A Few Things Ill Considered

A layman's take on the science of Global Warming featuring a guide on How to Talk to a Climate Sceptic.

Friday, June 16, 2006

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Al Gore's "An Inconvenient Truth": How True? How Inconvenient?

An Inconvenient Truth

How True?

According to the climate scientists at Real Climate, Gore gets it right.

How well does the film handle the science? Admirably, I thought. It is remarkably up to date, with reference to some of the very latest research. Discussion of recent changes in Antarctica and Greenland are expertly laid out. He also does a very good job in talking about the relationship between sea surface temperature and hurricane intensity.

How Inconvenient?

Pretty much so, judging by the reaction of the Right Wing spin machine. Since they are all pretty much the same, let's pick one because he shares my last name (but no relation as far as I know!), Glenn Beck.

His reaction to the films description of the threat of rising sea levels?


This is what would happen to Shanghai. Does anybody really care? I mean, come on. Shanghai is under water. Oh, no! Who's gonna make those little umbrellas for those tropical drinks?
So much for morals. How about his take on the science?


Now, if Al Gore's projection is right about the CO2 level going as high as he says it will, then the temperature here on planet Earth will be about 400,000 degrees. We'll be the sun; we'll be the frickin sun. But that's a huge "if."

(It's huge alright, but I have another idea of just what it is...)

Since he proves to be no match for the message, what does he think of the messenger?

See, when you take a little bit of truth and then you mix it with untruth, or your theory, that's where you get people to believe. You know? It's like Hitler. Hitler said a little bit of truth, and then he mixed in "and it's the Jews' fault." That's where things get a little troublesome, and that's exactly what's happening.

Too bad the beltway pundits don't respect Godwin's Law, think of all the extra-strength aspirin we could save.

Of course, RC's endorsement is swamped by crap like Glenn Beck's, but for myself, until I can get to see it, I will take the vapidity and ad hominem nature of the attacks as evidence that this film does a good job.

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posted by coby @ 6/16/2006 01:10:00 PM  

36 Comments:

  • At June 16, 2006 4:17 PM, Blogger Heiko said…

    http://www.indyweek.com/gyrobase/Content?oid=oid%3A33011

    http://www.climatecrisis.net

    I have read Real Climate's review and I have not watched the movie, but as happens there's an official website for the movie. Look at this passage:

    "If the warming continues, we can expect catastrophic consequences.
    Deaths from global warming will double in just 25 years -- to 300,000 people a year.
    Global sea levels could rise by more than 20 feet with the loss of shelf ice in Greenland and
    Antarctica, devastating coastal areas worldwide.
    Heat waves will be more frequent and more intense.
    Droughts and wildfires will occur more often.
    The Arctic Ocean could be ice free in summer by 2050.
    More than a million species worldwide could be driven to extinction by 2050."

    Notice how there are two years mentioned there (2025 and 2050), but none for when we might expect 20 feet of sea level rise.

    And look at the review above which got quoted approvingly on the Future Geek blog:

    "Will the approaching environmental catastrophe it warns of be averted, or will we soon witness places like the Outer Banks, Manhattan, the Bay Area and Bangladesh sliding beneath the waves with the same kind of dumbstruck horror provoked by the TV images of Hurricane Katrina?

    ...

    Western Antarctica and Greenland already are melting fast enough that one--or both--could collapse into the ocean. If that happens, it would likely raise sea levels several feet in a relatively short amount of time. This is where we hit the kinds of doomsday visions suitable to Hollywood horrormeisters: entire cities swamped by rising tides, the widespread submersion of luckless lowland locales like Florida and Holland, refugees on the Indian subcontinent numbering upward of 100 million.

    Here the mind balks, and we wonder if we're being oversold. Perhaps. But what if Gore is right and we may have only 10 to 20 years to reverse the pattern?"

     

  • At June 16, 2006 4:53 PM, Blogger coby said…

    I would expect that the timeframe for melting is clearly stated in the actual film. It is highly uncertain, but I have not heard any credible voice saying that won't take centuries to a millenium.

    It is the same with the hurricane images, sensationalized in the trailer for sure, but as long as it is not misrepresented in the film I am not too worried about it.

    James Hansen has been saying alot recently that he thinks we have about 10 years to get started on mitigating actions.

    Future Geek has volunteered some help in layout and blogger features and tricks, so that should not be taken as endorsement of everything he has blogged about, I only glanced through a bit.

     

  • At June 16, 2006 5:42 PM, Blogger Heiko said…

    I can't say much about the movie itself, because I haven't watched it. But I can criticise the official web page, which I think is alarmist and misleading.

    What's so hard about stating the IPCC range (9-88 cm by 2100) and then going on to say that over the next few hundred years 20 feet might be added from Greenland and WAIS?

    I think the way the paragraph is done at the moment easily misleads the uninitiated into thinking it might be 20 feet by 2050 or even 2025.

     

  • At June 17, 2006 9:32 AM, Anonymous Anonymous said…

    The time frame isn't clearly stated in the film. It's a threatening possibility, not a known fact. Gore introduces the concept of abledo and shows how feedback loops could lead to dramatic reductions in ice, especially in the Arctic, and he mentions glacial earthquakes in Greenland, but he doesn't put a timeline on the melting of the ice sheets.

    Ronald Bailey of Reason magazine picked up on this. Bailey admits the deniers have damaged their own cause with ridiculous attacks on Gore (for instance, William Gray comparing him to Hitler).

    But in a recent essay in Reason magazine, he tries to argue that Gore overstated the threat. You might want to take a look at the piece; it's dismissive, but not stupid, and Bailey is honest about his affiliations or lack thereof, unlike a lot of ExxonMobil hacks.

    Bailey admits that the climate is changing and (if memory serves) that we humans are responsible. He essentially looks at Gore's data and shrugs, which to me seems inadequate. But as thin as his piece is, it's still the best argument I've read against Gore.

     

  • At June 17, 2006 3:28 PM, Anonymous Anonymous said…

    here is Ron Bailey's review,
    http://www.reason.com/rb/rb061606.shtml

    I will confirm that Gore does not mention when any sudden degalciation might occur in Greenland and the Antarctic, in a seperate interview, Gore describes this as a "wildcard".

    sam

     

  • At June 17, 2006 4:00 PM, Blogger Heiko said…

    "what is at stake [is] our ability to live on planet Earth, to have a future as a civilization."

    Did Gore really say that? Either that's terribly loose language or he's actually saying that a Venus type scenario is "at stake".

    http://achangeinthewind.typepad.com/achangeinthewind/2006/06/global_warming_.html#more

    And that's a review approvingly quoted by Kit Stolz.

    Mankind and its governments must begin immediate action to halt and reverse it. If we do nothing, in about 10 years the planet may reach a "tipping point" and begin a slide toward destruction of our civilization and most of the other species on this planet.

    After that point is reached, it would be too late for any action.

    These facts are stated by Al Gore in the documentary "An Inconvenient Truth." Forget he ever ran for office. Consider him a concerned man speaking out on the approaching crisis. "There is no controversy about these facts," he says in the film.

    I find that pretty hard to swallow. Gore said that if we don't act within 10 years our civilisation may come to its end, that any action would then become futile, and that that is the scientific consensus?

    James Hansen has been saying alot recently that he thinks we have about 10 years to get started on mitigating actions.

    But what does he mean by that? Surely not that Kyoto will make the difference between Earth becoming Venus and salvation.

    I suspect he's talking about avoiding 2C with some measure of certainty.

     

  • At June 17, 2006 4:39 PM, Blogger coby said…

    Heiko,

    I think there are many degrees of catastrophe that fall in between the destruction of civilisation as we know it and turning Earth into Venus. It does not require that all life come to an end for us to lose what we have, as a species, developed over the last few thousand years. It does not even require that for our species to go extinct. I think the best historical analogy of how bad things can get for the whole race and have gotten for various societies in the past is the history of the Polynesians on Easter Island.

    Also, between where we are now and the lose of civilisation are similarily many degrees of catastrophe. The premature deaths of 100's of millions, even billions, the lose of cultures, the cessation of progress, the loss of the luxuries we take for granted. All of these, though not equal in degree of catastrophe, are undesireable. And these things are in fact at stake.

    I would be surprised if Al Gore ever claims that a 10 year tipping point to destruction of civilisation is an uncontroversial fact. He seems to have been very careful in other areas, such as hurricane Katrina, again according to RealClimate.

    Re James Hansen: he has alot of suggestions, relying on Kyoto alone is not one of them. IIRC, he talks about reductions in black soot and methane as easier and more immediately effective actions to take. And again, a Venus scenario is a red herring. Let's just consider things like droughts for 100's of millions in China if the Himilaya became glacier-less and the beginning of the end of the Greenland Ice Sheet, regardless of how long it takes to finish melting. These are the kinds of consequences that may well be unstoppable after 10 more years of doing nothing. And, yes I think you are quite correct that 2C is becoming the number to avoid.

     

  • At June 17, 2006 4:52 PM, Blogger Glen said…

    I would expect that the timeframe for melting is clearly stated in the actual film.

    Nope. In the actual movie Gore doesn't give any specific time by which water level would rise 20 feet. The film (just like the trailer and the website) gives viewers the false impression that this event is imminent. What Gore does is put it in terms of ice loss. It's "if we were to lose all of this ice over here, or half of this and half of that over there...then water level goes up 20 feet." Without any dates, but with computer-graphic visuals showing the waters encroaching on the buildings of today's New York and elsewhere.

    I found that one of the most dishonest moments of the film. It made it hard for me to maintain willing suspension of disbelief for Gore's other claims.

     

  • At June 17, 2006 6:11 PM, Blogger coby said…

    I found that one of the most dishonest moments of the film

    C'mon, Glenn, let's hear about some others. This is the single legitimate objection I have heard (I am taking your word for there being no time frame supplied). You want us to accept your characterization that the film is in general dishonest, provide some evidence. One potentially misleading presentation in a 90 min discussion does not merit that criticism.

    And BTW, so far nothing I have seen credibley attributed to that film is "Gore's claim" rather it seems to be the well supported conclusions of the current science.

     

  • At June 18, 2006 2:44 AM, Blogger Heiko said…

    Coby,

    Jared Diamond's version of the Easter island story is quite controversial.

    http://www.livescience.com/history/060309_easter_island.html

    http://news.mongabay.com/2005/1206-easter_island.html

    http://peakoildebunked.blogspot.com/2006/03/260-more-evidence-debunking-eco.html

    "The collapse was really a function of European disease being introduced," Lipo said. "The story that's been told about these populations going crazy and creating their own demise may just be simply an artifact of [Christian] missionaries telling stories."
    ...
    "It fits our 20th century view of us as ecological monsters," Lipo said. "There's no doubt that we do terrible things ecologically, but we're passing that on to the past, which may not have actually been the case. To stick our plight onto them is unfair."

    http://www.agron.iastate.edu/courses/agron342/diamondmistake.html

    And Jared Diamond has also said this:

    In particular, recent discoveries suggest that the adoption of agriculture, supposedly our most decisive step toward a better life, was in many ways a catastrophe from which we have never recovered.

    Getting back to the topic of climate change. I know that the "end of civilisation" may for some people be the time when we kill off a species of Arctic moss, to be a little flippant.

    But with the phrase "our ability to live on Earth", wouldn't you say that can be interpreted as Earth becoming Venus? I don't think that's a red herring at all. It's a plain reading of what "our ability to live on Earth is at stake" means. I think anyway, and admittedly I am not a native speaker.

    In truth there's very little we will do over the next ten years that'll differ much from what we have done over the last ten years. Nobody is proposing 80% nuclear in 10 years for the US, renewable standards are for something like 20% by 2020 in the boldest proposals there are, doubling CAFE over ten to twenty years as I think has been proposed by Kerry will have very little effect on CO2 emissions by 2016 (due to slow vehicle turnover in particular).

    I just don't see us doing anything that'll move greenhouse gas emissions much from a BAU path, and whatever little is at stake in the policy debates in the OECD is small compared to other emissions uncertainties (ie we may have 25% more CO2 or 15% or 40% over the next 10 years and that'll mostly depend on things like oil prices/demand and coal use in places like China, and very little on whether CAFE gets raised by 10 mpg in the US, or whether a renewables standard of 20% by 2020 gets enacted).

    And the reason for that isn't the boiling frog syndrome, but the fact that the public is not convinced that climate change of 2C must be avoided, when this involves petrol prices at 10 Dollars a gallon say (some 80% of Germans in a recent survey replied to a fuzzy question about global warming that it was "real", whatever that exactly means, but only 15% said a substantial increase in eco-taxes was justified).

    The level of mitigation over the next 10 years has very little to do with whether Greenland's ice sheet will melt or not. It does entirely depend on emissions beyond 2016. Whatever mitigation measures are enacted before 2016 will not save the ice sheet, if we continue to emit heavily from coal into the 23rd century, and whatever we do emit before 2016 can be mopped up again over the next two centuries. That needn't be high tech either. Burying char coal will do if all else fails, and that's a rather well established technolgoy.

     

  • At June 18, 2006 11:30 AM, Blogger coby said…

    And Jared Diamond has also said this:

    In particular, recent discoveries suggest that the adoption of agriculture, supposedly our most decisive step toward a better life, was in many ways a catastrophe from which we have never recovered.

    Interesting article, it really questions alot of thing I have previously taken for granted, thanks. As a sceptical person, shouldn't you take this idea seriously, even if it challenges things that you perhaps have taken for granted? I ask because you presented the quote seemingly as fait accompli evidence of Jared's unreliability. What is wrong with his evidence?

    Thanks for that article about Easter Island, Heiko. I have requested a reprint of the paper reported on from one of the authors and hope to be able to read it soon.

    I categorically do not agree that saying we human's are threatening our ability to live is equivalent to believing that the loss of all life on earth is a possibility, which a Venus scenario clearly entails. I seriously doubt you will find anyone thinking this either. I believe with extreme confidence that no matter what humans do, including causing a mass etinction event the like of which has never been seen, detonating every nuclear warhead on the planet and polluting the land a ocean to the point we could only remain here in spacesuits, doing all this at once, life would still survive on planet earth.

    I can only restate my point that there are many undesireable degrees of disaster we would be insane not to avoid before reaching such a point.

     

  • At June 18, 2006 12:46 PM, Blogger Heiko said…

    Forgive me if I leave Jared Diamond's article aside for the moment.

    I am not sure what to make of your reply. Venus is, as far as we know entirely lifeless, and in all likelihood, so is Mars. And the extinction of humanity need not mean the extinction of all life.

    So, I'll readily admit that "our ability to live on Earth", isn't the same as the extinction of all life, which seems to be what you associate with this loose term of Earth going Venus.

    What I think "our ability to live on Earth is at stake" means, is the survival of humanity is at stake, and I am willing to use the term Earth going Venus for that, being perfectly aware of the fact that humanity could go extinct while some other life (and be it only bacteria) survives.

    Of course there are many degrees of disaster short of human extinction or the extinction of all life.

    But that doesn't mean our survival as a species is at stake. You aren't really saying that it is???

    And if it isn't, why use such apocalyptic language?

    Let me add something on your thoughts about drought in China killing hundreds of millions. As far as I know, 50 million Chinese perished in the 60's without any drought. In the 1930's, likely without anthropogenic climate change being much of a factor, the dust bowl devastated American agriculture like no other drought of the 20th century, and that with quite some margin. Yet, there wasn't much death.

    A rich China can buy in grain, just like most of Northern Africa and the Middle East do, an area where hundreds of millions of people live under permanent drought conditions.

    China also can, and currently does, invest heavily in water projects. Some environmentalists demonise these projects, be it Assouan or 3 Gorges, and completely forget about the benefits.

    The way to deal with droughts and floods is to build large water projects that keep the water in reservoirs, ready to be released for irrigation. In addition, huge amounts of electricity can be produced. Hydropower is responsible for 1/6th of world electricity production (roughly the same as nuclear, the two together account for something like 95% of emissions free electricity generation). 3 Gorges alone will when completed generate more electricity than all of the world's wind turbines did together in 2005.

    And electricity matters, to enable air conditioning, which is by far the most effective way to deal with the health impacts of heat waves, and for many other applications from refrigeration to cooking, that have massive health impacts. Did you realise that burning of traditional biomass is among the top ten causes of disease, and particularly hits children under 5 (children who are exposed to fumes from the burning of dung and firewood indoors)?

     

  • At June 18, 2006 3:04 PM, Blogger coby said…

    that doesn't mean our survival as a species is at stake. You aren't really saying that it is?

    Well, we were discussing what Al Gore had said. But I won’t be cagey about my own view. I do believe that there is a very small, but still non-zero, probability of the extinction of our species. We are not invincible, nor are we independent of the food and water services provided by the biosphere. I am hopeful that technology will find ways to replace oil as an energy source but I do not take it as a matter of faith that it will. Nor do I take it on faith that technology will feed us if the biosphere no longer can, especially if we have severe energy constraints placed on us. If emissions are not reduced, it is very likely to certain that humanity as a whole will suffer great hardships around the globe from famines, droughts, wars...all the good stuff. It is well within the realm of possibility that the progress of civilization will be tremendously set back. It is most probable that life on the planet will falter and retreat in a big way, but I'm confident it will not come close to disappearing as it did not in other mass extinction events. It is very hard to predict how badly this mass-extinction will hurt the bioshpere but there is little reason to believe it will not be among the worst such extinctions we are aware of. But life will go one, in a few hundred thousand years it won't have mattered all that much.

    We will not find it easy or pleasant to live.

    Your examples about previous droughts are appropriate historical lessons, though I am really not sure what you are trying to illustrate by them. That it’s not that bad when it happens? No, of course not, but I think you ignore the real threat about a global problem. It is much worse when these things happen all over the place all at once. It does not matter how rich you are as a country if there is no grain to buy.

     

  • At June 18, 2006 5:03 PM, Blogger Heiko said…

    What I don't think is possible is that climate change alone will turn the planet uninhabitable for us. I also think that that's on a sound scientific basis, and that therefore neither you nor Gore would say otherwise.

    Climate change might be a decisive contributing factor leading to nuclear war and God knows what, and if you think Al Gore was referring to that, I suppose I could imagine him saying it.

    Neither of us has watched the movie, so I'll let this particular point be. I do think that the official website of the movie is unduely alarmist. We may disagree there, but in actual climate policy we may not be that far apart, so the disagreement may not matter nearly as much as it might appear at first glance.

    I used to be very interested in "peak oil", still am marginally. I spent a huge amount of time posting on the energy resources yahoo group (maybe between 1999 and 2003, might be a few hundred messages on the topic). I am still very interested in energy related topics, not least because I work in the area (bioenergy being my research area). But I now completely reject the notion that oil cannot be replaced. I don't think that's got anything to do with faith. It's based on a rational assessment of what we use oil for at the moment and what means we've got at our disposal with present technology to displace oil in these uses.

    I think a well developed world economy can easily adapt to a changed climate, and particularly agriculture, through a combination of CO2 fertilisation, large water projects and use of new crops.

    If I believed widespread famine was likely, I'd be a lot more alarmed than I am. As is I think that climate change will make famines less likely, rather than more likely, and in any case the primary determinant will not be the weather, but good economic management. Famines today happen because of corruption or mismanagement. To change that the planet would have to turn into a huge desert and there is no credible climate change scenario for that. I consider it essentially impossible for climate change to be sufficiently bad for it to cause world famine in spite of good economic management.

     

  • At June 19, 2006 3:37 AM, Blogger Heiko said…

    I wanted to think a little bit before saying anything more about Jared Diamond's article. The main reason I quoted that was because it shows his attitude or general world view, if you like.

    Without agriculture, 99% of people today wouldn't be alive, we'd still be hunter gatherers. I couldn't be writing this, there'd be no computers, there'd be no system of writing even.

    To call agriculture the greatest mistake mankind's ever made shows very little appreciation for what we've got today, and a pretty romantic view of the stone age.

    The Malthusian argument isn't new. It isn't in much dispute either that up to surprisingly recent times, progress was mostly measured in human numbers, the size of empires and the addition of new technologies. And even that wasn't without setbacks, like the plagues or the dark ages following the end of the Roman empire. Malthus argued that extra food would just bring about extra mouths to feed up to the point where war, disease etc.. would bring population back into balance and life would be just as miserable.

    Malthus's argumentation was just as true for the stone age as for agriculturalists. If food was tight, they'd have to kill neighbouring tribes or some of their own. According to some estimates, 50% of adults in the stone age died violent deaths.

    Overall, life expectancy was low in the stone age and stayed low until nearly 1900.

    http://en.wikipedia.org/wiki/Life_expectancy

    Jared Diamond makes a mountain (or should I say deep valley?) out of a minor dip.

    In the end, life was pretty much as short, brutish and nasty in the stone age as in the bronze age or the Middle Ages.

     

  • At June 19, 2006 7:07 AM, Blogger Heiko said…

    http://demography.anu.edu.au/jpr/issues/20-2/20-2_153-168.pdf

    The above is a good review paper on the "neolithic mortality crisis".

    In summary there is good evidence that certain diseases became more prevalent. The evidence that overall mortality and fecundity changed much is rather less certain. And without some self restraint on the part of paleolithic peoples, the Malthusian argument and glacial population dynamics inevitably point to high fecundity equaling high mortality. Or in other words, if Neolithic diseases didn't do them in, other diseases or other causes of death did.

     

  • At June 19, 2006 8:05 AM, Anonymous Anonymous said…

    I think the ‘survival as a species’ point is not really dependent on earth turning into venus or anything approaching that limit.

    The problem with humanity is that we massively exceed the ‘natural’ carrying capacity for a species and our present numbers are maintained solely through our application of technology.

    Now, already in some parts of the world, it is feared that the next conflicts could result over water. If climate change starts to make areas uninhabitable, we could face the start of mass migrations, which western societies will not accept, faced with people who have the choice of migrate or die. We’re already becoming very anxious about immigration. Can societies withstand this type of stress?

    If food production is disrupted what happens then? We in the west will be OK for sure, but see above. Ditto water, ditto sea level incursion.

    The ride can get very bumpy if a wheel comes off.

     

  • At June 19, 2006 10:54 PM, Blogger coby said…

    Heiko,

    This whole side topic is very interesting, but I doubt I will be able to discuss it very intelligently, I had never heard any suggestion before that agriculture was anything other than the Great Enabler of all humanity's wonders. It is an intriguing notion, the evidence seems to make it worth another look. I note in your objections you are just basically saying he is wrong without saying why you are sure! I also noticed some of the things you brought up are very recent developments, eg improved life expectancy and technology. Couldn't one attribute alot of this to the oil era?

    Again, this is all quite new for me.

     

  • At June 20, 2006 2:29 AM, Blogger Heiko said…

    I had never heard any suggestion before that agriculture was anything other than the Great Enabler of all humanity's wonders.

    You must have heard of Malthus. He even brought up the issue of disease and dense settlements.

    I note in your objections you are just basically saying he is wrong without saying why you are sure!

    You aren't being very concrete here ;-)

    I agree with the notion that some causes of mortality went up. For some diseases linked to dense settlements the evidence for that seems quite convincing.

    The case that life expectancy went down is much weaker. Basically, in a virtually static population birth rate per 1000 must equal death rate per thousand. So the death rate can only move, if the birth rate moves.

    Life expectancy for paleolithic people could only be higher than for neolithic agriculturalists, if they had lower birth rates.

    If both neolithic and paleolithic people had birth rates of 50 per 1000, then they also both had death rates of 50 per thousand and therefore life expectancy of around 20 years, and the only difference would be the causes of the mortality.

    I also noticed some of the things you brought up are very recent developments

    The improvements in life expectancy are indeed very recent. As said, up to about 1900 Malthus's argument that more food would just mean more people held up quite well.

    The impression of steady progress is mostly to do with
    a) population growth
    b) accumulation of technology, such as the ability to produce bronze or steel, or paper making, or the wheel etc...

    Couldn't one attribute alot of this to the oil era?

    Depends on what you mean by that. Certainly rising oil production coincided with rising life expectancy. Both happened mostly over the 20th century.

    Oil can be substituted, and most oil uses aren't essential and have little to do with health. It won't kill anybody to move to within cycling distance of work, it might even do their health some good!

     

  • At June 20, 2006 1:57 PM, Blogger coby said…

    The case that life expectancy went down is much weaker. Basically, in a virtually static population birth rate per 1000 must equal death rate per thousand. So the death rate can only move, if the birth rate moves.

    Life expectancy for paleolithic people could only be higher than for neolithic agriculturalists, if they had lower birth rates.


    If both neolithic and paleolithic people had birth rates of 50 per 1000, then they also both had death rates of 50 per thousand and therefore life expectancy of around 20 years, and the only difference would be the causes of the mortality.

    Heiko,

    I don't understand how you arrive at your conclusions about life expectancy from birth and death rates alone. Total population must be in there too. ie given a fixed birth and death rate, life expectancy can vary depending on the total population.

    I would assume that reconstructions of past life expectancies would come from anaysis of remains, in fact can only come from this. Then from this and estimates of population size coming from other archeological evidence you could infer birth rates. As you say, if population is stable then birth rate must equal death rate.

    I think alot of the attribution of progress to agriculture rests on the notion of more time free for other pursuits. If this is not true, then why think that progress could not have come without agriculture?

    But perhaps a strong case can be made for the urbanization driving cultural and technical advancement, which in turn would depend on agriculture.

     

  • At June 20, 2006 3:19 PM, Blogger Heiko said…

    Death and birth rates are commonly expressed as births or deaths per 1000 population.

    Suppose there are 50 births every year in a static population of a 1000 people, and everybody dies at exactly 20, then there are 50 people age 1, 50 people age 2 and so forth adding up to 1000.

    If half the population dies at age 0 and the other half at 40, then there are 25 people aged 1, 25 aged 2 and so forth again adding up to a 1000.

    No matter how you slice it, a death rate of 50 per 1000 means a life expectancy of 20 years in a static population.

    --------------------------

    If you look at that very good review paper on the neolithic mortality crisis (I only undug that after posting on Jared Diamond's article, I first came across his article a few years back and gathered a lot of information and posted it on the energy resources yahoo group. The search function in there is so hopeless that I can't seem to recover it, so I had to find some new references), you'll see that the evidence from skeletons is difficult to interpret and contradictory, and a lot of the impetus for supposing a mortality crisis comes from studies on the relationship between some diseases and population density.

    ---------------------------

    The evidence for there being different levels of leisure time is pretty circumstantial.

    At any rate, I think that specialisation and economies of scale are much more important factors for technological progress.

     

  • At June 20, 2006 4:40 PM, Blogger coby said…

    No matter how you slice it, a death rate of 50 per 1000 means a life expectancy of 20 years in a static population.

    Only if your total population is 1000. Think of how life expectancy is expressed, it is not expressed as per thousand, it is a property of a total population.

    I hope to look at your other references soon.

     

  • At June 21, 2006 1:00 AM, Blogger Heiko said…

    But that doesn't make any difference, if the total population is a million, you just multiply all numbers. So, death rate of 50 per 1000 means 50,000 deaths etc.. As the life expectancy is an average it isn't impacted by overall population size.

     

  • At June 21, 2006 10:18 AM, Blogger coby said…

    Ok, sorry, you're right.

     

  • At June 21, 2006 4:36 PM, Blogger Glen said…

    I wrote: I found that one of the most dishonest moments of the film

    Coby wrote: C'mon, Glenn, let's hear about some others.

    Okay, sure. In addition to strongly implying an imminent 20-foot sea-level rise:

    Gore claims if you heat a frog slowly, it won't jump out of hot water. (this is a false urban legend)

    Gore claims you can easily see the impact of the US Clean Air Act in ice cores. (nobody seems to know where he got this idea from)

    Gore says we have bad cars because even China has higher mileage standards. (Ignores that all but the smallest Chinese cars don't yet meet their own (recently-announced) standard, and ignores that extant Chinese cars tend to be worse in other metrics such as reliability and safety.)

    Gore implies a scientific consensus supports the contention that warming is causing more and stronger hurricanes. (it doesn't. Maybe someday it might, but it doesn't now.)

    Gore implies that disease outbreaks and "invasive non-native species" are a warming-related phenomenon. Even Realclimate dings him on that one.

    BTW, it's just "Glen". One "n".

     

  • At June 21, 2006 6:16 PM, Blogger coby said…

    Thanks Glen, sorry for the mispelling.

    Frogs: who cares?!? It's not a film about amphibian behaviours.
    Chinese cars: bit of a not pick that one. Also not to do with climate.
    Hurricanes: I need to see a transcript or hear it for myself. It is justifiable to say there is scientific evidence, and easy to confuse that with there is a consensus.
    Disease and invasive plants: I have heard that elsewhere, so ok.

    Still doesn't merit dissing the whole film as dishonest, my impression is it is quite dense with information, and apparently the vast majority if it is accurate.

     

  • At June 21, 2006 7:55 PM, Blogger Will said…

    Okay, sure. In addition to strongly implying an imminent 20-foot sea-level rise:

    You know, I saw the movie, and from what I remember, it didn't seem like he was 'implying' anything. First he showed how much the ice has melted from Antarctica over the past few years. Then he said, if (if) 50% of Antarctica melted, sea levels would rise 20 feet. Then he showed how ice has been melting in Greenland over the past few years. Once again, he said if 50% of Greenland melted, sea level would rise 20 feet.

    I don't think stating a worse case scenario is being dishonest.


    Gore claims if you heat a frog slowly, it won't jump out of hot water. (this is a false urban legend)

    Alright, so sue him...


    Gore claims you can easily see the impact of the US Clean Air Act in ice cores. (nobody seems to know where he got this idea from)

    In the movie he says that a scientist friend showed him an ice core, pointed out a specific point to him, and said that that was the year that they passed the Clean Air Act.

    Gore says we have bad cars because even China has higher mileage standards. (Ignores that all but the smallest Chinese cars don't yet meet their own (recently-announced) standard, and ignores that extant Chinese cars tend to be worse in other metrics such as reliability and safety.)

    Right, but that has nothing to do with the fact that China's standards are higher than ours.

    Gore implies a scientific consensus supports the contention that warming is causing more and stronger hurricanes. (it doesn't. Maybe someday it might, but it doesn't now.)

    I don't remember what specific statements he made in the movie. I think he said that hurricanes pick up more force from warm water, and as far as I know, that's a scientific fact, correct me if I'm wrong.

    Gore implies that disease outbreaks and "invasive non-native species" are a warming-related phenomenon. Even Realclimate dings him on that one.


    Global warming could certainly exacerbate invasive species, and mosquitoes and other disease vectors will likely move north if winters get shorter.

    Sierra Club page on diseases.

    Also check out this page.

    The northernmost winter survival of Aedes aegypti is now about 35deg. N latitude, or the latitude of Memphis, Tennessee. This distribution is predicted with global warming to move northward and encompass additional large population centers, the numbers depending on how much warming occurs. In addition, the development of mosquito larvae is faster in warm climates than cold ones, and thus with global warming, the mosquito will become a transmitting adult earlier in the season.

    The extrinsic incubation period of dengue and yellow fever viruses also is dependent on temperature. Within a wide range of temperature, the warmer the ambient temperature, the shorter the incubation period from the time the mosquito imbibes the infective blood until the mosquito is able to transmit by bite.

    I don't want to misrepresent what this paper is saying - the author says there is no proof that global warming will increase disease. But it is true that it can make it easier for diseases to spread.

     

  • At June 21, 2006 8:12 PM, Blogger coby said…

    Future Geek's comment reminded me that I forgot to address the clean air act in ice cores claim. I think a dishonest pundit clarified the issue quite well by misquoting Al Gore as saying "you can literally see ...". Surely it is acceptable to say that in the ice cores one can see CO2 levels rising and falling on 100Kyr cycles, it is an expression. Why shouldn't we assume that this is how Al Gore was speaking about the clean air act?

    I am not arguing the point about invasive species being misrepresented or not, but thought I would point out one example quite reasonably associated with GW, and that is the severe outbreak of pine beetle in BC due to successive mild winters. See here.

     

  • At June 22, 2006 1:34 AM, Blogger Heiko said…

    There are naturally many places with quite mild winters, and it isn't just the pine beetle benefitting.

    Futuregeek over on his blog made an effort to link biodiversity and disease. Rereading some of the stuff I wrote about Jared Diamond's article on agriculture (see my blog) made me notice the connection between "swamps" (today known as wetlands containing precious biodiversity) and public health.

    There we've got good evidence that reduced biodiversity is actually linked to better rather than worse health, and funnily enough it is the kind of evidence brought for claiming that warmer weather is bad for health.

    Biodiversity loss is virtually exclusively argued on the basis of habitat loss, and in particular on the loss of tropical forest (I think 90% tropical forest loss = 50% species loss).

    Climate change doesn't just widen the range of mosqitoes and pine beetles. These are just representative for most insects. Species of butterfly for example will also benefit from mild winters.

     

  • At June 22, 2006 2:00 AM, Blogger Glen said…

    I wasn't dissing the whole film as dishonest, merely noting that there are some dishonest moments within it which detracted from the overall effect. Some sensationalism.

    I second the recommendation of Ronald Bailey's review.

    Enough of the science is on Gore's side that he didn't need to exaggerate. That he did anyway points to a combination of carelessness and the limits of the medium.

    The carelessness comes from the fact that Gore is sure he's right and is used to a sympathetic audience. He doesn't generally need to impress strong skeptics, so the facts being presented aren't as highly vetted for accuracy as they could be.

    As for the limits of the medium: (1) explaining all the caveats and properly sourcing all evidence would make the movie boring. (2) real and/or simulated disaster footage makes for compelling video that tends to lead viewers to leap to predictable conclusions regardless of what the voice-over says.

    There's a tension between being strictly accurate and being entertaining to a large audience.

    More on hurricanes: Gore presents many anecdotes to the effect that hurricanes have been getting worse and more numerous, strangely failing to mention that those who study hurricanes don't think warming is causing an overall increase in either frequency or intensity. He's cherry-picking. Gore backed this up with a bar chart demonstrating the cost of hurricanes has been consistently increasing every year. Falsely implying the hurricanes themselves are getting worse. (as opposed to more houses being built, the cost of land rising, more people moving into the affected regions, more insurance policies being written...)

    Incidentally, you might want to refrain from comments like "I expect the film says X" until after you've actually seen it. :-) (Is it not yet available near you?)

     

  • At June 22, 2006 6:11 AM, Blogger Will said…

    Heiko,

    Warmer winters will affect a healthy ecosystem differently than an unhealthy one. In America, we have a lot of not so healthy ecosystems.

    As for warming benefitting butterflies as well as pine beetles, pine beetles are beneficial in a healthy ecosystem. They have only been a problem when their population gets out of control. Likewise, an out of control population of a certain butterfly, while it might be pretty to look at, could be just as devastating to a local ecosystem.

     

  • At June 23, 2006 1:37 AM, Blogger Heiko said…

    Health is something rather difficult to define for an ecosystem. I mentioned heaths here in Britain and how those came about through overgrazing. Are heaths more or less healthy than the woodland they replaced? What defines eco-system health?

    pine beetles are beneficial in a healthy ecosystem. They have only been a problem when their population gets out of control.

    This throws up loads of questions, like what makes pine beetle population "get out of control"? Does it happen naturally?

    Anyways, it's an example, the more fundamental question is why would expanded ranges of animals and plants be a net negative? What's the analysis supporting that notion that goes beyond anecdotes?

     

  • At June 23, 2006 6:06 AM, Blogger Will said…

    Are heaths more or less healthy than the woodland they replaced? What defines eco-system health?

    The thing about heaths is that they've been a stable ecosystem for a thousand years. That's why they are considered ecologically important to Britain.

    Natural environments can adapt to changning conditions, as the heaths show - but it takes generations.

    This throws up loads of questions, like what makes pine beetle population "get out of control"? Does it happen naturally?

    Acres and acres of pine trees, planted by the logging industry, provide habitat. Warmer winters allow faster maturation and longer breeding periods. Maybe other factors as well, but those are the two major factors that led to the pine beetle explosion.

    Anyways, it's an example, the more fundamental question is why would expanded ranges of animals and plants be a net negative?

    I think that has to do with a lot of factors. If we take warmer winters as a given b/c of global warming, what other factors are we dealing with? Land use changes: logging, habitat fragmentation as the suburbs move further out from city cores and new roads are built, wetlands drying up, drought/excess rain.

    Ecosystem changes: predator species going extinct, prey species going extinct, trees that provide food and habitat not moving north fast enough...

    What if a species moves into an evironment that has some new factor that is intensely favorable? It's population could explode, throwing the local ecosystem out of balance.

    Given the environmental trends over the last 150 years, plus the fact that we are already experiencing a massive extinction, I think it's a safe bet that there will be problems from some species expanding their range.

     

  • At June 23, 2006 8:09 AM, Blogger Heiko said…

    I think you are right that monoculture and warming are both to blame. And that isn't restricted to trees. The reason we've got monocultures is that these systems are particularly productive in yielding the products we want (timber, grain), with minimal effort (easier to cut trees that are all the same size etc..). And the way farmers have reacted to the challenge is by crop rotation, spraying of pesticides and development of more pest resistant plants.

    What if a species moves into an evironment that has some new factor that is intensely favorable? It's population could explode, throwing the local ecosystem out of balance.

    And indeed it'll take a while before it'll find a new, different balance.

    I see a distinction between economically important and esthetically/morally important. I am all for protecting deer or prairies in ANWR, largely for esthetic reasons.

    The economic importance of biodiversity, in so far as it is actually threatened, I think tends to get wildly exagerated. Ecosystmes that are extremely biodiverse are also ones that are hardly utilised for economic purposes. We don't get our food from the wilderness, but largely from fields.

     

  • At June 24, 2006 6:27 AM, Blogger Will said…

    It's hard to draw a line between 'esthetic' biodiversity and 'economic' biodiversity. I think you are right that there is a difference, but it is a spectrum rather than a dichotomy.

    With the pine beetles, timber companies lose money. The pine plantations that are destroyed are a paycheck for a specific year, and if the loggers want to make money in that year, they are going to have to find new land to log.

    Pine beetles also create good conditions for fires.

    In the Phillipines, illegal logging and heavy rain was blamed for a landslide that killed 1800 people.

    A combination of agricultural use and drought has dried Lake Chad, causing famine in the surrounding countries - Sudan and Nigeria. Part of the Aral sea has also dried up from overuse for agriculture.

    In Peru, farmers are having trouble keeping healthy crops. A quote from a NYT editorial, Thomas Friedman:

    "Nearby, in the Sacred Valley of the Incas, Jose Ignacio Lambarri, who owns a 60-acre farm, is also feeling the heat. He grows giant white corn, with kernels that used to be as big as a quarter.

    This corn, which is exported to Spain and Japan, grows in this valley because of a unique combination of water, temperature, soil and sun. But four years ago, Mr. Lambarri told me, he started to notice something: “The water level is going down, and the temperature is going up.”

    As a result, the giant corn kernels are not growing quite as large as they used to, new pests have started appearing, and there is no longer enough water to plant the terraces in the valley that date from Incan times.

    He also noticed that the snow line he had grown up looking at for 44 years was starting to recede, which was making relations with his fellow farmers more difficult. Every year they decide by committee how to divide up the water."

     

  • At November 13, 2006 10:44 AM, Anonymous Anonymous said…

    YOUR AMERICAN PEOPLE HAVE TO AWAKE !

    In living in brazil and I can understand very well the message in this film ?

    WAKE !

     

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