Alert readers will have noticed the fewer-than-normal postings over the last couple of weeks. This is related mostly to pressures associated with real work (remember that we do have day jobs). In my case, it is because of the preparations for the next IPCC assessment and the need for our group to have a functioning and reasonably realistic climate model with which to start the new round of simulations. These all need to be up and running very quickly if we are going to make the early 2010 deadlines.
But, to be frank, there has been another reason. When we started this blog, there was a lot of ground to cover – how climate models worked, the difference between short term noise and long term signal, how the carbon cycle worked, connections between climate change and air quality, aerosol effects, the relevance of paleo-climate, the nature of rapid climate change etc. These things were/are fun to talk about and it was/is easy for us to share our enthusiasm for the science and, more importantly, the scientific process.
However, recently there has been more of a sense that the issues being discussed (in the media or online) have a bit of a groundhog day quality to them. The same nonsense, the same logical fallacies, the same confusions – all seem to be endlessly repeated. The same strawmen are being constructed and demolished as if they were part of a make-work scheme for the building industry attached to the stimulus proposal. Indeed, the enthusiastic recycling of talking points long thought to have been dead and buried has been given a huge boost by the publication of a new book by Ian Plimer who seems to have been collecting them for years. Given the number of simply made–up ‘facts’ in that tome, one soon realises that the concept of an objective reality against which one should measure claims and judge arguments is not something that is universally shared. This is troubling – and although there is certainly a role for some to point out the incoherence of such arguments (which in that case Tim Lambert and Ian Enting are doing very well), it isn’t something that requires much in the way of physical understanding or scientific background. (As an aside this is a good video description of the now-classic Dunning and Kruger papers on how the people who are most wrong are the least able to perceive it).
The Onion had a great piece last week that encapsulates the trajectory of these discussions very well. This will of course be familiar to anyone who has followed a comment thread too far into the weeds, and is one of the main reasons why people with actual, constructive things to add to a discourse get discouraged from wading into wikipedia, blogs or the media. One has to hope that there is the possibility of progress before one engages.
However there is still cause to engage – not out of the hope that the people who make idiotic statements can be educated – but because bystanders deserve to know where better information can be found. Still, it can sometimes be hard to find the enthusiasm. A case in point is a 100+ comment thread criticising my recent book in which it was clear that not a single critic had read a word of it (you can find the thread easily enough if you need to – it’s too stupid to link to). Not only had no-one read it, none of the commenters even seemed to think they needed to – most found it easier to imagine what was contained within and criticise that instead. It is vaguely amusing in a somewhat uncomfortable way.
Communicating with people who won’t open the book, read the blog post or watch the program because they already ‘know’ what must be in it, is tough and probably not worth one’s time. But communication in general is worthwhile and finding ways to get even a few people to turn the page and allow themselves to be engaged by what is actually a fantastic human and scientific story, is something worth a lot of our time.
Along those lines, Randy Olson (a scientist-turned-filmmaker-and-author) has a new book coming out called “Don’t Be Such a Scientist: Talking Substance in an Age of Style” which could potentially be a useful addition to that discussion. There is a nice post over at Chris Mooney’s blog here, though read Bob Grumbine’s comments as well. (For those of you unfamiliar the Bob’s name, he was one of the stalwarts of the Usenet sci.environment discussions back in the ‘old’ days, along with Michael Tobis, Eli Rabett and our own William Connolley. He too has his own blog now).
All of this is really just an introduction to these questions: What is it that you feel needs more explaining? What interesting bits of the science would you like to know more about? Is there really anything new under the contrarian sun that needs addressing? Let us know in the comments and we’ll take a look. Thanks.
There’s a point here? I can imagine a few which are ecologically ignorant but I don’t want to put words in your mouth …
I’m just saying it should be knowledge driven. And we have to acknowledge that there have to be trade-offs. But if we don’t knowledge, how do we identify trade-offs and make intelligent decisions?
As an example … sage grouse are a species of concern, probably should be listed. One of the stimulus projects funds a study of wind farm-sage grouse interactions in ne oregon (I only know because some anti-science republican wingnut senator from oklahoma is trying to block it).
One way to look at it is “oh no, if we uncover hazards to existing sage grouse populations, we may be limited as to where we build wind farms, so let’s just claim wind mills are harmless to birds!”
Another way …
What we learn may help guide the siting process AND perhaps more importantly, guide siting of habitat restoration and sage grouse re-introduction projects in the future. Because restoring a healthy population of sage grouse is going to require habitat restoration, typically (AFAIK, a bit of a WAG here) a regime of prescribed burning and reseeding with native grasses (sage grouse when young are dependent on the seeds of a variety of grasses), doing so in a way that promote a variety of structure (open areas, areas with large shrubs, etc, the latter important because older, taller sage and other woody shrubs are required for cover especially during nesting) etc. Not cheap, and more research needed.
If wind farms are truly harmless to sage grouse, well, a wind farm might be a great place for a restoration project. More likely, we get information on how to site both wind energy projects and restoration projects in ways that minimize the negative impact of the first, and maximize the possibility of success of the second.
Totally. The environmental community has been preaching energy conservation for decades, in order to minimize the demand for energy thus the impetus to develop the north slope, oil sands, etc. Now that AGW has been established beyond doubt (and has been for far too long), we’ve got another compelling argument for conservation.
For some reason the argument that conservation generally saves consumers money has never been a winning one … though that seems to be changing, too.
Folks, if you haven’t clicked on Jim Bouldin’s name — please do.
Reading from the people actually working in the field helps a lot.
PeterMartin – “Of course it can well be argued that no simple equation can be truly representative of the real relationship, over all concentrations, but the contrarians have latched on to the logarithmic relationship to produce all kinds of improbable curves. Isn’t it time to make a little more of the linear relationaship at lower concentrations?”
Yes. The relationship must be approximately linear at low concentrations. CO2 optical thickness decreases away from the approx. 15 micron wavelength center of it’s absorption band. That is really a general trend over fluctuations across small wavelength intervals between absorption line centers and gaps between them, but the trend can be traced through the line centers, through the minima between line centers, etc. When there is a high enough concentration, the effect at the tropopause level is saturated at the most opaque wavelengths near the center of the band – meaning that adding more CO2 makes little direct change to net upward longwave radiative flux at those wavelengths at the tropopause level (the troposphere and surface, coupled by convection, tend to warm up and cool off together in response to radiative forcing at the tropopause level, evaluated after stratospheric equilibration but including further stratospheric feedback to the changes below the tropopause – with variations in this pattern over seasons and latitudes, etc.) (Stratospheric equilibration is the temperature response in the stratosphere in the absence of changes below the tropopause – it is generally a cooling effect for increased greenhouse gases because it increases the stratosphere’s opacity to space (it can be seen more from space – it radiates more to space) while blocking more radiation from the surface and warmer lower tropopshere. The effect for ozone is complicated because ozone can recieve radiation from the surface and warm humid airmasses or low level clouds at wavelengths in which, absent clouds, the air in the troposphere (except in low level warm humid air) tends to be somewhat transparent (because of the reduced concentration of ozone relative to the stratosphere); its dominant effect is in aborbing solar radiation.) However, additional CO2 continues to have an effect at other wavelengths. The shape of the CO2 absorption spectrum is such that after some amount of saturation in the center of the band, the intervals of wavelengths of moderate opacity (where the greatest change occurs when more CO2 is added) shift outward from the center of the band as the central high opacity interval widens approximately linearly in proportion to the logarithm of CO2 concentration.
———-
James –
“Humm… Just how thin can a thin-film PV cell be made? Or maybe mirror-surfaced balloons, reflecting on to a central solar thermal generator… Quick, somebody call my patent attorney!”
Solar balloons:
http://abcnews.go.com/Technology/Earth2100/story?id=7736882&page=1
See Annotated Transcripts:
Endnote 33 of Act 11
“Solar cells are expensive, so it makes sense to use them efficiently. One way to do so is to concentrate sunlight onto them. That means a smaller area of cell can be used to convert a given amount of light into electricity. This, though, imposes another cost—that of the mirrors needed to do the concentrating. Traditionally these are large pieces of polished metal, steered by electric motors to keep the sun’s rays focused on the cell. But now Cool Earth Solar of Livermore, California, has come up with what it hopes will be a better, cheaper alternative: balloons.
Anyone who has children will be familiar with aluminised party balloons. Such balloons are made from metal-coated plastic. Cool Earth’s insight was that if you coat only one half of a balloon, leaving the other transparent, the inner surface of the coated half will act as a concave mirror. Put a solar cell at the focus of that mirror and you have an inexpensive solar-energy collector. (Source: “Solar Energy: Party Time!” The Economist, March 5th 2009)”
(But how are these aimed?)
This also reminds me of an ‘experiment’ I did, trying to make a concave mirror by stretching plastic wrap over a bowl and then pressing it in to push some air out.
(PS an alternative could be to use fixed spherical or circular-cylindrical mirrors on the ground, with a moving grid suspended above to track the focal points/lines – spherical aberation limits the amount of concentration, but maybe the economics would be better? Or how costly would it be to use corrective lenses/mirros on the moving grid?).
One time I came up with an idea for using soot in solar cells, and then found out that people were experimenting with camphoric soot.
For thin-film technology – I think the photovoltaic layer is generally a few microns thick. This could be reduced by using plasmons.
Crystal Si has had to be in thicker layers, I think about 300 microns, because the Si layer is manufactured as a stand-alone component before additional layers are added, and thus has had to be mechanically strong enough to withstand the processes. Aside from that, though, it has to be at least … not sure, maybe 100 to 200 microns, in order to absorb most of the photons available, because unlike many other semiconducting materials, it has an indirect band gap – the minimum energy level of the conduction band and the maximum energy level of the valence band do not line up at the same electron wave vector (within solids, an energy band is actually a range of values taken by energy as a continuous function of wave vector (proportional to momentum) within what I believe is called a brillioun zone; electrons travel with group velocity which is somehow related to the gradient of the energy over wave vector space (forgot details), and this averages to zero over all the states within a given band, which is why an electric current requires a band to have at least some occupied and some unoccupied states (holes) – at least that’s my understanding of it). Once excited across the band gap, electrons and holes will tend to settle into the energy levels closest to the fermi level by thermal relaxation (I think) (except in ‘hot carrier’ technology where electrons and holes are removed fast enough so that a significant amount of the otherwise excess energy is used), so for an indirect band gap material, none of the electron-hole pairs can really carry the energy of even the least energetic photon that is easily absorbed; photons of energy closer to the band gap energy can be absorbed but only by processes that are less likely and thus require longer photon path lengths to become significant.
Crystal Si layers could be made thinner using light-trapping, whereby diffuse back reflection, with perhaps scattering at the front interface, utilizes total internal reflection, so that a large fraction of photons that are not absorbed in one round trip are likely to be given another chance.
“Now with the power supply problem “solved”, what happens? The population and the demand for power increases, and guess what? 2% just isn’t enough any more, now you need 4%. (Here comes the neck.) And after a few years, it’s 8% (the front legs), then 16% (the torso)… And how long is it before the whole camel’s in the tent, before solar panels cover everything that isn’t factory farm or city?”
Well, that’s where keeping the population somehow in check (peacefully, without disease, starvation, and involuntary sterilization, etc. – preferably with education, resources, and …) comes in. And the requirement that we have to pay the costs for stuff. And efficiency. I don’t think supporters of any solar plan would generally be averse to these things. (Limitations should be put in place to protect desert ecosytems, which would allow solar power desert installations to grow to some point. As technology per unit capacity becomes cheaper, greater power per unit land can be extracted with the sacrifice of less power per unit capacity. The potential value of farmland and rangeland for solar power and biofuel will raise the price of, among other things, beef, but that can be mitigated by less reliance on animal protein, and the use of runoff from solar plants to boost productivity of neighboring land, and that the long shadows cast by panels in the winter at mid-to-high latitudes does nothing to reduce photosynthesis of dormant plants covered in snow, and also, that biofuel technology can also be used to reduce the cost of growing food by offering a way to cut losses from crop damage, disease, spoilage, poor weather conditions too late in the season to switch crops, crop residues not fed to livestock, crumbs, used coffee grounds, etc.).
RichardC: – “My point is that there is plenty of desert to spare. A few percent for power production would just add to the diversity.”
Yes. It would not generally save a natural ecosystem unless it counteracted some other changes, but it would add diversity. We will have human-made effects, they might as well be aesthetic.
Mark – ““life on the edge”. In what way, when talking about desserts is this wrong?”
Well, I would expect that is true for the entirety of life, as it would be for some other extremes (high altitude, Antarctica, hot springs and deep sea hydrothermal vents, underground) – of course there will be some unique organisms in those places, but the entire biodiversity and biomass and/or biological nutrient cycling rates may be much reduced.
However, for individual organisms, life is pretty much on the edge anyway – if it’s not scarcity, it’s competition or disease, etc. Except (just barely) for the occasional first world human, his/her pets, gardens, livestock and crops.
David B. Benson
“By the way, horses are not closely related to bison.”
What I meant was that horse ancestors were in the Americas before they were brought back here, and something like bison (perhaps a relative of bison) was also here before bison were here.
Re 579 John P. Reisman – Nice!
“Except (just barely) for the occasional first world human, his/her pets, gardens, livestock and crops.”
Not to ignore that the livestock often pay for it.
———–
Making the photovoltaic layer has the advantage of reducing internal losses for a given material quality, so not only is less material required, but that material can be made more cheaply. (Losses within the photovoltaic layer include recombination of electron-hole pairs). Using a folded p-n junction can reduce necessary material quality by reducing opportunities for recombination, I think.
I hadn’t noticed that comment … the kind of diversity might well be associated with a lot of soil disturbance, etc, during construction. In other words a kind of diversity we already have too much of – disturbed soils laden with a fine variety of opportunistic invasive species that have a bad habit of swamping such sites all over the arid and semi-arid west.
On the other hand, there’s that kind of trashed habitat available all over the West … could just build there, instead.
Patrick 027 (604) — Bison bison is native to North America, a smaller version of the extinct Bison antiquus and the long extinct (early) steppe bison of the Pleistocene:
http://en.wikipedia.org/wiki/Bison
I don’t know the dates of the first B. bison fossil, but this is some help:
http://en.wikipedia.org/wiki/Ancient_bison
and
The ancient bison was somewhat larger than the modern subspecies, but a trend towards smaller body size is indicated by some early Holocene (10,000-6,000 years ago) intermediates that are usually assigned to a separate subspecies, the western bison (Bison bison occidentalis). Some authors contend that hunting by paleoindians was a driving force in this size reduction, but a similarly post-Pleistocene trend has been noted for the steppe bison in Eurasia (4). is from
http://osfosseisdosergio.blogspot.com/2006/07/bisonte.html
[reCAPTCHA offers sound advice with “ME humility”.]
Correction to 572: “My over point being:” should be “My overall point being:”
Correction to 605 (will be 604 when double post is removed):
“Making the photovoltaic layer has the advantage of reducing internal losses”
should be
“Making the photovoltaic layer *thinner* has the advantage of reducing internal losses”
591 (dhogaza)- “If you want to build your solar plant on top of Bonneville Speedway, hey, ecologically you’re not going to hear much of an argument.”
What’s really funny is I just thought of that in the last couple days, thinking about where the most ‘barren’ places are and noticing that bright white patch on a Weather Channel map.
But does the wind ever blow salt particles around there? That might be a corrosion hazard. (?)
592,593,602(will be 601 when the double post is removed) – very interesting, good points! Thank you.
“I only know because some anti-science republican wingnut senator from oklahoma is trying to block it”[sage grouse wind farm study]
Well, that could be anybody! :)
597 (Jim Bouldin) Thanks for that information; – “The mechanism for these increases is uncertain, but most likely represents either atmospheric and/or climatic enhancement rather than long term response to disturbance.”
Could it be said then they they haven’t reached maturity for the conditions?
“You are confusing sequestration with productivity there.”
I know the difference, but certainly admit to not being sure how any given ecosystem will rate on either scale.
“Wetlands have high productivity (NPP) but, with the exception of swamp forests, do not generally accumulate a lot of biomass (high NEP).”
What about peat bogs? (PS going way out on a tangent here, but a friend told me that fens are alkaline and bogs are acidic, and I was wondering if the plants involved act to cause that (perhaps in effect defending and spreading territory in the process) or if local mineralogical conditions determine which will form, or some combination of the two?)
Mark, temp and CO2 relationship is logarithmic because of some intuitive hot pipe analogy???
Jim Bouldin (597), others have said forest sequestration is not linear, trees absorbing much more during early growth, not so much as they mature, becoming almost nil the last few years. Does your reference article address this contention?
RodB, you could read the Abstract, which answers your question:
http://www.nature.com/nature/journal/v457/n7232/abs/nature07771.html
609 Mark, Rod.
For the range of time and temperature we are immediately concerned about the relationship has been found to be pretty linear.
“The researchers used a combination of global climate models and historical climate data to show that there is a simple linear relationship between total cumulative emissions and global temperature change…”
http://www.nature.com/nature/journal/v459/n7248/full/nature08047.html
The proportionality of global warming to cumulative carbon emissions
H. Damon Matthews1, Nathan P. Gillett2, Peter A. Stott3 & Kirsten Zickfeld2
“…we estimate CCR to be in the range 1.0–2.1 °C per trillion tonnes of carbon (Tt C) emitted (5th to 95th percentiles)…”
Add carbon; Increase temperature. End of discussion.
591 dhogaza, there are NO farms and NO cattle anywhere near my land. 15 miles to the south you’ll find them. To the north of me you’ll find mostly vacant land. Of course, undisturbed is a relative term. You’ll find dirt paths and there’s bullets in the sand and the occasional load of debris somebody didn’t want to take to the dump, but as far as the local wildlife is concerned, local mankind is far down the list of threats. Yep, the valley is different than it used to be – it was a swamp. Heck, my land isn’t “pristine” because of my neighbors’ 4″ wells. All that water creates an abundance of life where naturally there would be very little. Change isn’t always bad.
There’s been calls for having all the sage ripped out of the ground to allow the grasses more space. The points you bring up just reinforce my point – pristine land isn’t where the solar power stations would be built. They’ll be built close to towns and cities. As to other changes to the environment, well, that’s not exactly relevant to the discussion. We’re not really disagreeing, I think. I’m talking about what we have and where we’re going while you’re pointing out where things used to be. All’s valid.
As for your question about sage grouse – I’ve never seen one. I doubt they live in the San Luis – as I said, it’s friggin cold in the winter.
574 James says, “Now with the power supply problem “solved”, what happens? The population and the demand for power increases, and guess what? 2% just isn’t enough any more, now you need 4%. (Here comes the neck.) And after a few years, it’s 8% (the front legs), then 16% (the torso)… And how long is it before the whole camel’s in the tent, before solar panels cover everything that isn’t factory farm or city?”
[edit] what causes increased population. (The answer is poverty) Provide mankind with a reasonable standard of living and suddenly folks have 0 or 1 child instead of 7 or 8. Your scenario is [edit]
I am certainly in favor of applying the most stringent environmental standards to the construction of utility-scale, or industrial-scale, solar and wind power installations. As a society we failed to do so for fossil fuel development and we are experiencing the resulting damage. We should learn a lesson from that.
For example, solar power stations should obviously not be installed on relatively “untouched”, environmentally important, delicate desert ecosystems, particularly where threatened or endangered species may be involved. In my view these areas should be declared national parks or nature preserves and protected from any significant human impact.
The specific issues with wind turbines may be different — e.g. bird and bat kills — but the principle is basically the same. Obviously wind “farms” should not be built in the migration paths of endangered birds, for example, and the best possible technology for mitigating animal deaths should be mandated.
I am an animal rights advocate and a vegan for 21 years and I will probably be more inclined than most to oppose solar or wind projects that have egregiously harmful impacts on our fellow sentient beings whom we call “wildlife”.
Having said that, the fact is that human beings are going to continue for as long as we can get away with it to use some sort of technology to provide the energy that we need to sustain the comfortable and prosperous technological lifestyle to which we have become accustomed, or would like to become accustomed.
In my view the demand side of the energy equation is far more important than the supply side. We in the USA are obscenely profligate squanderers of energy to a degree that is, to be blunt, morally wrong. And to a great extent our rapacious consumption of energy — and 80 percent of the USA’s primary energy supply is fossil fuels — does not even serve us very well. Not only does it not really “enhance” our well-being beyond a certain point, but it contributes to serious problems like obesity and other symptoms of a pathologically sedentary lifestyle.
On the other hand, hundreds of millions of people all over the world are in real and desperate need of more energy. They have no electricity. None at all. Which means no access to any of the benefits of modern technology. They have to burn wood and dung and kerosene for heating and cooking and light and suffer from indoor air pollution as a result.
We, the rich, need to cut way back on our energy consumption. And much of the rest of the world needs more energy. Both sectors need to use whatever energy is available, as efficiently as possible.
There is some amount of energy which, equitably distributed and efficiently used, can sustain indefinitely some number of human beings in a comfortable, prosperous, modern, technologically advanced lifestyle, within the carrying capacity of the Earth’s biosphere, allowing for much of that biosphere to live and prosper in its own way free of human manipulation.
Whatever that amount of energy is, we will have to produce it somehow.
And it is clear that the technologies that are at hand, which can move us most quickly and safely away from fossil fuels and towards zero-carbon energy, with the least amount of other negative environmental impacts, are wind and solar and geothermal and hyrdo and biomass.
These technologies are available now and are ready to be scaled up as quickly as we want to do it. Currently available technologies are ready for the job. And their rapid ongoing development, particularly in solar, has incredibly exciting promise for delivering really vast amounts of cheap electricity.
Meanwhile, the smart-grid and storage systems that will facilitate getting more and more of our energy from a diverse mix of large and small, centralized and distributed, baseload and intermittent energy producers are also being rapidly developed.
The suggestion that solar power causes vastly more environmental damage than nuclear power is silly. Uranium mining alone causes massive long term damage to the very desert ecosystems that are portrayed as being devastated by solar power plants.
The suggestion that installing CSP on one or two percent of the USA’s deserts amounts to paving the continent with solar panels is inane.
The suggestion that wind turbines are more destructive to Appalachian ecosystems than mountaintop-removal coal mining is laughable.
Given the need to produce some substantial amount of energy from some technology to sustain some number of humans in a comfortable, prosperous, technologically advanced civilization, it is efficiency and clean, renewable energy combined that offer the least overall negative environmental impact.
That’s where we need to go, as quickly as possible, and that’s where we should be investing our resources — not in nuclear power and coal.
In case you think that intensive fossil-fueled based agriculture and industrialized factory farming of animals doesn’t have serious repercussions, see the following:
ANN ARBOR, Mich., June 19 (UPI) — The Gulf of Mexico’s oxygen-deprived “dead zone” could be one of the largest on record this summer, researchers at the University of Michigan say.
This so-called “dead zone” is expected to blanket about 7,980 square miles, an area about the size of New Jersey, Donald Scavia, a university aquatic ecologist, said in a release Friday.
It is possible to have equally productive agricultural systems without fossil fuels, but that would require a very different approach to agriculture than that currently promoted by the nation’s agricultural universities, which are almost wholly dedicated to the intensive fossil fuel-based model. Making such a transition, domestically, requires technical effort, but also government leadership in the form of real incentives that encourage private farmers to make the switch – something that the fossil fuel lobby earnestly opposes in Congress.
This is of even greater importance to developing nations, who simply won’t have access to cheap fossil fuels in the future for even the most basic work, such as pumping water for irrigation. Solar-powered water pumps, electric tractors and other innovative small-scale technology are what developing-world farmers really need – but that doesn’t fit the western fossil-fuel-based industrial model, so such efforts are not promoted by USAID, the World Bank, or other international development agencies funded by the industrialized nations. If they were, the fossil fuel lobby would certainly push to have such agencies defunded by Congress.
Hopefully, that shows that solving these problems requires coordinated efforts, and that it is not, as the public relation industry claims, “a matter of personal responsibility”.
If you disagree, consider the era before public sanitation (sewers, sewer processing plants, etc) existed, when human excrement was simply tossed into the streets to be washed away by the rain. This was also known as the ‘cholera era’, and can still be found today (there was a recent outbreak in Iraq).
Would ‘personal responsibility’ solve that problem? If you carefully dealt with all your own personal waste, would the city be free of cholera? Of course not, because it only takes a relatively small number of people to perpetuate the problem. Instead, you need sewers that reach every single house in the city – and no one is allowed to dump their excrement in the streets, even if that is “an infringement on personal liberty.”
The same general concept applies to the high levels of primarily industrial agricultural effluent that kills off the Gulf of Mexico each year – and it’s not just the Gulf of Mexico anymore, it really is becoming a global effect, with hypoxic zones appearing in many different regions:
http://www.usatoday.com/tech/science/2008-08-14-3253832470_x.htm
Patrick: “Could it be said then they they haven’t reached maturity for the conditions?”
Yes, an excellent way of putting it. There’s a disequilibrium, or forcing, and the forests are responding to it. In Africa, the forcing appears to be either CO2 fertilization and/or climatic changes (my hunch would be mainly the former, but it would be just that, a hunch).
““What about peat bogs?…a friend told me that fens are alkaline and bogs are acidic, and I was wondering if the plants involved act to cause that (perhaps in effect defending and spreading territory in the process) or if local mineralogical conditions determine which will form, or some combination of the two?)”
Yes, peat bogs would count, the seq. rate would likely be low (cool to cold, oxygen-poor, acidic substrate) compared to anything with woody vegetation and/or aerated soils. Bogs are definitely acidic, but going strictly from memory, I don’t think fens are necessarily alkaline. The main difference between them is stagnant vs flowing water. Yes, the plants in a bog strongly influence the acidity, probably fully determines it in most cases, although I suppose there could be cases where the bedrock contributes something too.
Rod: The statement is more or less correct (more exactly, they grow fastest when their ratio of leaf area to respiratory tissue is maximum, the timing of which varies depending on several factors). The ratio of photosynthetic C production to respiratory C use (P:R) approaches 1 (bare maintenance) as a tree gets larger, for biophysical reasons (leaf area increases slower than respiratory tissues do). What’s interesting about the Lewis paper, which was focused on documenting the C increases (being a synthesis of inventory data collected over 40 years across several tropical African countries), is that they find that trees are still growing, and so presumably are not close to their P:R limit. But why? They addressed this partially, by presenting evidence regarding the nature of the disturbance regime, finding that large scale disturbances in the past were unlikely, and hence, the likelihood that the observed C increases were due to a rebound therefrom was also unlikely, and hence the increase in biomass was likely due to the remaining possible causes: CO2 fert. and/or climatic changes. There have been other papers over the last decade finding similar C increases in the Amazon, and also in some temperate forests. But there have also been some important ones finding the opposite (e.g. the van Mantgem et al (2009) paper that I wrote a story about back in February).
Hank, I couldn’t find my answer in the abstract — only mean average sequestration over 40-some years.
Mark,
The example, you give, of lagging on a hot water pipe is one of a decreasing exponential too. It isn’t logarithmic.
In the limit when the thickness of the insulation tends infinity the heat loss tends to zero. At the other limit when the thickness of the insulation is zero the heat loss is still finite. Not infinite as you’d get from a logarithmic relationship.
True the plot of a logarithmic realtionship and a reducing exponential relationship would look very close over much of the range but that’s as far as it goes.
Looking at what happens at the limits, the extremes, is always a good test of any physical equation.
You ask me why I want to know? That seems a very strange question to ask. How about scientific curiousity? Will that do for an answer?
I’m not a contrarian if that is what is concerning you. I do accept that the dangers of AGW are very real and I am concerned that an overuse of the logarithmic function is allowing certain groups to understate those dangers.
I tried to respond to RichardC’s ignorance, and it got flagged by spam.
Spam filter’s are fine but … why after being informed, if I try to go back to correct, is the whole post deleted?
It’s not like the spam filter has 10% the intellect of Anthony Watts.
Meanwhile, one statement:
Of course, they’ve been extirpated due to anthropogenic impact, as I would assume an intelligent person would have managed to understand from the information I posted above.
The only place sage grouse live is where it’s friggin’ cold in winter. That’s their habitat, christ on a crutch …
This is something that REALLY PISSES ME OFF. If you’re so ignorant that you argue that you live on ecologically pristine land while saying “I’ve never seen a sage grouse” which is native to that habitat and only absent due to anthropogenic changes, including historically known HEAVY GRAZING BY CATTLE, etc.
You are not qualified to differentiate an unaltered desert habitat from an underground Manhattan parking structure.
Just saying.
You’ve exposed your ignorance here. I think your heart is in the right place, but please, learn some desert ecology. You own 160 acres out there and you’ve not bothered to learn what the native pre-grazing habitat was like? And now lecture us about “oh, sage grouse don’t live here because it’s too cold”? Total bullshit?
Forget global warming, for the moment. Go learn some sage-steppe ecology and do your bit for habitat restoration.
Crap, I’ve debated with big-time cattle operators for years and I’ve never heard the level of denialism you express. They tend to be honest – “gotta make my living, even if I know sage grouse didn’t die because it got too cold”.
Sheesh.
dhogaza Says (20 June 2009 at 1:04 PM):
“The claim that there are huge swaths of land in the arid and semi-arid portions of the west that are largely untouched by human impact is simply false.”
True enough, at least in my observation. But even if it has been changed (often for the worse, to my taste at least), it still remains a living ecosystem.
“What this actually means of course is that there are millions of acres of heavily-impacted land available for solar power…”
No, what this means is that there are millions of acres that could use some habitat restoration. What you seem to be saying is that because it’s been somewhat messed up, so it’s no longer pristinely “natural”, then it’s ok to go ahead and destroy it?
PeterMArtin,
You are correct that the CO2 forcing is not logarithmic at very low concentrations (or very high ones, in fact) but such conditions are not relevant at Earth-like climates (at least over the last few hundred million years or the forseeable future) and thus the standard formulas for forcing (e.g., Myhre et al 1998) are suitable over the terrestrial climate regime. The reasons for this logarithmic forcing involve the exponential decay of the absorption in the principal bands, and this is explained in Ray Pierrehumbert’s book in chapter 4.
re 614:
SecularAnimist makes the following statement: “There is some amount of energy which, equitably distributed and efficiently used, can sustain indefinitely some number of human beings in a comfortable, prosperous, modern, technologically advanced lifestyle, within the carrying capacity of the Earth’s biosphere, allowing for much of that biosphere to live and prosper in its own way free of human manipulation.”
In theory, this is an unexceptinal statement but one that needs some qualification. Could SecularAnimist attach a relevant figure to the “some number” of people who could live sustainably in the way he envisages? In particular, would the figure exceed 8 billion, that which we are scheduled to reach in 2050? If not, equitable distribution of energy would probably ensure the mutually assured destruction through starvation of the human race and certainly not leave the rest of the biosphere to prosper in the manner he wishes. In any event, perhaps he could explain what political system he would advocate to achieve the equity he seeks and comment on whether he considers it compatible with our evolved, competitive natures.
I support SecularAnimist’s objective. If I had to guess at the sustainable human population, living in the way he would like, and leaving plenty over for other species, I would arrive at a figure of 1 to 2 billion. To arrive at this figure, starting at 6.7 billion and increasing to more than 8 billion before ultimately falling back to reach it, may or may not be possible, particularly against a background of peak oil and AGW. I wish I had his confidence that all this can be achieved by transitioning to a more costly energy system than the current one. I believe the only hope to be from an energy system that is actually cheaper than that which we now have. I am hoping that this will be provided by sodium cooled fast reactor technology but accept that this may be wishful thinking. If I’m wrong, renewable energy will probably allow some of us to survive for a bit longer. Perhaps, a massive die off through famine, war and disease is just what is needed as a prerequisite for the state of affairs that SecularAnimist is hoping for. However, lacking his idealism, I shall do my best to behave selfishly, as a good animal should, to ensure the survival of my own genes rather than those of others. Unfortunately, I haven’t yet found an appropriate strategy to give me the confidence that it has much chance of success.
Patrick 027 Says (20 June 2009 at 3:18 PM):
“But now Cool Earth Solar of Livermore, California, has come up with what it hopes will be a better, cheaper alternative: balloons.”
Drat! It’s the same old story: someone always comes up with my great ideas before I do. Now I know how Wallace felt. (Alfred Russel, not George.)
“…an alternative could be to use fixed spherical or circular-cylindrical mirrors on the ground…”
But the whole point is to get the solar generators off the ground, and to a high enough altitude that they don’t completely block sunlight from the land below. Getting them to high altitude also puts them above most clouds.
Apparently tethering things at that altitude isn’t impossible, as here’s a recent proposal to put wind generators in the jet stream: http://www.businessgreen.com/business-green/news/2244394/flying-researchers-target-jet
So if you have a half-silvered balloon, gas pressure should make it approximately spherical at altitude, so it would focus the light on to a small patch of photocells (which IIRC are more efficient at colder temps, another plus). A small movable weight tilts it to track the sun in the horizontal plane, while a controllable wind vane would rotate it around the vertical axis. Waste heat helps keep it inflated, and I think might radiate better, yielding a slight reduction in warming as a side effect.
RichardC Says (20 June 2009 at 7:46 PM):
“…what causes increased population. (The answer is poverty) Provide mankind with a reasonable standard of living and suddenly folks have 0 or 1 child instead of 7 or 8.”
Sorry, no. Methinks you need a little lesson in the birds & bees :-)
Or perhaps in simply looking at real-world data. Yes, that “prosperity reduces population growth” meme is popular among the apologists for consumerism, but where is the actual evidence? Here’s a link to growth rates by country: Up near the head of the list you’ll find some of the wealthier countries such as Kuwait, the UAE, and Ireland. The bottom – and the only ones with actual negative rates – is mostly filled not with rich countries, but with members of the former Soviet Bloc.
http://en.wikipedia.org/wiki/List_of_countries_by_population_growth_rate
SecularAnimist Says (20 June 2009 at 8:11 PM):
“The suggestion that solar power causes vastly more environmental damage than nuclear power is silly.”
Yeah, when you’ve got a fixed belief system, any facts that conflict with those beliefs are silly :-)
“Uranium mining alone causes massive long term damage to the very desert ecosystems that are portrayed as being devastated by solar power plants.”
Where on Earth do you get your ideas from? Even open-pit uranium mines cover relatively little area, and once the mining operations are finished, they can be restored. Underground mining requires only a small amount of surface, which again can be restored when mining is finished.
But in fact, both of these have largely been replaced by a process called in-situ leaching, which has only a small effect on the surface: http://www.world-nuclear.org/info/inf27.html
“# Rod B Says:
20 June 2009 at 6:42 PM
Mark, temp and CO2 relationship is logarithmic because of some intuitive hot pipe analogy???”
No.
Why do you think that?
It does illustrate that a linear relationship won’t work, though.
I would ask you to illustrate what the mathematics is, but given that comment I suspect you’re too functionally illiterate to manage that task.
Nigel, I think the other fella was talking about the doubling of CO2 produces a linear change in temperatures.
Which is a logarithmic relationship.
But for small changes, it’s linear.
Rather like a small section of opaque atmosphere will, say, remove 1% of the light. The next small section also removes 1% of the light. This is linear.
BUT because the light that gets to the second section is already reduced, the second section is removing 1% of the remaining 99% of light.
And the third section is removing the 1% of that 99% of 99% it gets.
And so on.
And THIS is a logarithmic progression (dX/dl=1/constant occurs when X=log(l)).
From a linear constant reduction over a small displacement, the relationship of the result over a large displacement is logarithmic.
“Mark – ““life on the edge”. In what way, when talking about desserts is this wrong?”
Well, I would expect that is true for the entirety of life, as it would be for some other extremes (high altitude, Antarctica, hot springs and deep sea hydrothermal vents, underground)”
Well that would explain why daghoza doesn’t like that phrase, but it doesn’t actually make it wrong, does it?
And I do not think it would be true for the entirety of life, but life in other extremes WOULD be. After all, they are extreme environments, not paradisaical ones. Else we wouldn’t have given them a different name…
613 – Those edits were uncalled for. My comments were proper and on topic. I’m feeling picked on! ;-)
RodB,
Trees sequester carbon in two ways. First in their trunks and branches. That increases mostly in youth and ends on death until the tree falls over and rots. They also sequester carbon in their leaves, and that increases as they grow and remains high until near their death. The leaves rot and return the carbon to the air, but much does not rot and forms leaf litter or boggy swamps. In the extreme case during the Carboniferous geological period the trees in much swamps drew down so much carbon that there was an ice age. We are now putting that carbon back into the atmosphere when we burn coal.
HTH,
Cheers, Alastair.
“PeterMartin Says:
20 June 2009 at 23:35
Mark,
The example, you give, of lagging on a hot water pipe is one of a decreasing exponential too. It isn’t logarithmic.”
Nope. It’s not decreasing exponential (and I note you haven’t said what the heck THAT means scientifically), it’s logarithmic.
At least as far as energy loss is concerned.
AND it wasn’t an accurate simlulant of the problem asked, AS I SAID IN THE BEGINNING OF THE BLOODY POST YOU READ!
It’s an analogue.
It shows that linear wouldn’t be right.
And that a doubling of thckness could well result in half the loss of energy, making the lagging and energy loss reduction logarithmically dependent.
And so much effort has been wasted and you haven’t answered the queries.
We still don’t know if the full-on quantum explanation will sail straight over your head. We still don’t know why you think it isn’t logarithmic (e.g. why do you believe a handful of scientists but not a roomful?). And so on.
James wrote: “Yeah, when you’ve got a fixed belief system, any facts that conflict with those beliefs are silly”
You have provided NO facts — none at all — to support your ridiculous assertion that solar power is more environmentally damaging than nuclear power.
So much more damaging, in your opinion, that nuclear war would be preferable to installing solar power stations on one percent of the USA’s deserts.
You just keep making the same baseless assertions supported by other baseless assertions and ill-informed assumptions.
And you don’t honestly engage with what others actually say. When I cite a study showing that installing concentrating solar thermal power plants on one percent of the USA’s desert land could power 90 percent of the grid plus electric cars, you respond that I want to pave the entire North American continent with solar panels. Let’s call that movie “James vs. Strawmanzilla”.
When someone presents facts that don’t support your “fixed belief system”, you don’t respond to the facts — you accuse them of being part of an anti-nuclear religious cult.
Meanwhile, you systematically exaggerate the problems of renewables while pretending that the very serious problems of nuclear power don’t exist.
Look, I understand that nuclear enthusiasts are nuclear enthusiasts. Some people want nuclear power because, well, because they dig it. That’s cool. That’s fine.
But the facts just don’t support the argument that nuclear power is better than renewable energy, or that mountain-top removal coal mining is less environmentally damaging than wind turbines, or any of the other baseless assertions that you keep glibly repeating.
The facts don’t even support the argument that nuclear power is a necessary, or desirable, or effective, or affordable solution for reducing GHG emissions from electricity generation.
The facts show that renewables can do the job — and are already on the job, growing at record-breaking double-digit rates year after year, enthusiastically backed by venture capital, major utilities and corporations, and increasingly encouraged by enlightened government policies.
Meanwhile the “new generation” of nuclear power plants is mired in the same multi-year delays, multi-billion dollar cost overruns, and safety problems that have plagued nuclear power for a half-century.
My expectation is that well before any “nuclear renaissance” begins to actually deliver any significant amount of power from new reactors, that renewables will have grown so much that they will eclipse nuclear power as an energy source.
… Thinking about water use: If it can be shown (as I expect it can) that the energy for desalination of seawater and pumping it uphill and inland by some standard amount is a small fraction of the energy produced by a solar plant using the same quantity of water, that would bode well. Of course, some of that water will runoff and could be used for another purpose. (If the water is additional to the rainfall in the region, some fraction of the evaporation of that water would, depending on drainage patterns and winds, be recycled and add to the rainfall.)
But then again, the cooling water that flows through a typical coal power plant is still there after use – it is warmer, there can be a local heat pollution issue, and it will evaporate faster than otherwise, but it isn’t wholly used up.
Nuclear power uses cooling towers; my understanding is that all the cooling water must evaporate? Some portion will be lost from the region depending on winds and drainage patterns. On the other hand, some will come into the region from other power plant evaporation.
So I guess now I’m not sure how the water issues work out; except perhaps that nuclear power tends to need more liquid water on hand…(?)
Jim Boulding 616 (could turn into 615) – Thanks; great info!
Re 624(James) – Thanks.
Would those balloons be in the stratosphere (to avoid cumulonimbus convection)?
I offered the other concept (fixed mirrors, moving foci) because it occured to me that it might simply the tracking mechanism requirements.
Re 623(Douglas Wise): “In any event, perhaps he could explain what political system he would advocate to achieve the equity he seeks and comment on whether he considers it compatible with our evolved, competitive natures.”
Human nature is a mixed bag. We aren’t bees, but we aren’t Humboldt squid either.
SecularAnimist Says (21 June 2009 at 10:47 AM):
“You have provided NO facts — none at all — to support your ridiculous assertion that solar power is more environmentally damaging than nuclear power.”
On the contrary: I’ve provided plenty of facts, from the simple logic that says blocking sunlight & spraying herbicides is not a recipe for environmental health on up. You’ve just (figuratively) stuck your fingers in your ears and repeated “I can’t HEAR you”.
“So much more damaging, in your opinion, that nuclear war would be preferable to installing solar power stations on one percent of the USA’s deserts.”
You also need to work on your reading comprehension, because what I wrote is that nuclear war would be preferrable to a world that’s paved over with cities, solar plants, and industrial agriculture.
“And you don’t honestly engage with what others actually say. When I cite a study showing that installing concentrating solar thermal power plants on one percent of the USA’s desert land could power 90 percent of the grid plus electric cars…”
A study from a company seeking investment capital to build those plants? Don’t I recall, from a previous thread, a certain degree of scepticism regarding the objectivity of industry-financed research? But of course that doesn’t apply when it gives the results YOU want :-)
Then there’s that Scientific American study, which finds that it would take roughly 3% of the entire (continental) US to do the same thing. Which am I supposed to believe?
Now if we want to go into the question of “baseless assertations”, how about your assertation regarding uranium mining? It should be a simple matter to compile a list of present & past mines, add up their surface areas, and supply a link, but have you done this?
“Meanwhile, you systematically exaggerate the problems of renewables while pretending that the very serious problems of nuclear power don’t exist.”
Nope. I point out the fairly obvious problems with renewables that you gloss over in your enthusiasm, and show that many of the alleged problems with nuclear are (charitably) not evident in practice.
“Look, I understand that nuclear enthusiasts are nuclear enthusiasts. Some people want nuclear power because, well, because they dig it.”
(Sigh) But I’m not a nuclear enthusiast. I’m only concerned with results: how to get sufficient power at reasonable cost without trashing the environment. Nuclear (as part of a mix) does that. Nothing else that I’ve ever seen will.
“But the facts just don’t support the argument,,, that mountain-top removal coal mining is less environmentally damaging than wind turbines…”
But when have I ever made that claim? The closest I’ve come is to point out the (fairly self-evident, I would think) fact that the wind turbines are going to be a permanency, while a played-out coal mine can be rehabilitated into a functioning ecosystem.
“The facts show that renewables can do the… job increasingly encouraged by enlightened government policies.”
= subsidies. Which is another way of saying that if it weren’t for tax breaks &c, nobody would be building those wind farms or desert solar plants.
Patrick 027 Says (21 June 2009 at 12:49 PM):
“Nuclear power uses cooling towers; my understanding is that all the cooling water must evaporate?”
No. It depends on the design of the cooling. t’s really just thermodynamics. Any heat engine, be it nuclear, coal-fired, geothermal, or solar thermal, needs cooling, because heat engines run on temperature differences. If your plant is located next to an ocean or lake, you can use that for cooling (consider nuclear submarines…). If you have plentiful water, you can use evaporative cooling. In a dry area, you can use a closed-loop system that rejects heat to the air.
I’m getting pretty darn tired of not-fully-named James. He’s a clever fellow, and able to reason sometimes, and apparently takes the position that when kicking around big issues we should not restrict ourselves to prissy PC statements. So do I. So he goes on to favor, in at least some circumstances, nuclear war over any large amount of solar power on deserts. Well, that’s fine and dandy for 2AM in the dorm, but I haven’t lived there for some decades, and my finger is getting tired just from scrolling past all the unsupported speculation. How did we get from 1 or 2% of certain areas covered to a disaster worse than nuclear war? James doesn’t say, just some hand-waving about parables (#574, camel’s nose). Having had one moderate nuclear war, how do we know it doesn’t lead to various barely imaginable horrors with more certainty than the camel’s nose of desert solar? James doesn’t explain, for the obvious reason that no one on earth could ever do better than wild speculation on something so uncertain and unprecedented. If you’re going to get into world energy policy, at least acknowledge the huge array of interacting choices, and discuss them with some humility about the unknowns, having absorbed the choices at least on the level of, say, Joe Romm’s Climate Progress blog, together with the transitive closure of its nearly limitless references. That goes for James and everyone else.
Rod B, see if this helps:
Luyssaert, S., E. D. Schulze, et al. (2008). “Old-growth forests as global carbon sinks.” Nature 455(7210): 213-215.
available at:
http://www.borealbirds.org/resources/study-nature-oldgrowth.pdf
James (626) — Please read “Radioactive Revival in New Mexico”, by Shelley Smithson, in the 2009 Jun 29 issue of The Nation regarding the results of mining uranium.
Hint: Ain’t pretty.
From: https://www.realclimate.org/index.php/archives/2009/03/with-all-due-respect/langswitch_lang/fa#comment-116099
Regarding a solar thermal power plant with central recievers and many heliostats:
Assuming a capacity factor of 1/4 (the stated 400 MW seems to be a capacity; capacity factor = average power / capacity), osmotic pressure of sea water less than 30 MPa (less than about 30 atmospheres), and that the amount of water used by the power plant is to be desalinated and pumped upward 1000 m in a 33.3 % efficient process, less than 0.1148 % of the energy from such a power plant would be used for desalinating and pumping water. Getting all electricity from such power plants would use about 1.08 gallons of water per person per day with present day energy usage in the U.S (0.4748 TW of electricity in 2007 (0.4573 TW of that from the electric power sector), approximately 300 million people). (and much of that water would not be ‘used up’ by the process).
Water use is about 6.33 mm/year or 0.25 inches/year over the area of the power plant.
Perhaps more generally, rainfall on solar panels or mirrors could be made to drain towards collectors at the bases of those devices?
James –
I’ve been going back over the “Solar Grand Plan” numbers. They wanted to be conservative in establishing feasibility, so they assume a 1 % increase in energy demand per year.
This article is from 2008. So I use 42 years until 2050 and 92 years until 2100.
U.S. population is now about 300 million people. It seems reasonable that U.S. population may grow to 400 million in 2050 (in fact I think that is about the projection from the CIA – or maybe 405 million). Suppose it reaches 450 million in 2100.
Energy use increases by a factor of 1.52 from 2008 to 2050 and 2.50 from 2008 to 2100, while population increases by factors of 1.33 and 1.5 over the same periods. So per capita energy use increases by factors of 1.14 and 1.67 over those periods.
That’s their scenario.
On the other hand, per capita energy consumption has remained about flat over the last 3 decades. I think electrical power consumption has increased faster than non-electrical power consumption.
Now here’s where things get tricky – the Solar Grand Plan article does not appear to convert solar electricity into a thermal fuel equivalent for accounting, so they state that while energy demand increases, energy consumption actually declins a little in the first 42 years (to 2050). Another wrench in the equation is that they have some portion (perhaps nearly all?) of energy consumption by transportation being solar electricity by 2050. Which is potentially a very good thing, but it makes the math trickier.
They also give capacities of power rather than average power output.
Some clarifications are made in the comments.
I’m going over it, but I suspect the actual area needed by 2100 could be reduced to 1/3 of their stated area.
You’re not a nuclear enthusiast?
Your words speak a different story, James.
David B. Benson Says (21 June 2009 at 2:52 PM):
“James (626) — Please read “Radioactive Revival in New Mexico”, by Shelley Smithson, in the 2009 Jun 29 issue of The Nation regarding the results of mining uranium.”
Read it. Long on emotion, short on facts. As for instance, how does past uranium mining differ from any other mining? For instance, there’s this one http://en.wikipedia.org/wiki/Almaden_Quicksilver_County_Park where I’ve done a bit of hiking. Or this http://en.wikipedia.org/wiki/Comstock_Lode just over the hill from me (and the local hills have literally hundreds of small mines & exploratory shafts from that era). This one http://yosemite.epa.gov/r9/sfund/r9sfdocw.nsf/vwsoalphabetic/Leviathan+Mine?OpenDocument is just down the road a bit, this one’s http://ndep.nv.gov/yerington/history.htm about an hour’s drive.
Then there is plenty of ongoing mining around here. Gold is big http://en.wikipedia.org/wiki/Gold_mining_in_Nevada but there are mines producing a range of minerals from gypsum (got sheetrock in your house?) to lithium (all those laptop batteries) to opals. So why’s uranium any different than any of these?
Mark Says (21 June 2009 at 4:56 PM):
“You’re not a nuclear enthusiast?
Your words speak a different story, James.”
Well, as I keep saying, some people need to work on their reading comprehension :-) If I’m an enthusiast for anything, it’s for having a nice world to go on living in. Show me something that seems more likely to accomplish that, and I’ll be happy to hop on the bandwagon. But you do need to have some sort of evidence…
James (644) — Given you last question, you could not have read the article with much attention.
So try again and then go find out some information about the effects on ground water of the various forms of mining, the effects on miner’s (and others) health of various forms of mining, etc.
Try Butte, MT, and Silver Valley, ID, versus NW New Mexico. Some forms of gold mining are not so bad. Look into the mercury extraction techniques being used in parts of South America.
dhogaza, Stop with the “pristine land” stuff. I’M NOT SAYING MY LAND IS PRISTINE! And stop grousing about grouse. I’m looking at the historical range map and it shows that my land is just outside their historical range. Your point just failed.
http://www.fws.gov/mountain-prairie/species/birds/sagegrouse/map_sagegrouse_range2000.JPG
636 James said “the wind turbines are going to be a permanency, while a played-out coal mine can be rehabilitated into a functioning ecosystem.”
uh, a played-out coal mine means that ANOTHER mountain MUST be destroyed.
Mark,
You say “Um, isn’t a reducing exponential relationship merely a polynomial fit???”
No.
Going back to your example of heat loss from a lagged pipe you can say the heat loss is given by:
H=H0(1-exp(-t/d))
H0 and d are constants. t is the thickness of the lagging. When t=0, H=H0. And, when t is very large H=0. Just like you’d expect.
If you plot out the function, you’ll see that there is a linear looking region at low values of t, then a region which is more logarithmic looking at higher values.
If you try to describe the heat loss by a logarithmic function you don’t get such a sensible outcome at the limits. As I said previously you get infinite heat loss in the limit of zero lagging thickness.
It may seem a pedantic quibble but I’d like to see some recognition that at zero CO2 levels the earth’s temperature would not plunge to -infinity!
Besides that, the contrarians are using a logarithmic relationship to claim that whilst CO2 is an important GHG, and contributes significantly to the total natural level of 33 degC, that this almost entirely happens at very low concentrations. ‘Almost entirely’ is an obvious exaggeration. But it can be justified on the grounds that every time CO2 levels are halved the temperature will change by the same amount as when they are doubled. This certainly would be the case if the relationship was logarithmic.
#645 James
Well, having less weapons grade plutonium on the market would give us a reasonably better shot at it.
You don’t need evidence for the future potentials of nuclear war in a resource scarce world, you need to be intelligent.
Peter, but the doubling is less significant an increase at low concentrations.
This balances out.