point about Dyson's comments on the relative importance of CO2 & H20 vapor in radiation heat transfer. He is 100% right that CO2 is dwarfed in import by H2O when the humidity is high, however he misses a major issue.

High humidity is a phenomena of the lower atmosphere, as the temperature of the air drops (a lot) with altitude, everywhere on earth such that by the time you get to say 6000 meters (close to 20,000 feet), the temperatures get really cold (-24 C) and water freezes and snows out, and you are still well below half the mass of the atmosphere and at about 1/2 the density at sea level. CO2 is much better distributed than H2O as it does not snow out, and 6000 meters is at an altitude where water vapor is no longer a big player in radiation other than as clouds, and not much then as most clouds are much lower than that.

Anonymous said...

idiot's opinion:

is co2 heavier than o2? in this sense , is the co2 as abundant as on the surface?

Tim Lambert said...

Dyson omits the fact that the warming is greater over the land than over the oceans, so that warming on the land will be grater than for the globe. Most people live on land rather than in the ocean.

jimbino said...

We wouldn't have to endure the endless chatter about global warming and man's influence on it if we were to reduce pollution of the planet by limiting the breeding of ever more humans.

That simple measure would give us cleaner air and smaller classrooms, extend our energy supply, lower our taxes and make animal and plant life rejoice the world over.

It is the Chinese who are doing the planet a big favor by their policy of limiting breeding.

Anonymous said...

Who is the "we" who are supposed to limit human breeding? Effectively all the developed, industrialized economies already have low or even negative growth rates; in some cases, such as Japan, projected population for midcentury is significantly less than current population, according to estimates that I've seen. The continuing growth is taking place in countries that are still desperately poor.

Such countries, as a rule, don't have effective governments; I don't see them as likely to implement population limitation. And a lot of them have indigenous cultures that are very pronatalist, so changing the local behavior would probably take government that was substantially more totalitarian than a simple kleptocracy.

So should the industrial nations, or the United States in particular, step in and force population restriction on all those poor countries? That seems dubious on ethical grounds, and even more so on practical grounds, considering how much trouble the United States is having with Iraq alone.

Jonathan said...

In response to Jimbino, I'm enthusiastically in favour of a drop in world population to well below current levels, but forbidding births by government decree is grossly antilibertarian.

Last I heard, projections of world population suggested that it will rise to a peak in the relatively near future and then decline steadily, because wealthier people tend to breed less and most countries are gradually becoming wealthier.

Less cheerily, some of the poorer parts of the world sometimes suffer catastrophic loss of population due to war or disease.

Jonathan said...

Interesting point about the boring forests of ancient Britain giving way to a more exciting man-made ecology. I haven't heard this one before. I wonder if it's an uncontroversial point of view among ecologists.

Arthur B. said...

Jonathan & jimbibo:

By all mean we live in a world were resources are far more abundant than labor. Additional people means more leisure and more wealth for everyone.
Not only does the supply of labor increase but more innovation and intellectual works are produced.

Malthusian most often fail to grasp the ingenuosity of the human race and the efficiency of capitalism.

Anonymous said...

Being "enthusiastic" about a decline in human population strikes me as rather creepy and misanthropic. That's not to say it's unambiguously bad - there are some pluses and minuses.

Ultimately, the current population crash in some societies will reverse. Natural selection will weed out those characteristics that lead to reproductive failure in industrial societies.

Jonathan said...

More people means more pollution, more noise, more traffic, housing more expensive and harder to find, and so on and forth.

I value people as individuals, as friends. Large masses of millions of people -- complete strangers to each other -- only get in each other's way and cause nuisances to each other.

If you find that creepy, Anonymous, I'm sorry, but it seems a fact of life to me.

A simple example: I think most people on holiday would be delighted to find a deserted beach that they could enjoy with their friends or family -- rather than a beach so crowded that you can hardly walk without stepping on someone, and litter bobbing around in the sea.

More people -- more crowding -- means a lower quality of life for the members of those crowds. Regardless of the quantity of food processors and mobile phones that they churn out at work.

I have no wish to be the only person left on the planet (that would be misanthropic!). But if I found an alternate world with (say) a tenth of our world's population, it would look attractive to me: I think it'd be a better place to live. According to Wikipedia, that was the level of our world's population in about 1700 AD.

Jonathan said...

P.S. In case anyone gets the wrong idea, I'm not yearning for a return to the technology of 1700 AD -- though the owner of this blog might be relatively comfortable with it.

If time travel becomes available, I'd rather go forward, and hope that a future century will see a return to earlier and more comfortable levels of population -- combined with a higher technology than we have now.

Arthur B. said...

More people means more pollution, more noise, more traffic, housing more expensive and harder to find, and so on and forth.

What you are describing is a city, like Manhattan. The density here is 26,000 / km². The density of the current population on earth is about 43 per km². More people means more cities, not necesseraly more crowded cities.

The reason cities are crowded is not because of overpopulation but because concentration of people provide greater advantages to them than discomfort. There is plenty of available land.

A simple example: I think most people on holiday would be delighted to find a deserted beach that they could enjoy with their friends or family -- rather than a beach so crowded that you can hardly walk without stepping on someone, and litter bobbing around in the sea.

Beaches are generally handled by the State which creates a tragedy of the common, dirty, crowded beaches. Most beaches in the world are actually desertic, of course they're far from cities, but since you don't like the crowd that's hardly an issue.

But if I found an alternate world with (say) a tenth of our world's population, it would look attractive to me: I think it'd be a better place to live.

You would have a much lower level of life. All the things that you use every day had to be produced somehow think about it. Less population means it's less likely that someone in a given period will invent the microchip. As I said labor is scarce, not resources, you would sit on a world with vast amount of resources and not enough people to do something useful with it.

I urge you to take a look at, they take pictures at every point on the planet with integer latitude / longitude coordinates. In this statistical sample, you hardly notice any human presence.

Michael Roberts said...

Labour is not currently scarce. Companies produce propaganda that it is scarce in order to convince governments, ammongst other groups, to make policies which will increase the labour force anyway. This allows the companies to have the pick of a bigger pool, which allows them to exploit the workers more intensely.

Manipulation of unemployment statistics helps make it look like the unemployment rate is low. Most unemployed people I know do not qualify as "unemployed" because of situations they've been forced into by former employers who were using a loophole in Canadian labour legislation to avoid labour standards.

Vicious cycle, eh?


Arthur B. said...

If labor were not scarce it'd be free. I guess you must have hundreds of house servants.

(n.b I said resources are not scarce, I meant, not as scarce as labor)

Anonymous said...

Jonathan, the average non-farmer today lives a much less crowded life than 50 or 100 years ago. It used to be common for large families to live in tiny, tiny apartment buildings. The average home size has steadily increased. Obviously a lot has changed besides an increase in population.

More population means more brains, which means more art and science and technology. It also means larger markets, which lowers production costs and makes a greater variety of goods available.

Of course if you consider only the disadvantage of population and ignore the advantages, you get a clear conclusion. But what's the point?

montestruc said...

ll wrote:

"is co2 heavier than o2? in this sense , is the co2 as abundant as on the surface?"

This probably has some truth to it, however the effect of H2O condensing out of the mix at temperatures seen above about 8,000 feet above sea level is much stronger effect than turbulent mixing which will keep the gasses pretty well mixed together. That is unless you have a strong mechanism to seperate them, like snowing out. So I expect that some such effect exists, but it is probably small.

CO2 does not snow out till you get to -78.5 C which is not seen at any altitude in the earth's atmosphere. The temperature of the earth's atmosphere bottoms out at -56.5 C in the stratosphere then goes up with altitude.

Jonathan said...

Perhaps we can agree on the fact that an increase (or decrease) in world population has both advantages and disadvantages. Whether you prefer an increase or a decrease therefore depends on your subjective evaluation of the advantages versus the disadvantages. It's a matter of personal preference.

Arthur_B: my impression is that many city-dwellers live in cities not because they really like cities, but because most of the jobs are there. This may well change. I think it's already changing. I work for a large company, but I live in a small town and work from home by e-mail.

As for the scarcity of labour, we now have machines to make things for us. Their productivity is considerable and continues to grow. More and more, people work in services because they're not needed in manufacturing.

I think a future world with a smaller population could get along perfectly well.

Even technological progress is computer-assisted and will be increasingly so as machine intelligence increases.

Anonymous: re the suggestion that natural selection will get humanity breeding again, I point out that natural selection takes a long time. In a shorter time than that, natural selection will cease to apply to our species, because of progress in genetic engineering.

I think economies of scale were a concern of the Industrial Age and are gradually becoming less important. It's no longer the case that you can have a car any colour you like as long as it's black.

I could go on, but I'm becoming embarrassed by my own verbosity.

Anonymous said...

"It's a matter of personal preference."

Only if your preferences are really extreme, e.g. if the 'advantages' of a large population are not advantages at all for you, because you don't care about them.

No, it's primarily a question of facts, not preference. Unfortunately, we can only guess at what the facts are. You have your guesses and I have mine.

"Anonymous: re the suggestion that natural selection will get humanity breeding again, I point out that natural selection takes a long time."

Think of it like an epidemic. After a disease sweeps through a population, the people who are left are those who have some resistance. There is enough diversity that a total wipeout is unlikely. In this case, the "disease" are the environmental changes that lead to low fertility. The population will rebound when the descendents of those are fertile under modern conditions begin to dominate.

Synova said...

There are many truly beautiful places in this country with small populations.

The problem is that you can't *work* there.

Since this has nothing to do with people not wanting to work, why do you think (I suppose I'm asking Jonathan) that less population would only affect crowding and noise and pollution? Or are you assuming that a lifestyle reduction is acceptable? And if a lifestyle reduction is acceptable why not do that now? You can quite easily. I can point you at a lovely little town with friendly people, clean air, nice green lawns and forests and the prettiest lakes you will ever see.

And no jobs.

Jonathan said...

Anonymous: I suppose homosexuality is a particularly definite example of what you call 'reproductive failure'. But it shows no sign of dying out. Apparently natural selection doesn't work on it.

Heterosexual couples often decide to have no children, or only one child, because children -- although lovable and fun in some ways -- are a lot of trouble and expense. I don't think that's likely to change any time soon. (I have one child, myself.)

Synova: "... why not do that now?" I have done it now. I live in a small town and work by e-mail. I experience the unpleasant consequences of population density mainly when I go elsewhere. Though even this small town is expanding fast...

Arthur B. said...

Jonathan, by using e-mail you are enjoying the benefits of a large population highly concentrated in such place. With a low, sparse population the division of work would be much less, the overall productivity dramatically lower.

It's like Amish's crops. They implicitly rely on a huge concentration of roads, trucks, oil refineries and the like to be sold.

Jonathan said...

Arthur, I don't follow your argument. E-mail involves electricity, computers, and communication. These require no enormous workforce. If world population declines gradually over a long period, I think people will have no trouble in maintaining and improving existing systems.

Hypothetically, if we imagine the magical disappearance of the human race, leaving only two people behind, I think they could still contrive to communicate with each other by e-mail, as long as they knew what they were doing and lived reasonably close to each other. Small-scale electrical generation is feasible; in the event of computer breakdown, there would be plenty of spare computers lying around. If the two people insisted on living on different continents, setting up a connection would admittedly be a challenge.

Regarding low-populated areas of the world as it is, I've read that residents of the South Pole have access to e-mail.

Raphfrk said...

Two people wouldn't be able to maintain a tech society, no matter how smart they are.

I guess some serious automation might allow it, but then they aren't actually the ones doing the maintaining. They are just living off the labour of the now dead large population.

There is only so much 'active' knowledge that you can fit in a person's head. Society splits all the required knowledge over many pepople.

If you drop the population, then each person has to know more about how to run the society. Each person has skills in more areas than before, but is less skilled in any one of them. This slight shift from specialist to generalist reduces their efficiency.

A drop by 90% probably wouldn't have world ending effects. However, there would come a point where we couldn't store all the knowledge in active memory to keep things going.

Shifting from 100 people with specific knowledge to 10 isn't that major, shift from 10 to 0 is.

Also, the rate of scientific and other developments would decrease. If a society can support 5% of its population doing research, then a lower population society organised in the same way would still only be able to support 5% of its population.

This means that development is slowed.

Michael Roberts said...

No, I don't have hundreds of house servants, I work for less money than the time is worth to me becasue I can't get a job that is worthwhile, and I'm prevented (mostly by laws, but in some cases by population density) from doing the things which would allow me to be self-sufficient.

So, basically, I *AM* a free house servant, a certain percentage of my offical working time.

If labour is not scarce, how come companies can afford to employ such large percentages of their workforce in jobs which are not concerned with production?

A certain percentage of my work time is devoted to writing reports to my government. Although a recent change is improving the situation, much more useful statistics could have been compiled in a much more efficient manner.

At government-sponsored companies and organizations, whole full-time-equivalent positions are devoted to doing utterly useless number cruching which anyone and everyone involved can see could be done more efficiently and effectively. The same applies to completely private comanies I've been involved with, but I've been involved with less of those.

I second the opinion about reasons why people live in cities. It certainly applies to me. As I mentioned previously, I lack the resources to persue an exit strategy. I will point out that I'm poorish, but not ridiculously so. I am far from being alone in this.

I also agree that in using email, we are enjoying the benefits of a population of a certain size. But I would agrue that due to the vast ammount of wasted person-hours, we are experiencing the benefits of a *much* smaller population than we actually have, while still suffering most of the problems. Which ain't such a great way to go about things.


Michael Roberts said...

Uh... actually, most of my job is very worthwhile in and of itself -- that's kinda important to me... it's just not an even deal with regards to compensation for the lost hours.

Sorry about the poor phrasing up there.

Anonymous said...

"Heterosexual couples often decide to have no children, or only one child, because children -- although lovable and fun in some ways -- are a lot of trouble and expense. I don't think that's likely to change any time soon. (I have one child, myself.)"

It will chance about as fast as the occurance of plague resistance genes during a raging plague. Which means: as fast as genetic chance can get.

I find it quite incredible that everyone (the above AP is the first exception ive ever come across) seems to accept the decline in fertility associated with recent unprecedent wealth a cosmological given constant. Its a phenomena thats going to die out like rats on a sinking ship if anything we know about evolution is true.

Andrew said...

Dyson is bright, but he's out of his field. Here is a concise refutation of Dyson's main points, from the same magazine: