The past few weeks and years have seen a bushel of papers finding that the natural world, in particular perhaps the ocean, is getting fed up with absorbing our CO2. There are uncertainties and caveats associated with each study, but taken as a whole, they provide convincing evidence that the hypothesized carbon cycle positive feedback has begun.
Of the new carbon released to the atmosphere from fossil fuel combustion and deforestation, some remains in the atmosphere, while some is taken up into the land biosphere (in places other than those which are being cut) and into the ocean. The natural uptake has been taking up more than half of the carbon emission. If changing climate were to cause the natural world to slow down its carbon uptake, or even begin to release carbon, that would exacerbate the climate forcing from fossil fuels: a positive feedback.
The ocean has a tendency to take up more carbon as the CO2 concentration in the air rises, because of Henry’s Law, which states that in equilibrium, more in the air means more dissolved in the water. Stratification of the waters in the ocean, due to warming at the surface for example, tends to oppose CO2 invasion, by slowing the rate of replenishing surface waters by deep waters which haven’t taken up fossil fuel CO2 yet.
The Southern Ocean is an important avenue of carbon invasion into the ocean, because the deep ocean outcrops here. Le Quere et al. [2007] diagnosed the uptake of CO2 into the Southern Ocean using atmospheric CO2 concentration data from a dozen or so sites in the Southern hemisphere. They find that the Southern Ocean has begun to release carbon since about 1990, in contrast to the model predictions that Southern Ocean carbon uptake should be increasing because of the Henry’s Law thing. We have to keep in mind that it is a tricky business to invert the atmospheric CO2 concentration to get sources and sinks. The history of this type of study tells us to wait for independent replication before taking this result to the bank.
Le Quere et al propose that the sluggish Southern Ocean CO2 uptake could be due to a windier Southern Ocean. Here the literature gets complicated. The deep ocean contains high concentrations of CO2, the product of organic carbon degradation (think exhaling fish). The effect of the winds is to open a ventilation channel between the atmosphere and the deep ocean. Stratification, especially some decades from now, would tend to shut down this ventilation channel. The ventilation channel could let the deep ocean carbon out, or it could let atmospheric carbon in, especially in a few decades as the CO2 concentration gets ever higher (Henry’s Law again). I guess it’s fair to say that models are not decisive in their assessment about which of these two factors should be dominating at present. The atmospheric inversion method, once it passes the test of independent replication, would trump model predictions of what ought to be happening, in my book.
A decrease in ocean uptake is more clearly documented in the North Atlantic by Schuster and Watson [2007]. They show surface ocean CO2 measurements from ships of opportunity from the period 1994-1995, and from 2002-2005. Their surface ocean chemistry data is expressed in terms of partial pressure of CO2 that would be in equilibrium with the water. If the pCO2 of the air is higher than the calculated pCO2 of the water for example, then CO2 will be dissolving into the water.
The pCO2 of the air rose by about 15 microatmospheres in that decade. The strongest Henry’s Law scenario would be for the ocean pCO2 to remain constant through that time, so that the air/sea difference would increase by the 15 microatmospheres of the atmospheric rise. Instead what happened is that the pCO2 of the water rose twice as fast as the atmosphere did, by about 30 microatmospheres. The air-sea difference in pCO2 collapsed to zero in the high latitudes, meaning no CO2 uptake at all in a place where the CO2 uptake might be expected to be strongest.
One factor that might be changing the pressure of CO2 coming from the sea surface might be the warming surface waters, because CO2 becomes less soluble as the temperature rises. But that ain’t it, as it turns out. The surface ocean is warming in their data, except for the two most tropical regions, but the amount of warming can only explain a small fraction of the CO2 pressure change. The culprit is not in hand exactly, but is described as some change in ocean circulation, caused maybe by stratification or by the North Atlantic Oscillation, bringing a different crop of water to the surface. At any event, the decrease in ocean uptake in the North Atlantic is convincing. It’s real, all right.
Canadell et al [2007] claim to see the recent sluggishness of natural CO2 uptake in the rate of atmospheric CO2 rise relative to the total rate of CO2 release (from fossil fuels plus land use changes). They construct records of the atmospheric fraction of the total carbon release, and find that it has increased from 0.4 back in about 1960, to 0.45 today. Carbon cycle models (13 of them, from the SRES A2 scenario) also predict that the atmospheric fraction should increase, but not yet. For the time period from 1960 to 2000, the models predict that we would find the opposite of what is observed: a slight decrease in the atmospheric fraction, driven by increasing carbon uptake into the natural world. Positive feedbacks in the real-world carbon cycle seem to be kicking in faster than anticipated, Canadell et al conclude.
There is no real new information in the Canadell et al [2007] analysis on whether the sinking sink is in the ocean or on land. They use an ocean model to do this bookkeeping, but we have just seen how hard it is to model or even understand some of the observed changes in ocean uptake. In addition to the changing ocean sink, drought and heat wave conditions may change the uptake of carbon on land. The infamously hot summer of 2003 in Europe for example cut the rate of photosynthesis by 50%, dumping as much carbon into the air as had been taken up by that same area for the four previous years [Ciais et al., 2005].
The warming at the end of the last ice age was prompted by changes in Earth’s orbit around the sun, but it was greatly amplified by the rising CO2 concentration in the atmosphere. The orbits pushed on ice sheets, which pushed on climate. The climate changes triggered a strong positive carbon cycle feedback which is, yes, still poorly understood.
Now industrial activity is pushing on atmospheric CO2 directly. The question is when and how strongly the carbon cycle will push back.
—–
Canadell, J.G., C.L. Quere, M.R. Raupach, C.B. Field, E.T. Buitehuis, P. Ciais, T.J. Conway, N.P. Gillett, R.A. Houghton, and G. Marland, Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks, Proc. Natl. Acad. Sci. USA, doi 10.1073, 2007.
Ciais, P., M. Reichstein, N. Viovy, A. Granier, J. Ogee, V. Allard, M. Aubinet, N. Buchmann, C. Bernhofer, A. Carrara, F. Chevallier, N. De Noblet, A.D. Friend, P. Friedlingstein, T. Grunwald, B. Heinesch, P. Keronen, A. Knohl, G. Krinner, D. Loustau, G. Manca, G. Matteucci, F. Miglietta, J.M. Ourcival, D. Papale, K. Pilegaard, S. Rambal, G. Seufert, J.F. Soussana, M.J. Sanz, E.D. Schulze, T. Vesala, and R. Valentini, Europe-wide reduction in primary productivity caused by the heat and drought in 2003, Nature, 437 (7058), 529-533, 2005.
Le Quere, C., C. Rodenbeck, E.T. Buitenhuis, T.J. Conway, R. Langenfelds, A. Gomez, C. Labuschagne, M. Ramonet, T. Nakazawa, N. Metzl, N. Gillett, and M. Heimann, Saturation of the Southern Ocean CO2 sink due to recent climate change, Science, 316 (5832), 1735-1738, 2007.
Schuster, U., and A.J. Watson, A variable and decreasing sink for atmospheric CO2 in the North Atlantic, J. Geophysical Res., in press, 2007.
AK writes:
[[Assuming 5.8 GHz, and equal sized broadcast antenna and rectenna, both would be 4-5 Kilometers across. (Longer in the east-west dimension if the satellite was at a high angle from zenith.) Transfer efficiency would probably be somewhere between 25% and 50%.]]
Probably I’m missing something simple, but if the antenna and the rectenna are the same size, how do you keep the beam from spreading out? Doesn’t the inverse-square law apply?
Joe Duck Says:
13 November 2007 at 4:52 AM
My take remains as above – the issue is not some absurdity like “AGW is on balance a good thing because we’ll have fewer dead people from the cold”, rather it is “alarmism is bad”. He’s reasonably suggesting that most media accounts, and even some scientists, focus almost exclusively and narrowly on events with a trivial AGW component (European heat wave, Lake Chad, Katrina) while excluding events and circumstances that do not support the idea that AGW peril is imminent and consequences will likely be catastrophic. …
This is the article Lomborg mentions:
“August 2003 was the warmest August on record in the northern hemisphere, but according to the projections of the Intergovernmental Panel on Climate Change (IPCC), even more extreme weather events lie ahead. By the end of the century, the world’s average temperature is projected to increase by 2.5-10.4 degrees Fahrenheit (1.4-5.8 degrees Celsius). As the mercury climbs, more frequent and more severe heat waves are in store. …” – http://www.earth-policy.org/Updates/Update29.htm
AGW caused what heat wave?
Lomborg-errors excerpt:
“… To say that all deaths in excess of 0.54/100,000 are deaths due to ‘cold’, is a misuse of statistics. This misuse becomes even worse when we are said to have the basic death rate only during the 40 days per year, whereas we are said to have excess deaths due to cold not just during winter, but during 287 days per year, that is during 79 % of the year. We get an awful lot of ‘excess deaths’ in that way. Most of these are deaths of elderly people that would have deceased anyway within about half a year.
For each location and each temperature, the average daily mortality is taken from the death statistics. It is then believed – falsely, it seems – that even if climate warms, the death rate at each temperature will remain the same. So, if there will be fewer days with relatively low temperatures then the total mortality will be lower. This belief is not founded on any concrete knowledge….”
An interesting piece under the title “Fuzzy Math” in the current Discover mag, p.19; take with however many grains of salt you deem appropriate.
============
For 115.400 BTU (the amount of energy in one gallon of gasoline), you pay:
Gasoline: $2.86 (actually more, as we all understand, and about to rise another $0.20 according to this morning’s news.)
*Solar – $14.44 (I’m assuming photovoltaic, though they didn’t distinguish.)
Wind – $1.66
Biofuel, B20 – $2.70
*Nuclear – $3.75
*Hydropower – $0.91
Geothermal – $1.69
*Natural Gas – $5.37
Information based on national averages from the Energy Information Administration, the Office of Energy Efficiency and Renewable Energy, and the National Renewable Energy Laboratory, all offshoots of the Dept. of Energy. Power plants measure energy in kilowatt-hours (kWh), and one kWh is equivalent to 3,413 BTU, or about 3% of the energy in one gallon of gasoline.
* – Based on California’s high average price-per-kilowatt hour, according to the California Energy Commission.
=============
Needless to say, it is obvious photovoltaic Solar has a long way to go. At the risk of sounding cavalier, I think with the inevitable factors of innovation and economy of scale will get us there.
Matt, the ivory-billed woodpecker is almost certainly extinct. There’s one *possible* documented sighting in the last 50 years. Even before the $10,000 reward mentioned by jbroon was offered, ornithologists had been looking hard for this species for decades. Not only here, but in Cuba.
And finding nothing.
It’s been years since that one documented possible sighting (an ambiguous out-of-focus video tape, and an audio recording of what might be an ivory-billed, but then again could be a pileated, woodpecker). That neck of the woods has been scoured. Nada. Nothing. This is a large, conspicuous, noisy bird that shouldn’t be that hard to find in breeding season.
As jbroon says, even if a pair or two exist, that’s not a “rebound”.
I do hope the example of the ivory-billed woodpecker makes clear to you the difficulty of documenting the extinction of a species.
Bad analogy. A better analogy is “You have incurable cancer. You have one to eight months to live”.
Because reversing habitat loss is usually expensive.
Most of these aren’t “saved from extinction”, they remain on the endangered list (which means they are at risk of extinction in the very near term).
Also the amount of money spent on these species is huge. That’s why I posed my questions the way I did.
There’s no way we’re going to spend tens or hundreds of millions of dollars on each species at risk of extinction due to human causes. Even here in the US, there’s a huge backlog on the creation of recovery plans for species already on the threatened/endangered lists.
Well, it’s clear that you and lomborg don’t know squat about the subject. E.O. Wilson’s one of the greatest biologists of the last two centuries. I’ll trust his work on this subject over your and lomborg’s handwaving any day of the week.
re 478 (again)
“Discarding the 99% availability standard (actually higher than that) out of hand sounds like the true goal is simply to get us back to nature and near pioneering days (sans all the wood burning, of course!)”
Came across the following regarding this perspective. (Note: this was written a decade before “Collapse”)
=============
There is a popular myth going around. It maintains that there is something particularly corrupt about Western civilization – as if it invented war, exploitation, oppression, and pollution all by itself. Certainly if this were so, the world’s problems might be solved by just returning to “older, better ways.” Many do cling to the fantasy that this or that non-Western culture had some patent or universal happiness.
Alas, if only it were so easy.
In his book “A Forrest Journey: From Mesopotamia to North America,” John Perlin shows how the vast Feryile plains and mountains of Greece, Turkey, and the Middle East were turned into hardscrabble ravines by ancient civilizations. The record of the pillage goes back thousands of years to the earliest known epic, The Tale of Gilgamesh, about a king who cut down primordial cedar forests to take lumber for his city-state of Uruk. Droughts and floods plagued the land soon afterward, but Gilgamesh, nor any of his contemporaries, ever saw the connection.
Summerian civilization went on to seize Oak from Arabia, juniper from Syria, cedar from Anatolia. The rivers of the Near East filled with silt, clogging ports and irrigation canals. Dredging only exposed salty layers below, which eventually ruined whatever soil hadn’t already blown away. The result, over centuries, is a region we know well as a realm of blowing sands and bitter winds, but which was once called the “fertile crescent,” the land of milk and honey.
We don’t need mystical conjectures about “cycles of history” to explain, for instance, the Fall of Rome. Perlin shows how the Roman Empire, the Aegean civilization of ancient Greece, imperial China, and so many other past cultures performed the same feat, ignorantly fouling their own nests, using up the land, poisoning the future for their own children. Ecological historians are at last starting to realize that this is simply the natural consequence whenever a people acquire more physical power than insight.
While it is romantic to imagine that tribal peoples – either ancient or in today’s retreating rainforests – were at harmony with nature, living happy, egalitarian lives, current research shows this to be far from uniformly true, and more often just plain false. Despite a fervent desire to believe otherwise, evidence now reveals that members of nearly every “natural” society have committed depredations on their environment and on each other. The harm they did was limited mostly by low technology and modest numbers.
The same goes for beating up on the human race as a whole. Oh, we have much to atone for, but the case isn’t strengthened by exaggerations that are just plain wrong. Stephen Jay Gould has condemned “…the romantic twaddle the common litany that `man alone kills for sport, but other animals [kill] only for food or in defense.’” Anyone who has watched a common housecat with a mouse – or stallions battling over dominance – knows that humans aren’t so destructive because of anything fundamentally wrong about human nature. It’s our POWER that amplifies the harm we do until it threatens the entire world.
My purpose in saying this isn’t to insult other cultures or species. Rather, I am trying to argue that the problems we face are deep-seated, with a long history. The irony of these myths of the noble tribesman, or noble animal, is that they are most fervently held by pampered Westerners whose well-cushioned culture is the first ever to feel comfortable enough to promote a new tradition of self-criticism. And it is this very habit of criticism – even self-reproach – that makes ours the first human society with a chance to avoid the mistakes of our ancestors.
Indeed, the race between our growing awareness and the momentum of our greed makes the next half-century the greatest dramatic interlude of all time…
…Oh, surely, a good dose of guilt now and then can help motivate us to do better. But I see nothing useful coming out of looking backward for salvation of modeling ourselves after ancient tribes. WE are the generation – here and now – that must pick up a truly daunting burden, to tend and keep a planetary oasis, in all its delicacy and diversity, for future millennia and beyond. Those who claim to find answers to such complex dilemmas in the sagas of olden days only trivialize the awesome magnitude of the task.
David Brin – Afterword to “Earth”
Re: 539
Actually, that’s a square 92 miles on a side: 8464 square miles.
AK says “First, economies of scale will lower the price of launch to orbit by several orders of magnitude.”
And it will do this exactly…how? You are facing the same problem Bill Gates did with Teledesic, and the problem of launch costs was one thing that sunk that project.”
AK goes on to say:
“Second, the entire launch and setup cost doesn’t create a system of power satellites, it creates a system of factories to make power satellites, using power and mass already away from earth. Once that factory system is built, the actual mass of power satellites will be many orders of magnitude greater than what was launched into orbit.”
OK, you’re going to have to help me out here. Where does the mass of the satellites come from if you don’t launch it? Are you proposing to snag meteors as they whiz by? Are you going to set up your infrastructure on the moon? Salvage space junk? Don’t know if you observed this, but space is really pretty empty. Manufacturing in space is also problematic. And again, radiation will limit the lifetime of any factory just as it will your solar arrays. The general rule of economics in space will be: If you make it in space, use it in space, because it doesn’t make sense to overcome the gravity well just to send it back to Earth.
James wrote: “So it’s the first of the type. There are going to be problems building the first one of anything […] The important point is that we know they can be built, and will work, unlike most of the proposed alternatives.”
Since, as you say, the French-designed EPR reactor at Olkiluoto-3 is “the first of the type”, we don’t in fact “know” that it can be built — in anything like the timeframe, at anything like the cost, with anything like the safety standards (which have already been “relaxed” for this reactor) originally proposed. We may find out that it will take much longer, and be a lot more expensive, and have a lot more quality and safety problems than originally expected. And we don’t in fact “know” that it “will work” — as cost-effectively, safely and reliably as originally expected. It may have lots of unexpected problems over time.
What we do in fact “know” about earlier reactor designs is that they typically take longer than expected to build, cost more to construct, and have a lot of problems, including frequent, extended and costly periods of downtime due to safety issues. That’s with “proven” nuclear technology. A big part of the nuclear expansion argument is that the unproven “new generation” of plants will be built faster and cheaper and will be safer. The Olkiluoto-3 reactor suggests that these hopes may not be met.
And we most certainly do know that “most of the proposed alternatives” from large-scale wind turbine “farms” and concentrating solar collectors, to distributed small-scale rooftop photovoltaics, and by far the most important, conservation and efficiency, do work, and work just fine.
re 537 (Dave): “…I imagine the Algerians must have already thought of that (see #530), and must believe they have an answer to it….”
That’t true, but then they are not shipping gigawatts all over Asia and Europe.
Re. #542, Joe Duck, more han half of the deaths from the European heatwave are thought to be atrributable to global warming, and if you consider more than half “trivial”, we use different dictionaries. More importantly, you are missing the point, yet again, that 2003 in isolation isn’t the issue, the issue is that the IPCC projections indicate that by 2100, 2003’s summer will be considered unusually cold, that most European summers will be warmer than 2003 was. The point about 2003 is what it portends rather than the absolute number of people who died that year. This point has been made to you over and over again and it seems to go in one ear and out the other, which is why you keep being accused of trolling. Having to make the same points to you over and over again is extremely frustrating, so please stop this troll-like behaviour.
In addition, as has also been pointed out to you over and over again, the figures Lomborg quoted were misleading in several respects, and you have failed to address any of those points. For example, that it is not the absolute number of people who die in summer vs. winter that is the issue, but how many additional deaths annually are expected as the world warms – and far more additional deaths are expected annually as a result of heat than of cold as the world warms (see IPCC).
In the case of Lake Chad and Katrina the AGW contribution is unquantifiable but the concensus is that is is unlikely to be trivial (increases in SSTs undoubtedly do increase mean hurricane intensity, for example); but more importantly, you are again completely missing the point, a point that has been made to you over and over again but which seems to have fallen on deaf ears, that it what they portend for the future that is the issue. The IPCC projections indicate that drying out of major lakes like Chad, and severe droughts in general, will become far more frequent by 2100, and will lead to the displacement of hundreds of millions of people; and similarly that highly destructive extreme weather events like Katrina wil also become much more frequent by 2100 (the number of hurricanes is not expected to increase but they are expected to become far more destructive on average). That’s the issue – as has been pointed out to you over and over again.
Also, when it comes to extreme weather events, as has also been pointed out to you over and over again but this also seems to have fallen on deaf ears, it is not the proportion of the total contribution that is due to AGW that matters, but whether the AGW contribution was sufficient to lead to it being highly destructive. For example, a recent tidal storm surge in the UK didn’t cause any damage at all because it was 22cm lower than had been expected. Had it been only 22cm higher, it would have breached the flood barriers and caused billions of pounds-worth of damage. It is expected that as a result of AGW, tidal storm surges in the UK will become more frequent and more extreme during the coming century; and furthermore, only a 22cm rise in sea level (expected by 2050 or earlier) would mean that a surge like the one we recently experienced would have breached the flood barriers.So a relatively tiny contribution to the total effective storm surge size by AGW would have been enough to make the difference between no damage at all and billions of pounds worth of damage. Similarly with Katrina, a relatively tiny contribution by AGW might have been enough to make the difference between breaching and not breaching the levies.
If you bring up these issues again without addressing the above points meaningfully, then you are a troll.
Re. my previous post, when I wrote:
I meant, of course, to say that the number of additional deaths that are expected annually as a result of heat are expected to greatly outweigh the reduction in deaths resulting from cold. Sorry about that.
Re Matt’s remarkable claim that species driven to the brink of extinction commonly experience a spontaneous population rebound, without changes in the environmental conditions which are driving them extinct:
Consider the following graphs from links I posted upthread. They show recent population data for several marine species. The decay curves exponentially approach zero. The decay rates have different time constants, illustrating the correctness of Wilson’s phrase, “immediate or early extinction” — see the curves for sea otter decline (fast) and fur seal decline (slower) in the first graph.
Sequential collapse of marine mammals in the North Pacific Ocean and southern Bering Sea [1]
N. Carolina great shark population collapse [2]
Community Changes on the Southern Grand Bank [3]
Matt proposes that in the absence of a change in the environmental factor driving these species to extinction (overexploitation), these populations will rebound. I disagree and propose that these species, and indeed the entire ecosystems they once comprised, will be extinct forever.
On E.O. Wilson’s most recent tour, The Creation: An Appeal to Save Life on Earth, he said it’s estimated to cost about $30 billion to put the most critical wildlife habitats under protection. Is it “alarmist” to say this is not too much to spend to save the world’s biological inheritance from extinction?
—
[1] Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?
[2] Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean
[3] Decline in Biomass
Re #541: [#511. James asks why nuclear power plants need to be decomissioned. It is a question of sea level rise risk.]
No, that didn’t even enter into my question. I was asking why nuclear reactors in general need to be decomissioned, rather than rebuilt and/or upgraded. The question applies just as much to a reactor in Colorado as to one in Florida.
Maybe there are good reasons for decomissioning, but I would point out that there are also going to be costs for decomissioning other forms of generation. What, for instance, do you do with a hydroelectric dam when the resevoir behind it silts up? How about if the concrete weakens with age, or erosion makes it unstable?
As to the sea level rise problem with nuclear reactors, I’d think there’d be better alternatives than decommissioning, like building a dike. The Dutch can build dikes along their whole coastline, so I don’t see protecting a bunch of sites of a few hundred acres as an insurmountable challenge.
Re. 560, Rod B:
They’re planning to ship it all over Europe, according to the article AK linked to.
Re. Edward Mazria, #547:
It’s clearly a disinformation article. The first sentence reads:
First piece of disinformation. It’s nothing to do with the media foisting anything on anyone, it’s the measured sea levels that are rising. The measured global mean sea level trends are shown here.
Sea levels are not the same throughout the world and do not rise uniformly throughout the world. They are falling in some places and rising in others but the average rate of global rise during the 20th century was 0.7mm per year. According the the IPCC AR4 report, this has already started to accelerate.
All sorts of factors affect local sea levels, from winds and currents piling up water locally, to regional salinity levels, to tectonic motion.
To extrapolate from one small region where the sea level is apparently falling (if it really is, I haven’t checked, but you can look New Jersey up on the NOAA website if you want to) as “proof” the sea levels are falling everywhere is as cynically dishonest as the websites that regularly extrapolate from places that are unusually cold as “proof” that global warming isn’t happening.
And to pretend that the sea level measurements by thousands of climate scientists and oceanographers are a “media scare” is equally cynical and dishonest.
James, see the engineering literature on nuclear power.
Short answer: neutron embrittlement
Slightly longer answer: the environment inside a fission reactor changes all the materials for the worse and in ways not completely predictable. Taking them apart is how we figure out how much longer each piece might have been able to function before failing.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXN-4N7S5B2-1&_user=10&_coverDate=08%2F01%2F2007&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=2f97f30b84b26e6ce2525e6bb81b50c4
—–excerpt—-
12 March 2007.
Abstract
The management of materials in power reactor systems has become a critically important activity in assuring the safe, reliable and economical operation of these facilities. Over the years, the commercial nuclear power reactor industry has faced numerous ‘surprises’ and unexpected occurrences in materials. Mitigation strategies have sometimes solved one problem at the expense of creating another. Other problems have been solved successfully and have motivated the development of techniques to foresee problems before they occur. This paper focuses on three aspects of fission reactor experience that may benefit future fusion systems.
——-
564 what do you propose the nuclear reactor islanding dikes should be made of and how high do you propose they should be? 5 metres, 10 metres, 20 metres, 60 metres, 90 metres?
Also, re. Edward Mazria, #547, the article you linked to also states:
This is also an astonishing piece of disinformation. Sea ice doesn’t markedly increase the sea level when it melts, although it does raise them slightly due to the fresh water trapped in the ice being less dense than the sea water it displaces; but land ice clearly does raise sea levels when it melts. This is really basic science and the writer of the article is clearly trying to hoodwink his readers. The Greenland ice cap is melting rapidly, for instance, and the ice from the Greenland glaciers is going into the sea. How can it go into the sea without raising sea levels? Obviously it can’t.
Re: 558
As I understand it, the primary cause was the loss of market. I didn’t pay much attention at the time, I thought (and still do) that broadcast or beamed bandwidth will never be able to compete with fiber except in specialty markets. However, a quick search found an item that said it “will take 175 rockets to put Bill’s star fleet into orbit.” This is hardly enough to generate the kind of economies of scale I’m talking about, although there are rumors that “[t]his caused several groups to start work on new launch vehicles.” I’m talking about launching many thousands of tons of start-up mass in a committed project (presumably funded by a government/private consortium).
[emphasis mine]
In the same post you quoted from, I said:
As originally presented in the 1975 conference the plan was to gather mass from the moon and shoot it into orbit using a linear induction motor (LIM) where it would be collected and converted by factories into solar panels, antenna elements, etc. (To the best of my recollection. My notes vanished decades ago.)
There have been a variety of alternative proposals since, I’m pretty much assuming that the habitations and factories will be on/under the lunar surface where there will be plenty of available mass to shield from radiation and small flying objects. Finished parts will be launched to escape velocity using a LIM and will unfurl some solar power panels, after which they will use MHD or ion drive at very low acceleration to steer themselves into place in GEO. Lifetime constraints mean a certain factory production capacity will translate into a specific final delivered power (say 15-20 years’ production), however the factory capacity itself can be expanded with minimal additional mass from Earth.
This is hardly the only scenario, and most those involved are enthusiasts, So I can’t point you to one place where all these questions are addressed (I wish), but most of them have been considered for most of the scenarios. Unfortunately most of what you see in a quick search is “preaching to the choir”, which isn’t very good for answering the tough questions.
Re: 551
The inverse square law applies to radiation expanding from an effective point source. A phased array antenna is more like a lens. It is “a group of antennas in which the relative phases of the respective signals feeding the antennas are varied in such a way that the effective radiation pattern of the array is reinforced in a desired direction and suppressed in undesired directions.” Looking at a picture of one, you can see how the elements are in a grid, so their phases can be controlled. An aperture 2pi wavelengths across will create a beam about a radian across. One 20pi wavelengths across, about a 1/10th of a radian, and so on. It actually works like a lens, a 20Km antenna in GEO could transmit into a 1Km rectenna. (At 5.8 GHz.)
“The North American Carbon Budget and Implications for the Global Carbon Cycle” has been released by the NOAA.
From the press release:
http://www.noaanews.noaa.gov/stories2007/20071113_carbon.html
“The report points out a greater than three-to-one imbalance between the fossil fuel sources and the ability of vegetation to absorb carbon. This results in a net release to the atmosphere (over one gigaton of carbon per year in 2003), but there is still some uncertainty in quantifying the North American sink compared to the carbon emission sources. The carbon absorption by vegetation, primarily in the form of forest growth, is expected to decline as maturing forests grow more slowly and take up less carbon dioxide from the atmosphere.
“Report authors find it unclear how rapidly this carbon storage “sink” will decline and whether it might potentially become a source since changes in climate and atmospheric carbon dioxide could affect forest growth differently in different regions. Further warming, for example, could exacerbate drought, increasing carbon release through vegetation dieback and increased fire and insect disturbances.”
…and…
“The extraction of fossil-fuels and other primary energy sources and their conversion to energy products and services, including electricity generation, is the single largest contributor to the North American fossil-fuel source, accounting for approximately 42 percent of North American fossil emissions in 2003.
“Electricity generation is responsible for the largest share of those emissions: approximately 94 percent in the United Sates in 2004, 65 percent in Canada in 2003, and 67 percent in Mexico in 1998. These are the latest years for which data are available.
“More than half of the electricity produced in North America is consumed in buildings, making that single use one of the largest factors in North American emissions. In the United States, 67 percent is used in buildings.
“In 2003, the carbon dioxide emissions resulting from energy consumed in United States buildings alone were greater than total carbon dioxide emissions of any country in the world except China. Energy use in buildings in the United States and Canada, including the use of natural gas, wood, and other fuels as well as electricity, has increased by 30 percent since 1990, corresponding to an annual growth rate of 2.1 percent.
“In the United States, the major drivers of energy consumption in the buildings sector are growth in commercial floor space and increase in the size of the average home. Carbon emissions from buildings are expected to grow with population and income.
“The report also characterizes in detail the uncertainty associated with these findings. Variability in physical processes, measurement error, and sampling error all contribute to uncertainty in quantifying elements of the North American carbon budget.”
Abstract:
http://www.climatescience.gov/Library/sap/sap2-2/final-report/sap2-2-final-es.pdf
webpage with links to the entire rport:
http://www.climatescience.gov/Library/sap/sap2-2/final-report/default.htm
AK (#570): As I recall it from the Gerald O’Neill book, the idea was to place electromagnetic catapults, “mass drivers” — i.e., what you call linear induction motors — on the lunar surface, that shoot “bricks” pressed from lunar material in a bucket brigade off the lunar surface, to be collected at the Earth-Moon system’s fifth Lagrange point. There the production facility will be set up… planetary surfaces are really bad, bad places for doing more than is absolutely necessary ;-)
The L5 facility would have all the advantages of the powersats themselves, like constant solar energy and microgravity. Actually the O’Neill idea was to build free-floating space cities for human habitation, with powersats as a side product. Those could then be gently lowered into their geostationary orbit, using ionic drives — plenty of electrical power for those.
Radiation will not be a problem even outside the Earth magnetosphere: lunar dust makes a very nice shield even against heavy primaries from the Sun.
Tough questions? What tough questions? :-)
Re 550
The only thing missing is a major commitment. Current LOX/LH2 technology is mature and ready to be converted to mass production. The actual number of personnel needed in space for the project is probably only a few hundred. If the majority of mass is shipped in multiple units, a certain amount of loss can be allowed for. The same goes for assembly problems in orbit: as long as the overall loss is kept below a few %, it won’t be a problem. This reduces the cost, since everything (in this part of the launch system) can be manufactured to looser tolerances. (It would, of course, be necessary to assure that systems for use by humans weren’t contaminated by low-tolerance manufacture.)
Actually, it could be up and running by 2025 if it were important enough. However, 2090 is probably a better time frame.
The important thing is to start now. Like most such projects, this one will have a long exponential front-end.
“Who’s ‘we’ paleface?” Most of that desert has inhabitants who consider it their territory. Are “we” going to take their solar energy the way “they” took their oil?
Even if the solar power is left in the hands of “inhabitants” to sell on the open market, most areas in the world, especially desert areas, have a tribal culture with all sorts of internal feuds that could target the income streams of enemies. Not to mention transmission lines, and the areas they cross.
And what about the damage to the environment, real and perceived? There are already conflicts rising between environmentalists and people who want to mitigate CO2. There are people who use violence attempting to stop all use of laboratory animals in disease research. How sure can we be that similar groups won’t arise to protect the desert ecosystems from “exploitation”?
And don’t forget local politicians who’ll try to hold projects hostage for their own agendas, especially once they’re complete and people are depending on them.
I’m all for “build[ing] some big CSP plants in the hot deserts“, but given the socio-political risks, we should also pursue space based power as hard as possible.
In the long run, deserts will be more valuable as pristine ecosystems once power is available from orbit, why not preserve as many as possible by getting space-based power under way now?
Re: 573 Martin Vermeer
A stub of an industrial base would still have to be set up on the moon, to “mine” moondust and run the process to shoot to orbit. Most of this would be robotic, but IMO you’d need some people nearby (within very sub-second response time) to supervise. L5’s 2-second response time probably wouldn’t cut it. (Besides, if it did, you could run it from earth.) I don’t recall L5 being part of the scenario that didn’t include habitats, but I could be remembering wrong.
More importantly, things have changed since High Frontier was written. The assumption was that the phased array antennas would need to be precision objects many kilometers across. With today’s technology, you could make each centimeter-scale element “smart” so it could track its relative position and manage its own phasing. All you need is a big net stretched out, with an element at each node, you don’t need precise positioning. (That also makes the whole thing much cheaper.)
In fact, you don’t even need that. A few thousand 100-meter antennas that blanket the aperture area (and know where one another are) is all you need.
The “hard questions” are the ones for people not already familiar with the idea. We should probably take our technical discussion elsewhere and reserve comment here for issues related to the part SPS’s can play in solving the climate problems.
Dave Rado:
First, don’t mischaracterize my points. I said the AGW component was trivial. You clearly slipped in GW to strengthen your questionable points.
It is generally important to make a distinction between GW and AGW and it is imperative to separate out regional climate issues which trump the other factors in almost all cases. e.g. Landsea’s work suggests a few MPH extra for Katrina due to increased ocean temps. Given that almost all the destruction was the indirect result of defective levee system, it’s simply not rational to conclude that Katrina is a good example for an AGW analysis. Yet this is exactly what is often suggested. You, not I, dodge these obvious flaws in the alarmist arguments because Katrina and Chad are thrown out to inspire activism rather than enlightenment. Lake Chad was an almost entirely regional climate issue which combined with irrigation issues to dry that lake. Some research does suggest AGW inspired desertification will slow replenishment. As with most AGW perils however, the future effects are speculative at best and highly alarmist at worst.
Believing in a very likely AGW component to GW is responsible science, believing AGW is likely to lead to catastrophic climate change is an irrational interpretation of the excellent IPCC data, which is why IPCC does not use the catastrophic language and “certainty” claims so common here.
You seem to suggest that 2100 or 2050 are the issue here. That is true (current situation is not bad), which is why we need *modest mitigation*, less alarmism, and more refinements to modelling and technologies. Why do moderate mitigation before we squander billions on questionable massive mitigations? If the answers aren’t obvious to you there’s nothing I can say to help.
Of course the key issue is the future *because the present circumstances are OK with respect to Climate*.
What points have I not addressed? You just don’t like my interpretations, which is fine, but hardly cause to berate me constantly and unjustifiably.
I’ll examine your claim that 50% of the Europe heat deaths were the result of AGW. On the surface this seems really questionable to me.
Also Dave – it is hard enough to participate here when people are reasonably expressing their interpretations of the facts at hand, which generally differ from my interpretation. The attacks on people here who express alternative interpretations are unwarranted and dimish everybody’s ability to attain enlightenment. There is mo need here to call me a “troll” because I do not accept your questionable and irratic interpretations of the evidence at hand.
AK, I work with satellites. What is being proposed here borders on science fiction. The reality is that NASA will struggle to establish a permanent moon base by 2020 to 2025–and that is just a base, not a mining and manufacturing conglomerate on the moon. You will not mass on that deal. It is a mistake to underestimate the difficulty of doing anything in space. I recommend watching the space station astronauts in NASA TV sometime–they have a full-time job just staying alive.
Joe Duck,
Great point except that there is no difference between GW and AGW in the present context- something you couldn’t possibly not know having been posting here daily for weeks short of your being a study in dumb in the headness. I can’t conclude you are a troll with IPCC caliber certainty, but it’s getting close. Let’s see the recent evidence: you made a big stink to Nick Gotts about some point that you ‘had to challenge’ and when he drew your attention to a compelling argument from John Quiggin’s on the subject that engaged in more than name dropping you ignored it. Apparently it was no longer imperative that you correct whatever it was you thought you corrected in the first place. You’ve likewise ignored a number of my posts on the subject of your great economics consensus or inferred some question or point that I wasn’t remotely making so you could dismiss them with nonsense and go on trolling. Frankly, if you’re serious about wanting to engage people here, you ought to attempt to redress these crimes against the blog. When you don’t bother, well that’ll be just one more nail for the coffin.
re J.S. (556)
Very good! I agree. One caution (not a disagreement) re: “…it is this very habit of criticism – even self-reproach – that makes ours the first human society with a chance to avoid the mistakes of our ancestors.” It is a very fine line between that and the corresponding charge that man is the only animal who exuberantly plans and supports his own downfall and demise.
Re. Joe Duck, #576:
More han half of the deaths from the European heatwave are thought to be atrributable to AGW, so it’s you who is misrepresenting my point rather than the other way around. I did not mischaracterise your point, I just forgot to write “anthropogenic”. Given that there is no evidence that I have ever seen that any of the warming experienced since 1975 is not anthropogenic, I don’t see why you think missing out the word “anthropogenic” is important. What element of the last thirty years’ warming do you consider not to be anthropogenic? What non-anthropogenic forcing agent do you consider responsible for it and on what evidential basis? See here for instance.
You have also misrepresented my reasons (and the reasons of several other people) for accusing you of trolling. No-one here accuses people of trolling simply because we disagree with them. I explained the reasons very clearly, and in previous posts I have spent a great deal of time documenting the evidence to back the accusation up. Your behaviour is troll-like because you make a point, someone points out what they believe to be a flaw in your point; you then ignore their post and make the same point again. Someone else points out the flaw. So you ignore their post as well and make the same point again. And again. So you waste hours of our time, as we end up feeling as if we’re talking to a brick wall.
For this reason, I won’t respond to the other points you made in your post, because based on your track record, you’ll simply ognore what I write and I don’t have any more time to waste on this.
Ray, an atom bomb certainly seemed like science fiction in 1935. I recall a story (maybe apocryphal) about the editor of a science fiction magazine during WWII who got a visit from the FBI over a story about an atom bomb. Of course, that science fiction turned into fact.
I’ll stand by my statement, although I’m not anything like an expert in current satellite technology: We could do it by 2025 if we wanted to badly enough. I suspect (from what I’ve heard) that the first thing that would have to happen is that somebody would go through NASA with fire and the sword (so to speak). We would also have to take a more cavalier attitude toward risk.
But I also agree, that “NASA will struggle to establish a permanent moon base by 2020 to 2025“. Maybe not even that, depending on the interest and pressure.
I’ll take your advice and watch some NASA TV, but can you tell me: How much of the difficulty is from lack of gravity, and how much from vacuum?
#546 Barton Paul Levenson:Not quite. Nuclear plants use large quantities of cement, and machines used in mining uranium are generally fossil-fuel powered.
You know how massive current wind turbines are don’t you? The mast for this (1) 750 KW is 55 tons. The blades are 4 tons each. It is 180 feet tall. We need about 1.8M of these things to minimally meet our needs.
If the concrete base to hold this up this structure is 5X the mast + blade height, and if it indeed (2) takes 400,000 yds3 of concrete for one nuke plant, and if we need 400 nuke plants to run the US…
Surprise, surprise…building out all nuclear would take 1/3 as much of concrete as building out all wind power.
If the masts are steel, building out the US for wind would take 2700 times the amount of steel that it took to build Taipei 101.
(1)http://www.mpsutility.com/TurbineStats.htm
(2)http://www.nei.org/keyissues/reliableandaffordableenergy/factsheets/nuclearpowerplantcontributions/
Re #546: [Nuclear plants use large quantities of cement, and machines used in mining uranium are generally fossil-fuel powered.]
Coal-fired plants likewise use large quantities of cement, and must mine a far larger amount of material per unit of energy generated. In any case, a moment’s thought will show that the amount of CO2 generated in building a coal-fired plant and mining the fuel must be much, much smaller than what is produced in generation.
[There would be technical problems switching them to electric; those machines need to generate a lot of energy fast.]
In fact, much mining equipment is already electrically powered. (I used to work for a utility that frequently needed to do reliability/stability studies due to extending power lines to new mines.)
Re #567: […the environment inside a fission reactor changes all the materials for the worse and in ways not completely predictable. Taking them apart is how we figure out how much longer each piece might have been able to function before failing.]
True. And once you learn how long each piece can function, you make sure to replace it before that time expires. Just as with the engine of car, I can replace spark plugs, timing belts, piston rings, & other parts when needed, instead of “decommissioning” the car when one part reaches its useful service life.
And $568: [what do you propose the nuclear reactor islanding dikes should be made of…]
You’re asking me? I’m a software engineer: find some Dutch engineers with experience in dike building, and ask them. Or think of other alternatives, such as encasing the reactor in a large submarine :-) The point is that you’ve got an expensive piece of equipment sitting there: why assume that all you can do is take it apart and haul it off to an expensive junk heap?
Yep. Short of some country being willing to throw money and people wholesale into space, and accept levels of loss far greater than anything NASA has actually experienced, it won’t happen.
Note that NASA has accepted losses far greater than anticipated.
Two shuttles lost.
And the low Earth orbit is so full of garbage now that the amount of debris is going to keep increasing from further collisions — known for sure, happening — so the risk will be going up dramatically for a while yet.
What would it take? Oh, maybe a serious catch-and-release effort to tag and tie steering motors onto a handful of asteroids as they got barely within reach (by the USA and Russia, for example, a maximum reach effort) followed by a lapse of time while that mass was steered slowly into useful orbits — followed by a wholesale throwing of people and equipment into space to work with the material available, taking great losses to accomplish building a new world.
Could happen. But yes, it’s science fiction.
And a huge flurry of dirty launches isn’t going to do the climate any good either, unless we really decide dumping a whole lot of rubber cement and aluminum oxide into the upper atmosphere is a good plan to put off some incoming sunlight.
Heck, I’d put money into a long-horizon catch-and-release, even knowing it’d not pay off or fail til long after my lifetime. Get a passel of small ion engines and a big net and some programmable machinery out there to snag what comes by and begin herding it around the sun a few more times til it can be captured near Earth — why not?
But it’d be one of those gestures, with not much idea who’d benefit from pulling the goodies into closer to Earth so someone later could reach them and make something out of them without such a stretch.
AK @ 574: “Who’s ‘we’ paleface?”
My “we” was of course the human race. Who will actually build the plant, sell the power, and reap the rewards? Whoever owns those tracts of desert. The Algerian government, for a start.
As for tribal groups, I don’t suppose that Chinese government will encounter much opposition from tribal groups when they convert tracts of the Gobi to solar power production. Ditto Arizona, New Mexico, Mexico, Texas, etc. The Namibians are interested in selling solar power to South Africa.
One day, the future government of the Saudi peninsula will sell sunlight from the Empty Quarter.
ON SPS: LH2/LOX is not a launch system! Where’s the launch system? What’s the vehicle? What’s the motor? What’s the launch site?
How are your lunar mines and mass-drivers to be powered? Solar, or nuclear? Where’s the lunar nuke plant? Do we know how to build a nuke plant that will operate correctly in lunar gravity? Do we even know how to build a nuke plant which can survive launch to the lunar surface?
Where are your prototype robot mines? How well do they work in hard vacuum, lunar gravity, and with moon dust?
Etc etc etc. I read High Frontier in the 1970s, and I still believe that if the human race can dodge various bullets then our descendants will live among the stars. But mega-engineering projects are hard, and your mega-engineering project is way harder than mine.
I think 2090 is plausible, but 2025 is not.
Further to AK’s post in #530 about the Algerian project, with its link to this news article, and the comments by Rod B in #533, Barton Paul Levenson in #548, and previously, Ray Ladbury in #528, I emailed Franz Trieb, who was extensively quoted in the news article, asking about these issues, and I got the following detailed response:
This looks very exciting to me, and I don’t understand why it’s getting so little publicity. Seems to me that large scale investment in this type of project would be an ideal use of CDM funds. Am I missing something? (No glib answers please – Franz has provided links to a substantial body of research and I think it deserves considered responses).
The contention that a severe weather event has to have a proven AGW component in order for it to be used as an example of what a severe weather event of the future might look like is lunacy before it gets out of the gate.
He’s essentially arguing that Lake Chad does not look like what the dry lake beds of the future will look like, and that’s preposterous. Dry lake beds sort of look alike. Mountains that have lost their glaciers all sort of look alike. A nude mountain top in the state of Washington is going to look like a nude Kilimanjaro. All severe hurricanes sort of look alike.
And just for the record, Katrina kicked butt in Mississippi. It didn’t just happen in Louisiana.
re 580
“Your behaviour is troll-like because you make a point, someone points out what they believe to be a flaw in your point; you then ignore their post and make the same point again. Someone else points out the flaw. So you ignore their post as well and make the same point again. And again. So you waste hours of our time, as we end up feeling as if we’re talking to a brick wall.”
Very old Creationist “tactic”. Ignore anything that is said in rebuttal you can’t address and then repeat the argument over and over until the other side gives up trying to “discuss” things with you.
Claim “victory”.
re 579
“Very good! I agree. One caution (not a disagreement) re: “…it is this very habit of criticism – even self-reproach – that makes ours the first human society with a chance to avoid the mistakes of our ancestors.” It is a very fine line between that and the corresponding charge that man is the only animal who exuberantly plans and supports his own downfall and demise.”
====================
One needs to be cautious not to loose the context of Brin’s remarks, a context that more or less moots the suggestion you are making.
Loose the “Exuberantly” and even that is a valid observation (though that is NOT what Brin was getting at…it’s more of the same two light bulbs and a transistor radio fallacy you used earlier).
Name any other animal that knowingly plans and implements technological projects on a massive scale that clearly can be shown to have a detrimental effect. That’s the essence of the statement you made, and it is false.
Brin’s warning is very clear: “It’s our POWER that amplifies the harm we do until it threatens the entire world … it is this very habit of criticism – even self-reproach – that makes ours the first human society with a chance to avoid the mistakes of our ancestors.
… the race between our growing awareness and the momentum of our greed makes the next half-century the greatest dramatic interlude of all time …” (Note: this was written in 1989.)
http://www.asimovs.com/_issue_0311/ref2.shtml
“.. 1944, while American scientists in New Mexico were planning the first A-bomb, John W. Campbell of Astounding Science Fiction published a story called “Deadline,” by Cleve Cartmill, which described in great detail how to construct such a bomb.”
— Robert Silverberg
Re: 586
It took me a while to find some modern sources regarding the on-going violence in Algeria (among all the older stuff of the same type):
Africa’s unfolding desert war
Zawahiri threatens North Africa leaders, Abu Laith to support Algeria’s Al-Qaeda
Military Guide to Terrorism: Future Terror Trends
Google it yourself, I got “Results 1 – 100 of about 80,100 for algeria GIA combat islamist. (0.20 seconds)”
Conditions within China are open to question, but it’s doubtful they’ll have power to sell outside their own borders. Mexico is doubtful as well (look at their oil production), as is sub-Saharan Africa. Arabia won’t be selling sunlight to “infidels” for quite a while, if ever. The US looks quiet at the moment, but you’re forgetting the environmentalists, as well as entrenched interests.
I said “Current LOX/LH2 technology is mature and ready to be converted to mass production.” Current systems, such as the Ariane 5 are effectively one-off prototypes. Conversion to mass production remains, starting with prototypes of designs specifically intended for mass production.
Lunar operations to be solar powered, probably using silicon-based PV systems, with whatever energy storage system is most feasible. (IMO either flywheel or capacitor.) Robot factories and mines are already in operation here (very limited robotics, I’ll agree). Some testing of hardware constraints would be needed early (a manned Lunar expedition wouldn’t be needed for moon-dust testing), as for software, I’ve personally seen a two orders of magnitude difference between what can be done by the right people under pressure, and what happens when it’s left to “business as usual”. Remember, software testing wouldn’t need to be done on the moon (except for the final phase), hardware simulators on earth could provide the test bed, once hardware on the Lunar surface had measured the parameters of the effects.
2025 is technically feasible given the right human conditions. Politically, 2090 is probably a better bet, but IMO the same can probably be said about wide-scale solar power.
James, “once you learn”
Maintaining a fission plant for decades is nothing like changing the spark plugs in your lawnmower. Yesterday you didn’t know what the problem was, and today you’re proclaiming it’s trivial. Read a bit.
Re: 587 Dave Rado
You don’t need to keep giving me credit, all I did was play with Google a little.
I haven’t reviewed the links you provided, but it sounds very optimistic, technically. My concern about sandstorms has more to do with lifetime of moving parts than actual wind (except for its ability to drive dust into bearings, etc.) These are perfectly solvable problems (just as space problems are), and certainly not unfamiliar to oil equipment workers in such environments. (Well, not the space problems.) I’m just not sure about the expense for productionalized results.
In an earlier post I reviewed some political problems, both Algerian and US. Dr. Trieb’s comment “Strange thing that this is fairly unknown as those plants are on the grid since the mid eighties of the last century” points up my comment about entrenched interests.
AK, Re: the difficulty of working in space. I would characterize the difficulty of maintaining life in space as being a case of space providing nothing needed to maintain life. All oxygen, water, food, waste disposal… is dependent on regular deliveries from Earth. The crew need to be protected from particulate debris, radiation, and other hazards. In low-Earth Orbit (LEO) atomic oxygen causes chemical weathering of surfaces. In middle Earth orbit (MEO), the radiation environment makes life particularly nasty, brutish and short. Outside the magnetosphere (GEO, interplanetary, including the moon), there is constant exposure to galactic cosmic rays–and you need a few meters of material to shield against them.
Think of the difficlty of supplying an advanced force on the battle field. Now multiply those difficulties by several orders of magnitude and you have an idea of the difficulties of operating in space. Look at the failure of Biosphere II–and they were able to take in air from the outside continually.
As to terrestrial solar farms, we’re a long way from being able to tile the desert with solar arrays, and maintaining these farms in the hostile desert conditions is not a problem that will be easy to solve.
Re #593: [Maintaining a fission plant for decades is nothing like changing the spark plugs in your lawnmower.]
Aside from the fact that my lawnmower doesn’t have spark plugs (it’s electric, of course), how is it different, in principle? You replace what wears out. Seems like modern society has forgotten that, and regards everything as disposable.
[Yesterday you didn’t know what the problem was, and today you’re proclaiming it’s trivial. Read a bit.]
Yesterday (well, the day before now) I asked a rhetorical question. Now I’m saying that the problem can almost certainly be addressed at much less cost than full decomissioning. The point I’m trying to get at here is that opponents of nuclear power invariably pick the worst case scenario, exaggerate that beyond all reason, and compare it to the best case of an alternative technology. Or all too often, assume that the alternatives have no costs or risks at all. That’s neither fair nor realistic, and will lead to less than optimal decisions being made.
Thanks, AK.
-BPL
Joe Duck — All GW is AGW. Here is the reasoning: orbital forcing theory explains the swings between stades (massive ice sheets) and interstadial periods (less ice). It is possible to compute with great accuracy the orbital forcings far into the past and into the future. From this, without anthropogenic influences, the climate should be very slightly cooling from the so-called Holocene Climatic Optimum, about 8,000 years ago, with an attempt at a stade in about another 20,000 years. The remarkable stability of the climate for the past 8,000 years has been attributed by W.F. Ruddiman to anthropogenic influences. His book Plows, Plagues and Petroleum presents this theory (and is a good read). Better understanding of the orbital forcings makes it clear that his case is somewhat over-stated until rather recently.
None the less, with warming occuring in what should be a slowly cooling climate, there must be a cause. It is known to be the additional carbon added anthropogenically to the active carbon cycle (along with other anthropogenic effects of lesser immediate impotance).
More from Franz Trieb. I emailed him again, and wrote:
He replied:
Dave (561) more than half of the deaths from the European heatwave are thought to be atrributable to global warming
http://www.climateprediction.net/science/pubs/nature03089.pdf
Dave I’ve reviewed this paper which is somewhat relevant to the “warming” side of the deaths from AGW discussion and also interesting. However I simply don’t understand how you can pull out the wild conclusion that half the deaths in europe were from AGW. My read is that they concluded that it is very likely that humans (I assume they mean AGW) have doubled the risk that heat waves would cross the temperature threshold they set in the study. Extrapolating that half the deaths from the heatwave are from AGW does not make sense to me but maybe I’m really missing something here. A death extrapolation using only this very limited study would not be possible, but to come to your conclusion wouldn’t you have to assume all the deaths from the heat wave were a result of crossing the threshold value they set for the study – isn’t this an unreasonable assumption? I’ll try to write the authors of the paper since this it the type of study that is often characterized oddly in the media as suggesting things it does not suggest, which seem fairly technical and probabilistic to me rather than “helpful” in terms of policy.
David wrote: “All GW is AGW”. I’ll follow up as this “sounds” odd to me. My impression from IPCC 4 was that it’s likely that most of the observed GW is a product of AGW, but the relationships are simply too complex to make this definitive of a statement about causality. However I’d agree if it’s “very likely” that “all the GW” is from AGW (rather than “most of the GW”), your statement is reasonable.
Majorajam, Dave: It is hardly fair to say I don’t follow up here. You often want to direct the discussion to your interpretation of events rather than a general examination that might challenge your deeply held points of view. I’ve stated my general view instead of going down your garden path – nothing wrong with that and calling “trolling” is a spurious claim to bully people away from the blog. That approach is common here but unfortunate since this is potentially a great watering hole for informed discussions.