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HumanityRules at 13:13 PM on 16 April 2010Earth's five mass extinction events
31.cbrock What you think NewScientist choose to include that phrase themselves? Seems unlikely from a level headed publication, if true it's possibly worse given NS has more impact than a single scientist -
Doug Bostrom at 12:55 PM on 16 April 2010Earth's five mass extinction events
Here we go, another log on the cheery fire of discussion: Increasing concentrations of carbon dioxide in sea water are driving a progressive acidification of the ocean1. Although the associated changes in the carbonate chemistry of surface and deep waters may adversely affect marine calcifying organisms2, 3, 4, current experiments do not always produce consistent results for a given species5. Ocean sediments record past biological responses to transient greenhouse warming and ocean acidification. During the Palaeocene–Eocene thermal maximum, for example, the biodiversity of benthic calcifying organisms decreased markedly6, 7, whereas extinctions of surface dwellers were very limited8, 9. Here we use the Earth system model GENIE-1 to simulate and compare directly past and present environmental changes in the marine realm. In our simulation of future ocean conditions, we find an undersaturation with respect to carbonate in the deep ocean that exceeds that experienced during the Palaeocene–Eocene thermal maximum and could endanger calcifying organisms. Furthermore, our simulations show higher rates of environmental change at the surface for the future than the Palaeocene–Eocene thermal maximum, which could potentially challenge the ability of plankton to adapt. Rate of ocean acidification the fastest in 65 million years Now mind you, the actual paper title is "Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release" but who am I to deny a blog titled "Desdemona Despair" its little bit of fun? Besides, the more punchy version is after all the title of the press release from U. of Bristol and "fastest in 65 million years" is after all the result. So paleo data, models, a sexy press release. What's a rejectionist not to like? ;-) -
watchingthedeniers at 11:01 AM on 16 April 2010Earth's five mass extinction events
@ 35 thingadonta A version of the naturalistic fallacy? Just because "Event A" happened under "natural conditions" over XXX Ma does not preclude it happening in the short term future. Accelerated release is not contingent upon causation being either "natural" or "human induced". What matters is the chemistry/physics. One would think the idea of positive feedback loops (release of the reserves of Co2 and CH4 when we reach the right "tipping point")) are crucial to understanding the issue. -
thingadonta at 10:50 AM on 16 April 2010Earth's five mass extinction events
#23 Steve RL. "So apparently conditions not conducive to coraline growth (low pH) persisted". IE for ~10Ma. In the case of coals, there is a 'coal gap' between 250 Ma to ~240 Ma, the plant species that produced most of the coal in The Late Permian went extinct at the end of the Permian and had to re-evolve-, so there is virtually no coal on the East Coast of Australia from about 250-240Ma(ie from the Sydney-Bowen Basin-which royalties pays a reasonable proportion of East Coast academic salaries-you don't hear much appreciation though). Coal produced after 240Ma was from different plant species than previously, you also get a lot of red beds at this time indicating hothouse conditions. But my point is, all this took hundreds of thousands- to millions of years of vast amounts of c02 etc from Siberian Traps volcanism-oceans didnt,and probably won't, acidify quickly-ie less than tens of thousands of years?, if they do from humans at all. -
watchingthedeniers at 10:41 AM on 16 April 2010Earth's five mass extinction events
@ Philippe Chantreau post 32 Are we talking about the K-T boundry line here and the creataceous mass extinction event? I thought his was regarded as the mainstream/consensus view. I understand there is still some debate on the issue. What is the most recent peer revieweed lit on this? However, SciAm referenced a study here as the "definative consensus view" on the issue.: "...A group of 41 researchers have pored over the evidence and decided that—in accordance with the original postulate put forth 30 years ago by a team led by father and son researchers Luis and Walter Alvarez—it was, indeed, a massive asteroid that slammed into Earth, creating Chicxulub Crater on Mexico's Gulf Coast, that killed off many of the species on the planet, including the non-avian dinosaurs. The review, published online March 4 in Science, evaluated the whole picture, according to Kirk Johnson of the Research and Collections Division at the Denver Museum of Nature and Science and co-author of the paper. And that meant assessing the other theories that have been put forth about what spelled death for the dinosaurs..." Study published in Science here : "...The temporal match between the ejecta layer and the onset of the extinctions and the agreement of ecological patterns in the fossil record with modeled environmental perturbations (for example, darkness and cooling) lead us to conclude that the Chicxulub impact triggered the mass extinction." [from abstract] -
thingadonta at 10:39 AM on 16 April 2010Earth's five mass extinction events
Thanksfor the link paper, One question before I may respond more fully (I am in the remote field at the moment using VSAT satellite collecting real data in the real world, and not making up pretty coloured models on a computer screen, and of course, who am I having to deal with right now, people using pretty coloured maps on a computer screen which are wrong and exagerated and which I am fixing in the field with real data, but I digress). my question: -the Siberian Traps ejected vast volumes of eg c02 over several hundred throusand years+, and it took coral reefs to collapse over hundreds of thouands of years (and possibly, oceans to acidify-although this is not clear) hso how can less amounts of c02 from humans acidiy the oceans in a few decades-hundreds of years?? -
michael sweet at 10:05 AM on 16 April 2010Flowers blooming earlier now than any time in last 250 years
JohnD. It is certainly possible for new methods to be developed. As I mentioned, new cultivars can be developed. I have 4 peach trees here in Florida for example. However, it is expensive and risky to have to develop new culltivars constantly to keep the produce coming. What will these changes cost? Are the new varieties as good as the old ones? Are farmers willing to take on the risk? Some changes cannot be managed: cherries need a lot of chill and I have not seen low chill varieties. Natural forests do not have the option of developing new trees. The old trees will die off and be replaced by trees adapted to the new conditions-- if the new conditions last long enough for them to grow. It seems to me that a better approach is to minimize change to minimize adaption expense. It may be more costly to adapt than to reduce carbon emmisions. -
yocta at 09:39 AM on 16 April 2010Flowers blooming earlier now than any time in last 250 years
RE# johnd 83 I never thought my favourite Fuji could be so interesting! This is an interesting paper I just found about apples in Java, albeit slightly dated. (Rosmahani et al. 1988) And if I quote from parts of it “...The first successful cultivation of apples in Java was recorded in 1934 (Rosmahani et al., 1988), but it took more than 40 years for research in apple culture to achieve its present development. One of the challenges in growing temperate fruit in the tropics is simulating mechanisms that prevent bud dormancy in the absence of temperature and daylength variation.... Like most exotic species from temperate origins, in the tropics apple trees are vulnerable to pests and diseases. The high humidity of tropical mountains allows for the growth of certain fungal diseases that destroyed most of the apple trees in Java during the 1970s. Present cultivation of apple trees relies on the frequent application of heavy doses of pesticides and fungicides.” So yes I agree it is quite marvellous that the farmers have developed techniques, I am not share your optimism about the suitability of the land use overall for these particular crops, as the paper concludes: ...Instead of developing into a system with a high biological diversity that requires low inputs, apple-based farming systems are increasingly simplified, allowing only a limited choice of intercrops. The system also relies heavily on chemical inputs... -
Tom Dayton at 09:36 AM on 16 April 2010Models are unreliable
Yep, pdt, I agree with you that the accuracy of the predictions likely will be lower than for the fit. So researchers keep trying to reduce the numbers of parameters they use, and to improve the estimates of the parameters they must use. The claim (not yours!) I was initially responding to was the misperception that the climate models' predictions are evaluated against the same data that the models were statistically fit to in the first place. By the way, there is more discussion of parameterization on Open Mind, especially starting with Ray Ladbury's comment. When you get down to Tim's comment below Ray's, skip it because Tim then posted a correction and then a final correction. -
scaddenp at 09:24 AM on 16 April 2010Are we too stupid?
And how much of a no-brainer is ending any kind of subsidy on any industry that is a CO2 emitter? I am well aware that this will result in unemployed coal miners, etc - deal fairly to them by all means but their jobs are not a reason for messing the planet. -
scaddenp at 09:19 AM on 16 April 2010Models are unreliable
pdt, you seem to implying that models "tune" the parameters to match climate, but the parametrization is done independent of the models, and the values used in the model. Also note that it is not blind fitting of a statistical function but usually determining the empirical value of coefficients in a functional form derived from the physics. Note also that for some (like clouds), the parametrization can be checked against output of a model with full physics to check for accuracy - its just not practical to use the full physics in a model run. It is also being improved all the time. Either way, even the early Hansen models were way better guide to what the future held just hand-waving about empirical guesses. Of course, there may still be unmodelled physics which is going to save us all - but would you want to bet on such possibility? What the models show, is that with the best physics available to us, our continued emissions of GHGs is going to heat the earth rapidly and we ignore that physics at our peril. -
yocta at 09:16 AM on 16 April 2010Volcanoes emit more CO2 than humans
FYI the Icelandic volcano under the Eyjafjallajokull glacier, although still erupting has been clasified as quite low on the Volcanic Explosivity Index compared to Mt Pinatubo which rated a 6 on the 1 to 8 scale. -
Doug Bostrom at 09:04 AM on 16 April 2010Are we too stupid?
Shawnhet, the absolute price per KW of generation capacity does not vary according to who pays for it. How about if we pay for subsidies of better generation technology via revenues generated by a carbon tax? A subsidy is after all the output end of a tax, yes? Saying bye-bye to our hydrocarbon slaves is going to cost money, money we can actually see as opposed to the hidden cost of C02 emissions, a sum we're borrowing and simultaneously pretending does not exist. Call it a mitigation fee, a tax, a subsidy, whatever, the cost of C02 has to be brought into our accounting system or we're going to need an entirely new and different kind of "market magic" to make substantial progress with updating our generation systems, the kind of magic that comes from the end of a wand and suffers from lack of existence. -
Philippe Chantreau at 09:02 AM on 16 April 2010Earth's five mass extinction events
There is new research suggesting that the major factor in the Cretaceous extinction was the Chixculub impact, not the Deccan volcanoes. I'm trying to find the Science article mentioned here: LINK
I recall reading that bolide impacts could also be triggers for the kind of activity that left behind the Dekkan Traps and Siberian Traps, but can't find the reference at the moment. In any case, things must be considered in context. The pressure of Human activity and the size of the population alone are enough to drive numerous species to extinction. Rapid environmental changes happening at the same time won't help.
Moderator Response:[RH] Shortened url.
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Doug Bostrom at 08:48 AM on 16 April 2010Models are unreliable
It's well worth tracking this matter of clouds through the history of GCM development, fortunately narrated pretty comprehensively by Weart. Mucho references to follow, if you're inclined. -
shawnhet at 08:42 AM on 16 April 2010Are we too stupid?
Doug, you seem to think that nuclear power can only be funded privately, in which case you might be right about them being more expensive. However, my point was that rather than spending untold amount of effort to try and make carbon forms of energy more expensive, we can just get our governments to build them directly or to make them profitable through subsidy. This will be **way** easier than what you advocate IMO. Do you think it would be easier to make your neighbor pay for flooding your yard with waste or to pay for a (government funded) common sewer system? Isn't that very ease of application the fundamental reason why sewer systems are common and the "correct" pricing of waste is not? If someone based their whole approach to dealing with waste based on forcing people to correctly price it, wouldn't we say that they were ignoring a much simpler and more effective solution? Regardless of whether PV "should" be more economical now, it will especially if research is funded on it) become much more economical in the future, at some point making more economic sense even than untaxed carbon energy. This is what makes it a pretty good investment *even if there is no government assistance for them*. Cheers, :) -
pdt at 08:06 AM on 16 April 2010Models are unreliable
I understand the idea of modeling at that level and have done things like that myself in my professional life. The issue isn't that you will get something utterly unphysical when parameterizations are used outside the fitted range (though that can happen with a poorly formulated model), but that the accuracy may be lower for predictions than for the fit. For example, if a climate model is parameterized by fitting to measured climate data, then those parameterizations are used to predict climate in conditions that do not include the same levels or rates of changes of variables (e.g. CO2 concentrations), then there is very likely greater uncertainty in the predictions than the errors between the model and the actual climate in the fitted range. -
cbrock at 05:20 AM on 16 April 2010Earth's five mass extinction events
#14 HumanityRules The phrase "the extinction holocaust" is not a direct quote from the scientist, so you might want to reconsider whether this really represents a scientist "peddling catastrophes". But let's stick to the scientific topic at hand, shall we? -
johnd at 05:01 AM on 16 April 2010Flowers blooming earlier now than any time in last 250 years
michael sweet at 02:53 AM. With regards to the tree crops you mentioned, apples in particular. It may be of interest as well as relevant, that apples were introduced into Indonesia by the Dutch more than a century ago, and not only have they adapted to the conditions there, but they are flourishing with significant areas being planted and production, constantly increasing, particularly in recent decades. Indeed it has been Indonesian farmers who have devised techniques that have allowed year-round production to be achieved, all this very close to the equator. Who would have thought that, in the tropics and with climate change and all that supposedly entails? As you noted, people do need to learn more about farming, and perhaps think outside the confines of tightly held beliefs. -
Doug Bostrom at 04:14 AM on 16 April 2010Earth's five mass extinction events
Full text of Veron 2008 here: Mass extinctions and ocean acidification: biological constraints on geological dilemmas -
Doug Bostrom at 04:10 AM on 16 April 2010Earth's five mass extinction events
A few quibbles, Thingadonta. It's not John Cook who's inferred the possibility of an acidification-related extinction but Veron. So you can take John off your list of physicists making predictions later found wrong. In any case a collection of mostly dead persons are irrelevant to this particular paper. The fact that coral population collapses may occur for reasons other than those Veron surmises says little about his hypothesis. I can think of analogies and so can you, but suffice it say that one failure mode does not exclude another. With reference to past events you say "C02 change is slow", but the change we're concerned with here and now is swift and this is the particul. I committed the sin of failing to drill through John's synopsis and thus was left with a poor understanding of Veron's case. Now that I've actually scanned Veron's paper, I see he's gone through this subject with substantial attention to detail and makes a pretty thorough accounting for his hypothesis. If you've not read it, you ought to do so. Then it would be interesting to see what you say regarding the paper and its claims specifically, as opposed to remarks about typographic errors in John's post and generalizations about past personalities and events. -
Albatross at 03:48 AM on 16 April 2010Arctic Sea Ice (Part 1): Is the Arctic Sea Ice recovering? A reality check
What CBDunkerson said @42 -
Doug Bostrom at 03:46 AM on 16 April 2010Earth's five mass extinction events
Thanks, John. I need to lean a little less on your excellent synopses and drill through into the citations a bit more. -
Doug Bostrom at 03:42 AM on 16 April 2010Visual depictions of Sea Level Rise
Argus, I should have mentioned that if you follow this thread of discussion from the beginning you'll pick up a lot of information about how satellite altimetry readings are calibrated. In particular see Peter Hogarth's remarks. -
Doug Bostrom at 03:12 AM on 16 April 2010Visual depictions of Sea Level Rise
Argus, not to come off sounding all superior but the designers and operators of these satellites as well as consumers of the data they produce do actually take orbital mechanics into account. If we could wish for anything, it would be for satellites to have been in orbit 200 years ago so we had a better, longer set of data. Longer temporal satellite coverage would help to resolve the kinds of ambiguity you mention regarding regional variances in sea level, most of which are real by the way. -
michael sweet at 02:53 AM on 16 April 2010Flowers blooming earlier now than any time in last 250 years
A lot of temperate tree crops (apples, peaches, walnuts, grapes, cherries, kiwis, pears) require a certain number of cold hours in the winter or they will not flower. This article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2707005/ gives data on climate changes in California causing the failure of tree and fruit crops. It points out that for walnut trees, the orchards take many years to come into production. If the climate changes, the farmers lose their harvest. Since tree farmers have a long outlook on production, they may not invest in new orchards. As climate continues to warm, the area where these trees can be planted shrinks. This addresses two denier issues that have been raised in this thread: 1) The data is from California, not the UK. They have long term, systematic observations. This is a Global issue. 2) These trees are not able to adapt to changes that fall out of their range of chill hours, they stop production. Native trees like pecans, hickory and wild apples (here in the US) will stop producing seeds as it gets hotter and eventually die. New cultivars can be produced for a while but that is expensive, and the orchard is still at risk of future change. I would suggest that if you don't know what chill hours are for tree crops, and you think global warming will not cause any problems, you need to learn more about farming. Of course, seed crops like corn and wheat are also susceptible to climate change, but these trees are affected NOW. -
Tom Dayton at 01:23 AM on 16 April 2010Models are unreliable
pdt, a little more description of parameterization is in Timothy Chase's comment on Open Mind. Scroll down to "IV. Regarding the Nature of Modeling," and read the first two paragraphs. -
Steve L at 01:10 AM on 16 April 2010Earth's five mass extinction events
Re #23, John you're in pretty good company there! Thingadonta, this may be your best comment here ever, but I have some questions about it. First, you're suggesting that changes due to volcanism over tens of thousands of years are too slow to be compared to what's happening now? Since excess CO2 will remain in the atmosphere for a long, long time, I don't see what you're complaining about. A dramatic change over the course of centuries will not have less impact than the same amount of change over thousands of years. Second, genera taking 10 million years to recover after mass extinctions -- I suspect that you mean the diversity within genera took a while too develop after the pruning that mass extinctions did to the evolutionary tree. But that's not what reef gaps are. Reef gaps are periods of no reef building. Sure, the biodiversity is reduced, but you don't need all of the species to build a reef -- a limited complement of species should be able to do it. So apparently conditions not conducive to coraline growth (low pH) persisted. -
vancouverd at 00:31 AM on 16 April 2010Hockey stick is broken
Is it safe to say "the last few decades are the hottest in the last 500 to 2000 years"? My local skeptic threw "Vostock Ice Core data which clearly shows the Roman Era as Warmer than now" at me ... -
Alexandre at 00:24 AM on 16 April 2010Flowers blooming earlier now than any time in last 250 years
Karl_from_Wylie #75 That's reasonable. Do check data presented as facts, and try to understand the methodology. Apply the same standards when you see a denier claim, too. -
pdt at 21:32 PM on 15 April 2010Models are unreliable
Tom Dayton quoted from another source, ""Thus statistical fits to the observed data are included in the climate model formulation, but these are only used for process-level parameterisations, not for trends in time."" I'm not sure what "process-level parameterisations" means. Presumably one needs a model of cloud properties for a range of atmospheric conditions in order to predict climate trends with time. Either you get the properties from an understanding of the physics of cloud formation and their properties or you infer them from fitting to measured climate data. "Process-level parameterisations" sounds like the fitting. Again, I'm not judging it, I'm just trying to understand it. The language is just not familiar to me. My modeling experience is in a different field. -
Tony Noerpel at 21:31 PM on 15 April 2010Earth's five mass extinction events
Hi John you mean 75 million years later here since your first bullet item was the end Ordovician: "75 million years ago in the Late Devonian period, the environment that had clearly nurtured reefs for at least 13 million years turned hostile and the world plunged into the second mass extinction event." I have to agree with Michael Le Page though I too think your site is one of the best. Except for the K-T, most major and minor mass extinctions don't lend themselves to unilateral causes. This may be why they are so rare. However, anthropogenic impacts are not just CO2 or climate related. We may be having an even bigger impact on the nitrogen cycle for example so John Russell may also be correct. We may be changing too many aspects of the Earth system too fast. Tony -
CBDunkerson at 21:20 PM on 15 April 2010Arctic Sea Ice (Part 1): Is the Arctic Sea Ice recovering? A reality check
chriscanaris #40, again I point out the fallacy of your argument... sea ice extent is a proxy at two removes for sea ice volume. Data shows that the ice volume has continued to decline... therefor no 'recovery trend' exists to have this 'statistical significance' argument over. That sea ice broke up more and/or was more spread out (the two factors differentiating 'extent' from 'volume') for a few years is irrelevant to the overall state of the ice... which is still declining. -
John Russell at 21:14 PM on 15 April 2010Earth's five mass extinction events
Paulm: I think it's perhaps slightly premature to call what's happening at the moment a mass extinction event (MME), however if there are intelligent creatures around on Earth in a few million years time perhaps they'll refer to the period we're rapidly moving into as the 'AME' -- Anthropogenic Mass Extinction. Sounds a lot more serious than 'anthropogenic global warming', does it not? -
Michael Le Page at 20:55 PM on 15 April 2010Earth's five mass extinction events
For once, I have to disagree with one of your postings, John. You present a very speculative study as far more definitive than it really is. Vernon may be right about ocean acidification being the coral killer, but the case is certainly far from proven, and may never be. I think your claim that dramatic climate change always produces mass extinctions needs major qualifications added too. The PETM was a pretty dramatic temperature increase, for instance, but it led only to a very minor marine extinction extinct. More recently, there have been some dramatic climate changes with no evidence of associated extinctions - the so-called Quaternary conundrum. Other experts I've spoken to (I've been writing a related article) say this could just because no one has looked at the fossil record closely enough, but the jury is certainly still out on this issue. Otherwise, though, a great site with great content - keep up the good work! -
thingadonta at 20:53 PM on 15 April 2010Earth's five mass extinction events
You and Veron (2008) are inferring rapid C02 changes and ocean acidifications at mass extinction periods by looking at coral reef extinctions. This inference has little/no evidence to support it, other than circumstantial. Corals reef extinctions and coral reef 'absences' in the fossil record occur for other reasons than by rapid C02 changes and inferred ocean acidification. "Throughout Earth's history, there have been periods where climate changed dramatically" Wrong/selective. Most mass extinction events occurred in geological times of tens of thousands of years. This is not what is generally meant by "change dramatically". Your point 2 above should say 75 million years later, not "ago". This Later Devonian event didn’t 'turn hostile’; it was a slow process, with multiple waves, that occurred over millions of years. The Mass extinction at the end of the Permian was caused by cascading factors that occurred over several hundred thousand to a few million years, related to Siberian Traps volcanism. Most genera took about 10 Ma years to recover, the corals were not in any way special. The End Triassic mass extinction (I think it is actually Mid Triassic) was associated with Gondawana continental breakup and injection of vast rift-related volcanism in South America, Australia, South Africa and Antarctica. Most of the hard rock aggregate on the East Coast of Australia, the towering cliffs in Tasmania, South America and so on are associated with this. It was volcanic, and slow, like most mass extinctions. The End Cretaceous was associated with Deccan Traps volcanism in India (not long after it separated from Africa) and bolide impact. This is the only certain mass extinction event associated with bolide impact, but volcanism played a major part as well (a one two punch). “The fossil record shows coral extinction occurred over much longer periods." This is because it was a result of slow, gradual, volcanically active periods. They were not periods of 'quickly changing atmospheric c02'. They were periods of slow increases in volcanism. Veron is not a volcanologist. Neither was Alvarez, who rejected both the stratigraphers and the volcanologists who informed him his bolide impact theory in 1980 at the K/T boundary wasn't all that was going on at the time. Time proved the volcanologists right, and as usual, the physicists who like to dabble in earth history got it wrong eg: • Kelvin and the age of the earth early 1900s, when stratigraphers told him the earth was much older than his calculations-he wouldn’t listen ; • the geophysicists and other non-earth physicists -including Albert Einstein-who rejected plate tectonics in the 1920s-1950s - the stratigraphers told them the rocks proved the continents moved well before plate tectonics was discovered, • Alvalrez and bolide impact 1980s, and • John Cook solar physicist 2008- now inferring mass extinctions of corals were rapid and associated largely with rapid c02 changes, I suspect most volcanologists would say this is a gross oversimplification, or at worst invalid. There is little/no evidence that slow volcanic processes were associated with inferred ocean acidifications, and corresponding reef extinctions. The reefs went extinct, like most other things, because of slow sea level changes (there is good correlation betwen sea level changes and marine extinctions), changes in volcanism (producing a variety of slow effects-again a very good correlation, but importantly-generally not with C02 changes), bolide impacts (really the only one that is 'rapid'), continental break ups (eg Triassic), continental joinings (well known to reduce biodiversity as previously separate and endemic species compete with and then extinguish each other), and many other factors. C02 change is slow, doesn’t follow these other factors or most mass exticntions, and plays a relatively minor part in the history of the earth. You're selective references to the vast peer reviewed literature on mass extinctions does not give readers the full picture of the state of understanding and history of debate in this field. -
nhthinker at 20:37 PM on 15 April 2010CO2 lags temperature
http://web.mit.edu/fnl/volume/215/rizzoli_stone.html "The paucity of observations in the tropical Atlantic and Indian oceans have considerably retarded our understanding, modeling, and prediction of these coupled modes, which are extremely important not only because of their societal consequences but because it is through them that the ocean actually drives the atmosphere. These regions and coupled mechanisms should constitute a priority of observational and theoretical research. " The confidence of CO2 forcing to the levels that climate models currently predict is tenuous, at best. Indeed, the understanding is still retarded. But it is improving all the time. Can you point to a researcher that has not put out predictions that did not turn out to be serious exaggerations of actually measured impacts? -
Argus at 19:43 PM on 15 April 2010Visual depictions of Sea Level Rise
#86 The last sentence should end: - two *kilometers* per month. -
Peter Hogarth at 19:11 PM on 15 April 2010Arctic Sea Ice (Part 1): Is the Arctic Sea Ice recovering? A reality check
tobyw at 10:57 AM on 15 April, 2010 I guess in winter the re-freeze will be pretty quick, and there’s precious little sunlight to warm the temporary open water. In summer the Russian routes are increasingly ice free. However, I didn’t know this is one of the NSIDCs frequently asked questions. They say effects are minimal (no doubt about anthropogenic though!) -
Berényi Péter at 18:51 PM on 15 April 2010Earth's five mass extinction events
I have copied Figure 1 above to a carbon dioxide history reconstruction.
You can see that CO2 either changes fast or not at mass extinction events. The same is true for times of prolific reef growth. Also, reefs can happily grow with carbon dioxide levels above 2000 ppmv, sometimes.
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Argus at 18:44 PM on 15 April 2010Flowers blooming earlier now than any time in last 250 years
JMurphy #78 I wish it were easier than that, but thank you! -
Argus at 18:30 PM on 15 April 2010Visual depictions of Sea Level Rise
How is it possible that the sea level is rising in one part of the Pacific, and at the same time falling in another part? Over a 15-year period? Can anyone explain that? - I would rather believe that the measurements are faulty. Also, how can we trust satellites to measure the sea level with millimeter precision? These satellites probably lose many millimeters in altitude for each time they circle the earth (the ISS typically loses two meters per orbital period - two meters per month). -
JMurphy at 18:06 PM on 15 April 2010Flowers blooming earlier now than any time in last 250 years
Argus, right click on the red time and date next to someone's name, copy the shortcut (or left click on it and copy what's showing in the Address bar), and paste it into the Comment box. Then use the (a href="") (/a) tags - with the correct brackets, of course. -
Argus at 17:51 PM on 15 April 2010Flowers blooming earlier now than any time in last 250 years
Somewhere in the area from around comment #56 to #71, a comment must have been deleted, because the references are off by one. This could be confusing. So, if comments are deleted for reasons, numbers should be revised within the afffected area. Alternatively, some people seem to know how to reference a comment with a hyperlink. Please tell us how you do that! -
James Wight at 17:14 PM on 15 April 2010Earth's five mass extinction events
Sorry, I meant to link to this Wikipedia page. -
James Wight at 17:09 PM on 15 April 2010Earth's five mass extinction events
Re #15 response According to Wikipedia, the Devonian spanned 416 to 359 million years ago, and the main extinction event was about 364 million years ago. So where does the "75 million" come from? -
Andy Skuce at 17:01 PM on 15 April 2010Earth's five mass extinction events
@ 15 James Wight Response: Sorry, that should be "75 million years ago". Around 75 million years ago, there was a period of 13 million years when corals were thriving. Then things went horribly wrong... Yabbut that wasn't in the Devonian (which was 354-410 million years ago)... :-) -
RSVP at 16:42 PM on 15 April 2010Flowers blooming earlier now than any time in last 250 years
To Karl_from_Wylie and Et al I also thought about the fact that the UK is not the entire planet, but then had musings along the lines of doug_bostrom's comment, "we've only got one reputation per login", and abstained thinking it wasnt worth bringing up. After reading your last comment about flawed methodologies, I would add that natural selection would likely have an affect on the timing of seeds over the course of 200 years. In other words, a seed produced in the year 1800 is not the same as a seed planted in 2000, especially as affected by an urban heat island. -
Doug Bostrom at 16:23 PM on 15 April 2010Earth's five mass extinction events
Hey, John, do you have a reference on the anoxia outcome?Response: I was just quoting the Veron paper - I suggest reading through the paper, following any references and report back to let us know what you find :-) -
Paul Magnus at 15:57 PM on 15 April 2010Earth's five mass extinction events
...and the Earth will enter the sixth mass extinction. What is the definition of a MEE? It seems to me that we are entering one now. I think we should be referencing what we are seeing now not as a Climate Crisis, but as a Mass Extinction.
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