Arguments
Recent Comments
Prev 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 Next
Comments 119251 to 119300:
-
neilperth at 14:37 PM on 17 May 2010Climate Change and the Integrity of Science: a letter to Science
I was thinking the other day............If so called "climate change" is proved and it's adverse effects on us as humans are so obvious,as you imply, why are the world's politicians doing next to nothing about it ? This seems rather odd to me. The human population increase has been a threat to humans for years but again not much is done about it - likewise lack of food and disease in certain areas of the world. -
Ron Crouch at 11:19 AM on 17 May 2010Species extinctions happening before our eyes
Speaking of which: according to the latest United Nations Global Biodiversity Outlook report. Quote:"Noting that the world has failed to meet its target to achieve a significant reduction in the rate of biodiversity loss by 2010, the report stressed that with the current rate of biodiversity loss, there will be “a severe reduction of many essential services” provided by nature to human societies, as ecosystems reach their limit and shift to alternative, less productive states, “from which it may be difficult or impossible to recover.”" -
Don Gisselbeck at 11:10 AM on 17 May 2010Species extinctions happening before our eyes
Aren't humans just about the ultimate weed species? Am I being too optomistic hoping that all we are doing is fighting for the survival of civilization? -
Ron Crouch at 09:24 AM on 17 May 2010Species extinctions happening before our eyes
Migration has it's limits as well. It is well within the realm of possibility that some species will have no place to migrate to and will finally go extinct (some migrations being vertical while others follow a lateral pattern). Some species will go extinct as a result of being displaced by the migration of other species. And let's not forget the other pressures we place upon species through loss of habitat and pollution. Someday we may find ourselves on the "endangered species list". -
chris at 07:40 AM on 17 May 2010Species extinctions happening before our eyes
thefrogstar at 06:41 AM on 17 May, 2010 frogstar, there has apparently been a long standing uncertainty over whether it was the Chicxulub asteroid impact, or an earlier (or later?) impact whose crater hasn't been found (under the sea?), or whether the massive flood basalt eruptions that produced the Deccan Traps in now-India was responsible (or a major contributor; e.g. the Deccan Traps resulted in a long term stressing and the impact delivered the coup de gras). Very recent reassessment of all the data seems to point to the Chicxulub asteroid impact being the cause of the end-Cretaceous extinction that did for the dinosaurs 65 MYA (and set the stage for the wonderful world of mammals!). The Permian-Triassic extinction was 251 MYA and was a particularly brutal mass extinction. -
chris at 07:11 AM on 17 May 2010Species extinctions happening before our eyes
batsvensson at 06:24 AM on 17 May, 2010 sorry, batsvensson; I drifted into British yoof colloquialism! I meant "massive" in the sense of "large". It's not straightforward to determine extinction rates, and these are presumably always estimates (both of the natural background rate and whatever current rate one is attempting to compare). However estimates of current extinction rates put these at 10's to 100's of times the background rate. For example an assessment of amphibian extinction rates estimates this at more than 200 times the background rate. I believe the estimated extinction rates of reptiles are similarly high. M. L. McCallum (2007) Amphibian Decline or Extinction? Current Declines Dwarf Background Extinction Rate J. of Herpetology 41:483-491 -
thefrogstar at 06:41 AM on 17 May 2010Species extinctions happening before our eyes
Yes, John, my bad (#29). CO2 was there in the penultimate sentence. I shouldn't try and do science on a Saturday night. Some of the later posts re-ignite a question I've asked of geologist-friends before, but not got a satisfactory answer to. That is: Did a large meteorite (as measured by Iridium distributions) cause the mass extinction of the dinosaurs (I'm not sure if this is what is meant by the Permo-Triassic extinction)? Or was it something else? I've also read that the extinction occurred over a period of greater than a million years, which doesn't seem much related to a cataclysmic impact of either climate or meteorites. -
batsvensson at 06:24 AM on 17 May 2010Species extinctions happening before our eyes
chris at 23:47 PM on 15 May, 2010 "The reality is that species extinctions are occurring at a massively faster rate than the background extinction rates." I am curious as to what you mean when you say "massively faster rate" above. Is it massively as in mass-extinction rate or some else rate? -
chris at 04:27 AM on 17 May 2010Species extinctions happening before our eyes
my post didn't post properly (???) Here it is again... thingadonta at 15:15 PM on 16 May, 2010 Thingadonta, please read the paper and stop blustering about things unrelated. As the study states explicitly, as does the accompanying commentary and my post you responded to, the areas studied were otherwise intact habitats. So this isn't about ants in your kitchen or koalas in Sydney CBD. It's not about tearing buildings down to reintroduce koalas, nor about "socioeconomic values". And "local extinction" is nothing like "partially pregnant" which is an objectively meaningless term. If you read the paper in the context that the Earth has something like 45% of its land area still in the form of wilderness, then in areas that have rather little local human impact (and some that do) many species of lizards across the 5 continents of the world in many habitats are struggling to cope with the enhanced Spring temperatures in a warming world. In 12% of the habitats, and more so in other regions of the world, many of these lizard species have disappeared from these habitats entirely. They are locally extinct. The common factor is warming. Many animal species are in danger of extinction and many have already gone extinct [*]. Some of these are lizards. Several of the lizard species studied by Sinervo et al are on the Red List of Threatened Species, and the incremental loss from local habitats is a potential harbinger of full extinction, since that scenario has already been played out for other now extinct species. If we are going to understand the nature of contemporary extinctions, their causes and the increasing impacts of global warming then we might as well take the science seriously. ------------------------------- [*] According to this paper "In late 2007, there were 41,415 species on the International Union for Conservation of Nature Red List, of which 16,306 are threatened with extinction; 785 are already extinct." -
Tom Dayton at 01:49 AM on 17 May 2010There's no empirical evidence
John Cook, I suggest that some combination of the contents of Ned's and Riccardo's comments be incorporated in the Is Global Warming Still Happening? post, because the question they are answering arises frequently, and the answer is not intuitively obvious. -
Riccardo at 00:47 AM on 17 May 2010It's not bad
coloursoflife, do you really think that the behaviour during vacations is an appropiate indicator of the overall benefit of a climate over another? I could agree only if you let me stay on paid vacation 365 days a year :) -
Riccardo at 00:37 AM on 17 May 2010There's no empirical evidence
PaulK, a constantly decreasing OLR correspond to a runaway warming. Luckly this is not the case. The behaviour depends on how fast OLR decreases in the CO2 bands with respect to the increase in the thermal background (proportional to T^4). If CO2 concentration increases at a "pathological" high rate you have a countinuous dcrease of the OLR; this is a runaway warming. If you have, at the other extreme, very slow CO2 increases you get a steady state slightly lower than (almost at) the equilibrium value. In the actual case, you have that CO2 concentration started increasing but the increase of the thermal emission is delayed by it's characteristic response time; so initially OLR decreases but sooner or later thermal emission will try to keep up, untill eventually steady state (not equilibrium) is reached at a value, again, lower than equilibrium. The deviation from equilibrium indicates the rate of increase of the CO2 forcing. In the so called zero dimension aproximation of the atmosphere/surface system this behaviour can be easily modeled. It's worth a try. -
Tom Dayton at 23:49 PM on 16 May 2010Species extinctions happening before our eyes
Argus, the scientists chose a sample of sites spanning a range of typical temperatures, and chose multiple sites at each of those typical temperature levels. They inventoried lizards of all species at all those sites. In other words, the scientists were indeed looking for new populations forming elsewhere. As John's post says, "What is being observed is species are relocating to cooler regions in response to warming temperatures. Lizard populations from lower elevations are expanding up to cooler, higher habitats. This appears to be exacerbating extinction of species already living in higher elevations." That means the scientists observed (those are the "facts" you are looking for) new populations in the cooler sites. In other words, the scientists did look for, observe, and report that new populations formed. But each new population competes with the extant population, helping to drive the extant population to extinction. That domino process peters out at the coolest end of the habitat range, where the extant populations tend to just disappear instead of migrate. That's because a habitable zone for lizards must have more than the right temperature. Other animals, and plants, do not migrate at the same pace, and in many cases never do. Cooler sites also tend to be higher altitude sites, entailing a whole lot of differences other than temperature (humidity, precipitation, soil composition, ultraviolet radiation, temperature extremes, predators, prey, ...). Meanwhile, back at the hottest end of the site range, there are few populations moving in, because there aren't any sites for them to come from. One of the authors of this lizard study was a guest on the Science Friday radio show on the U.S.'s National Public Radio on May 14. You can listen for free, and see pictures and other material, at http://www.sciencefriday.com/program/archives/201005141. -
neilrieck at 22:53 PM on 16 May 2010Species extinctions happening before our eyes
I just stumbled onto this article and chart which relate "CO2 to Mass Extinctions" over the past 600 million years. www.countercurrents.org/glikson220210.htm The data is attributed to geologist Peter Ward's book "Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future" -
johnd at 22:03 PM on 16 May 2010Species extinctions happening before our eyes
quokka at 19:34 PM, I was asking if there was any validity in the statement animals are not able to evolve or migrate quickly enough to adapt. If fauna can evolve into flora in nature as quickly as it seems to have from my post to yours, then it suggest that there is no validity in the original statement. ;-) -
quokka at 19:34 PM on 16 May 2010Species extinctions happening before our eyes
#30 johnd There are any number of reasons why your rosy picture is all wrong. Australia has quite a diverse flora. Some of the reasons include variety of climatic conditions and variety of soil types. The Sydney area for example has a considerable variety of plants adapted to soils over a sandstone base. These populations cannot necessarily pick up their roots and move a few hundred km south if things get a bit toasty for them. And no doubt some of the species of insect that depend on/and are depended on by those plants cannot set sail for more amenable climates without those plants. Rain forests in SE Queensland grow on soils on a basalt base. I've seen a couple of places where the transition from rain forest to dry sclerophyll is so abrupt that you would swear that somebody had built a fence. It's the edge of the old lava flows. Again, relocation for better climate may not be an option. The point is that ecology is complex, far more complex than making rather unjustified inferences from the fact that rabbits and foxes overran Australia. There will always be some species that are as tough as old nails and will survive "anywhere", even in conditions of extreme loss of biodiversity. -
Argus at 19:15 PM on 16 May 2010Species extinctions happening before our eyes
Tom Dayton (#20): Thank you very much, but I have read the 4th paragraph, and it did not answer my question ('how many new local lizard populations have appeared...'). It suggests there are difficulties with migration, but no facts are presented. I am not convinced that they bothered to look for any new populations. On the contrary, the abstract (in the given link) only states they have studied 200 existing sites (in order to see what happened with them). The purpose of the study is to show that local populations go extinct, not to look for new ones forming elsewhere. -
Riccardo at 19:09 PM on 16 May 2010Climate sensitivity is low
PaulK, even assuming that the comparison with climate models is appropiate, my point still stands. One cannot judge the sensitivy just looking at the first part of it, let alone deduce the long term behaviour of the climate system nor of the models. For example, what if the models miss just a damping factor? In the short term they produce larger postive and negative variations, but they will average out. But, as pointed out in my last comment, my guess is that Spencerr will not explicitly say anything like this in the paper, it's something just for his blog. -
johnd at 18:48 PM on 16 May 2010Species extinctions happening before our eyes
re Response "It's the fast pace that is the killer - animals are not able to evolve or migrate quickly enough to adapt." What validation is there for that statement? Many animals, insects or birds are able to migrate very quickly, especially if they are considered pests which seem able to migrate at a faster pace than humans are able to track them. Pests introduced from England quickly overrun Australia even into the hotter arid regions totally different to the English climate. The biggest obstacle may be lack of suitable habitat, lost through reasons other than AGW. Native species are often threatened not because other invading species are too slow to adapt, but because they are far too fast.Response: How do we know that fast climate change leads to mass extinctions? Past history. The fossil record shows us that mass extinction events coincided with periods of dramatic climate change. For more details, follow the link in my previous response. -
PaulK at 18:41 PM on 16 May 2010There's no empirical evidence
#35 Riccardo and #49 Ned You have both argued that the issue of observed OLR increasing over the critical period of 79 to end of century (#34 Guinganbresil and #49 Ned) can be dismissed on the hand-waving basis that it is the response to increasing temperatures. However, I do not believe that this can be easily reconciled with CO2 being the primary driver of temperature increase over this period. For an idealised system the OLR perturbation response to a year-on-year geometric growth in CO2 should be a monotonic decrease in OLR upto the equilibration time and a constant (negative perturbation) value thereafter. The constant composition experiments reported in IPCC AR4 suggest an equilibration time of in excess of 80 years in all the models. The models, at least for those whose results I have seen, also get close to a radiative equilibrium in the 70s by using atmospheric aerosols as approximately equal and opposite forcings to CO2 in order to match the temperature decrease in the period 40s to 70s. Hence, if (over the critical 1979 to 1998 period) TSI variation was negligible and there were no other unaccounted forcings, then we would expect to see a decreasing trend in OLR, and not the increase apparently observed. The increase suggests some combination of (a) CO2 effects were overwhelmed by a SW effect (withdrawal of aerosols or decrease in albedo)(b) the planet was releasing stored energy from somewhere into the atmosphere. In any event, it seems to call into question that CO2 was actually the PRIMARY driver over this period. -
coloursoflife at 16:36 PM on 16 May 2010It's not bad
There is a element of presentation that tends to mislead. I will give an example. There is only one benefit listed for human health, but several detriments. This obscures the fact that in net, warming is benefit to human health. I am not saying it is good for humans, I am saying that the higher temperatures themselves are a benefit. Where do people vacation? In Greenland, or in Crimea? Clearly, the temperatures themselves are not the problem.Response: I'm open to adding more benefits - if you find peer-reviewed papers that show benefits to health from global warming, please post them and I'll add them to the list. -
thefrogstar at 16:23 PM on 16 May 2010Species extinctions happening before our eyes
I think I must have some bad copies of Microsoft-Windows or Adobe-Acrobat, because I cannot find any reference to Carbon Dioxide in this paper. Is it in the supporting information (peer reviewed or otherwise)? Alternatively, if the premise of the article is simply: "If temperatures go up a bit then lots of Lizards will die", then it fills me with admiration for all those dinosaurs who stuck it out for so long. (Not to mention all the 'Mad Dogs amd Englishmen who Go Out in the Midday Sun'). However, there is an even worse conclusion that could be drawn. Temperatures at Football World-Cup competitions have risen since 1966, and England have never won the World-Cup since. This makes sense because the English players (just like reptiles) are not well equiped to handle the heat. The prognosis is, therefore, grim. England may never win another world cup because of CO2 induced "global-warming".Response: The last two sentences of the paper are:Although global efforts to reduce CO2 may avert 2080 scenarios, 2050 projections are unlikely to be avoided; deceleration in Tmax lags atmospheric CO2 storage by decades (4). Therefore, our findings indicate that lizards have already crossed a threshold for extinctions.
Re dinosaurs, when temperatures have changed dramatically in the past, our planet has experienced mass extinctions. It's the fast pace that is the killer - animals are not able to evolve or migrate quickly enough to adapt. -
Tom Dayton at 15:36 PM on 16 May 2010Species extinctions happening before our eyes
thingadonta, please just look up the definition of "population." The ecological definition includes "...occupying a particular geographic area." "Extinction" means vanishing of a population. You can say "extinction of the population that lived in area X." To generalize that phrase to describe multiple such cases, you can say "local extinctions." Biologists have been using the term "local extinction" for a really long time, for reasons having nothing to do with AGW. They have found it useful. The fact that you, a non-biologist, do not find it useful is not relevant to the term's use by biologists. -
PaulK at 15:34 PM on 16 May 2010Climate sensitivity is low
Riccardo at 01:42 AM on 10 May, 2010 I think it is a bit dangerous for any of us to comment on a paper that has not yet been published. However, on my reading of the article published so far, it does not appear that Spencer is claiming that he can calculate the equilibrium climate sensitivity from his approach. He is comparing the observed response against the statistics FROM THE MODELS OVER THE SAME RESPONSE PERIODS, and thereby suggesting that the models are overestimating the temperature/flux reponse. From this, one can PERHAPS validly draw the conclusion that the models are overestimating the equilibrium climate sensitivity (expressed in temp/flux). It is therefore not valid (or at least not valid until we have seen the paper) to say that "nothing can be said on the overall climate sensitivity". -
thingadonta at 15:15 PM on 16 May 2010Species extinctions happening before our eyes
Sorry accidental return button typo there, Ill repeat: re#12 Chris: I have to diagree with you here. The term 'local extinction' is a terrible term. It's like partially pregnant. The correct term should be locally absent, or locally displaced, or locally 'not observed in this survey', and so on. There is therefore no connotation of whether the species use to be there or not, whether land use patterns have changed (you dont see any koalas in Sydney CBD) and it also takes the important step in placing a value on competing land use/land use changes. This is the key issue. Nobody cares if there are no koalas (locally displaced/absent, not locally extinct) in Sydney's CBD. Despite the fact the academics dont want us to 'value' a species, in reality this goes on all the time. We don't tear down all the buildings in Sydneys CBD and replace the locally absent koalas, because of purely socio economic reasons. So all species have, like it or not, a socio economic value. This is also why stopping dams simply because of a 'locally absent' fish is limited in scope (I hesitate to say plain wrong) because it doesn't place a overall value on the socio-economic benefits of the dam. Everything has a relative value, and humans chose betweeen them, all the time. Don't get me started on other things, like whether temperate forests have less 'value' because they have less biodiversity than tropical forests, or whether nature somehow favours biodiversity in any case, or whether we should reduce biodiversity in Africa and tropical rainforests to reduce disease rates and malaria, because these are off-topic. But 'local extinction' is not just a semantic issue. Most of the distorted figures on extinction rates are based on such misuses, and abuse of such terms. Academics who just say it is 'semantic', are in effect, protecting their narrow interests and the ongoing charade about extinction rates and the relative value of different species in a whole-of-land use context, with the eg lack of socio economic context in bioregional studies, and the level of overall relative declines/increases of ecosystems as a whole in a broader region in relation to other land uses (such as within the context of increasing urbanisation in Mexico), and so on. 'Locally extinct' is by definition, internally inconsistent, a self-contradiction. I thought skeptics were the ones full of inherant self contradictions and and inconsistencies(ie they haven't yet 'smoothed' out the data to make people feel more comfortable). -
Tom Dayton at 13:41 PM on 16 May 2010Species extinctions happening before our eyes
HumanityRules, if you're going to trust Wikipedia then you should at least read all of it. There is an entry for Local Extinction. -
HumanityRules at 13:22 PM on 16 May 2010Species extinctions happening before our eyes
I have to agree with thingadonta. There is no such thing as local extinction. Here's the start of Wikipedia's description of extinction. "In biology and ecology, extinction is the end of an organism or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species" Now Wiki isn't the font of all knowledge but this seems fairly accurate. It's pretty much an all or nothing thing extinction, go to the Red List and you see it used in a very specific way. They'd be looking at maybe 10 years of no sightings before a species is called extinct. This paper in many cases has had 2 people search in a locale for 4hrs before making the call. What happens if local conditions change sufficiently to allow re-introduction of the species into the area? Is this de-extinction? All that is happening is that the word losses any real scientific meaning. But why do this? There is a reason that science uses well defined terms, it gives clarity to ideas. Why abandon that? It really does seem that in this case it's to gain greater publicity for the paper. Call it range change and it might get picked up by New Scientist. Call it extinction and you get yourself an article in the NY Times. This isn't just a semantic arguement. John's headline is an example as how poor definition in the paper leads to headlines that are alarmist in the context of the work presented. I'd contest there are no "Species extinctions happening before our eyes" in context to the work presented. -
Geo Guy at 08:44 AM on 16 May 2010Climate Change and the Integrity of Science: a letter to Science
Stephen Baines # 220 ok..mea culpa ..however I sort of wanted to catch you [which I did. ] For arguments sake let’s use your numbers: SO2 = 9 tgms CO2 = 7,200 tgms = 10 million tons = 8,000 million tons Now let’s assume that when only natural sources of the two gases are considered, then acidity is not an issue because both cycles are deemed to be in equilibrium. Therefore the following discussion reflects anthropic sources for the two gases as it is those amounts that lead to increased acidity levels. Now we look at what percentage of the two gases are believed to end up in the ocean. CO2 = 50% (IPCC) SO2 = 85% (the sulphur cycle) Anthropic SO2 emissions for the most part are land based (international air travel and shipping are not included in any statistics), the locale of the sources are important as the prevailing winds tend to carry the emissions out over the oceans. This is true for Asia, India and North America and some sections of Europe/North Africa. The 8,000 million tons therefore needs to be reduced by a factor of 50% to 4,000 million tons. We then need to consider how CO2 is trapped in water. The vast majority of it (85%) is held as a gas molecule surrounds by a water molecule and does not have any impact on the acidity of the water when held this way. The remaining 15% however forms carbonic acid over a long slow process. reference We therefore have to only consider 15% of the 4,000 million tons of CO2. This number becomes 600 million tons. Now we are comparing the 250 million tons of CO2 which forms as carbonic acid in the ocean with 8.5 million tons of SO2 which ends up in the ocean. With Carbonic acid having a pH of 5.7 and Sulphuric acid having a pH of less than 1.0, we then have to take into account the relative acidities of the two solutions to really understand their true effect on ocean water. As you must know, the pH scale is not linear but logarithmic meaning the comparison between two consecutive pH levels is a magnitude of ten and between two measurements separated by a pH it is 100 and so on. Now the difference between carbonic acid with a pH of 5.7 and sulphuric acid having a pH of less than 1.0, the separation of the pH is about 4 so sulphuric acid is close to 10,000 times more acidic than carbonic acid. Under this scenario, the 8.5 million tons of SO2 identified above has the same acidity as 85,000 million tons of CO2 compared to 600 million tons of CO2. Even if we reduce the amount of SO2 that ends up in the ocean to 20%, the 10 million tons is reduced to 1.5 million tons which has the acidity equivalence of 15,000 million tons of CO2. On another note, emissions of international flights and shipping are not included in country or UN data dues to the fact those categories do not require reporting. Hence given that the bunker oil used by ships is perhaps the most polluting fuel used today and those emissions – especially the sulphur, fall directly onto the ocean. Also, remember that emissions during the 1960’s to the mid 1980’s had higher SO2 content than current emissions – the result of clean air acts and the installation of scrubbers in industrial chimneys. Hence the proportion of SO2 to CO2 from those years would likely have been higher than what is portrayed in this analysis. Given that what we see happening in the environment reflects what occurred some 20 to 40 years ago, I then pose the question to you: which gas, when emitted into the atmosphere and then dumped into the ocean will have the greatest impact on ocean acidity? With regards to asphyxiation by CO2, I never suggested such would happen. What I did mention was volcanists working around dormant or active volcanoes are aware of the dangers of CO2 concentrating in depressions. The term sedimentation rate for gases is totally acceptable and is used to asses the rate at which CO2 settles down to the surface of the earth. CO2 is heavier than air and even in the molecular stage will settle rather than rise. Winds will carry it into the upper atmosphere and perhaps there are some other methods by which is rises, however when we are talking ground generated anthropic CO2, a good portion of it settles down to the surface. Perhaps I can use another example – CO detectors are installed at eye level compared with smoke detectors which should be placed near your ceilings. The reason for this is CO is heavier than air and settles down when a fire is smouldering or when combustion in a furnace or fireplace is incomplete. CO2 is heavier than CO hence one would expect the same pattern when CO2 is generated. My comments regarding acid rain were taken out of context by you. It is well documented that SO2 is given off both naturally and artificially and that yes as the acid seeps through grounds and rocks chemical reactions do take place. With regards to weathering, there are two environments to consider – oxidation (above the water table) and reduction (below the water table.). Sulphuric acid can be formed in both environments. The key point to understand is the locale of the sources of acid rain (on the east coast in both Canada and the US), the prevailing wind direction (west to east) is that significant amounts of acid rain have likely been deposited directly into the ocean from these sources. With regards to atmospheric contribution by CO2, again you took my comments out of context. The earth requires CO2 as an essential part of its ability to control climate. We get CO2 from a lot of natural sources, one of which is volcanic activity which ejects large amounts of CO2 into the upper atmosphere. With the high winds located there, that CO2 likely remains there for a long time (as opposed to the CO2 in my breath which comparatively has a shorter time in the atmosphere. One aspect of our atmosphere that seems to be too readily rejected by many is the role jet aircraft has in adding to the CO2 in our atmosphere. Yes I know many have said the amounts are too small to be considered and given the total numbers we are dealing with. Having said that, the growth curve for CO2 in the atmosphere as exhibited by the well known plot from the Mauna Lea Observatory, shows a remarkable increase starting in mid to late 1950’s. Coincidently, the rise in global SO2 emissions follows a similar pattern. Now if we look back to the 50’s the only part of the industrial world that really started to grow was commercial jet flights. Jet aircraft are believed to emit substantially more greenhouse gases than propeller driven aircraft. Jets also fly substantially higher than propeller aircraft so their emissions are spread via the high winds that are present at altitudes of 20,000 to 40,000 feet. Finally according to the UN, emission data for international flights are not known as fuel for those activities do not have to be reported. Hence they are not reflective in the numbers used to describe aircraft contribution to greenhouse gas accumulation. Recently a news article reported that an average trans-Atlantic flight had the same emissions as a car has over a fifty year period. This translates into the same emissions as 18,250 cars in a day. If the average flight is 5 hours, then that jet produces the same emissions as 87,600 cars during the time of the flight. When you multiply this number by the number of daily flights lasting 5 hours, then the significance of these emissions is more apparent. Complicating the issue is the fact about 80% of these pollutant are emitted at high elevations, well above the influence of most clouds and where wind then disperse them in the atmosphere.Moderator Response: Further comments on how well mixed CO2 is, will be deleted from this thread. Please post them on CO2 Measurements are Suspect. Further comments on ocean acidification will be deleted from this thread. Please post them on Ocean Acidification Isn’t Going to Happen. It is fine to post comments on this thread, pointing to your new comments on those other threads. And fine to introduce your comments on those other threads, with links to your comments on this thread. -
Ogemaniac at 08:39 AM on 16 May 2010Vote for Climate Denial Crock of the Week at Brighter Planet
I used to live in the same town as Peter, and have met him or heard him speak a few times. He is a great guy. Please give him your support. -
Steven Sullivan at 08:00 AM on 16 May 2010Species extinctions happening before our eyes
I'm pretty sure even paleontologists refer to classes of organisms having 'gone extinct' in certain areas but not others when the record shows they were once more widespread (e.g., marsupials almost everywhere except Australasia). -
dhogaza at 06:55 AM on 16 May 2010Species extinctions happening before our eyes
Here's an analogy that might get me banned. But I can't resist the terrible ethics suggested by the "extinction-is-natural" crowd.
It doesn't offend me, but I don't think it's a particularly helpful analogy. How about this: People die all the time, so as Randy Newman sang many years ago, "let's drop the big one, and see what happens ..." I mean ... it's only a rate-of-death difference, right? Nuclear holocaust vs. the background rate of death. Just as we're talking about a rate-of-extinction difference. No biggy. People are going to die anyway. Some will live, others will be born. Your preceeding post was a very good summary of the biology-based position. And quokka's got it exactly right when he says:A couple of comments on this thread do a bit of hand waving about "natural selection", the analogy of "it's all cyclical" in AGW denial...
-
Steve L at 02:49 AM on 16 May 2010Species extinctions happening before our eyes
Here's an analogy that might get me banned. But I can't resist the terrible ethics suggested by the "extinction-is-natural" crowd. Here goes: The neighbour's daughter comes seeking refuge because her dad is very drunk, and when he gets very drunk, he rapes and beats her. She is offered protection against her dad by a sober host, but this host then rapes her. At trial the host uses, "She was getting raped and beaten anyway, at least I didn't beat her" as a defense. Okay, that's pretty bad. I hope everyone agrees. But in the case of anthropogenic extinction that is being defended, she is getting raped AND beaten by the host, and this is happening at least 10x more frequently. I'm sorry if this is too offensive. Feel free to delete. There's no science in it. -
Steve L at 02:32 AM on 16 May 2010Species extinctions happening before our eyes
"Extirpation" is a perfectly good word, except that most people don't know what it means. "Local extinction" is much more understandable. It's unfortunate that some people will shorten this to "extinction" because people are bad with details. I tend to find misuse of words to be quite annoying, like when someone confuses endemic with indigenous, but in the case of "extinction" versus "local extinction", it's not a big deal. Here's why: "Local extinction" refers to the extinction of a population. What's a population? It's a group of interbreeding individuals of the same species that is isolated from other such groups. "Extinction" refers to the loss of species. What's a species? Basically it's a population that is sufficiently isolated from other groups to be recognized with a different name. It's a fairly arbitrary line, in practice. What is lost when a species goes extinct? A genetic lineage is lost that can't be replaced by extant organisms, and biodiversity is reduced. What is lost when a population goes extinct? The same thing, but to a degree that our taxonomy won't recognize the loss. There are other ways to argue about species versus population extinction. A metapopulation argument might take the form: "loss of a population is a quantifiable step toward extinction of the others." But these arguments aren't very satisfying. What's important is that there is objective evidence that the tree of life is being trimmed back, and it won't regrow any time soon. If I were a denier, I wouldn't focus on denying the loss of biodiversity -- they're going to lose that argument (as they did with the US Endangered Species Act which now protects unofficial 'species' ['distinct population segments' and 'evolutionarily significant units']). Nope, I would focus on biofunctionality ... niche extinction (or niche extirpation, if you like). Atlantic gray whales go extinct? We can transport Pacific gray whales, and they'll do the same kind of thing. Who needs polar bears? Grizzly bears are pretty similar. It's the same tactic as arguing about species versus populations, but it sets the bar much lower. That's what I would do, if I were a denier. PS. In the sentence that #5 pointed out, John has "lead" when he should have "led". -
Tom Dayton at 01:40 AM on 16 May 2010Species extinctions happening before our eyes
Argus, read the fourth paragraph in John's post. Carefully. Then read your comment again. -
Riccardo at 01:11 AM on 16 May 2010Species extinctions happening before our eyes
Thanks John, it's what i suspected but couldn't be sure. ;) Putting aside the semantic issue and the meaning of global or local extintion, the natural rate of extinction is belived to be about 100 to 1000 lower than what we observe now and we're largely (10 to 100 times) above what may be considered a planetary boundary. Still waiting to find a 100 times speed up of speciation ... -
Argus at 00:20 AM on 16 May 2010Species extinctions happening before our eyes
I would very much like to know also how many new local lizard populations have appeared in new places in Mexico since 1975, during the same time that 12% of old local populations have gone extinct. Somehow, I have a nagging feeling that they have not bothered to to travel around counting those... It doesn't make any headlines. -
quokka at 00:01 AM on 16 May 2010Species extinctions happening before our eyes
A couple of comments on this thread do a bit of hand waving about "natural selection", the analogy of "it's all cyclical" in AGW denial, and jump to an extraordinary conclusion that there's no problem or things aren't so bad as some greenies and over zealous scientists would have us believe. Well, they are. Read the WWF Living Planet Report 2008 for the big picture. Based on research by the Zoological Society of London, it reports that the number of land vertebrates has declined 33% since 1970. It is beyond my understanding how this figure is not shocking. Even if we say, divide this figure by two, it is still shocking and manifestly unsustainable. This is just an illustrative factoid, and the whole thing should be read. That biodiversity is under very serious threat is beyond doubt. Currently it's a race to the bottom to see if climate change can overtake existing causes such as direct habitat destruction as the number one cause. -
chris at 23:47 PM on 15 May 2010Species extinctions happening before our eyes
chriscanaris at 15:42 PM on 15 May, 2010 I've never really understood that passive acceptance and intellectual rationalisation of species extinction along the lines that.....extinction has always happened; it's natural selection; extinctions lead to new species etc. etc.). It's totally divorced from extant reality, makes no distinction between magnitudes and has an underlying confusion over the nature of speciation, all of which takes it into a sort of inhuman realm. The reality is that species extinctions are occurring at a massively faster rate than the background extinction rates. This has been largely due to habitat destruction and direct extirpation in the past, but global warming is joining these as a combined insult against the natural environment. Since (i) temperatures are rising at a rate that is faster than the ability of many species to adapt, let alone evolve, and (ii) habitat fragmentation has greatly limited the possibilities for migration to compatible habitats, this situation is very likely to worsen. That's the extant reality. To intellectualize this in terms of natural selection and new evolutionary possibilities is to misunderstand the nature of evolution and especially the timescales involved, especially in relation to human timescales. Massive species extinctions during the coming two centuries (say) is not going to result in a plethora of new evolved species adapted to a warmed world. It will lead to a hugely impoverished natural environment. If we became able to stabilise the situation at some time in the future (say 200 years down the road when we will certainly have had to wean ourselves of fossil fuels), the recovery of the natural environment will occur on timescales of thousands to 100's of thousands of years. However intellectually pleasing it might be to consider that interesting long term future, it lacks a human dimension. So I doubt future populations will be so keen on the environmental legacy that the sort of blase acceptance your posts describe would lead to. Personally, I don't think things will develop to such dismal state. -
Riccardo at 23:33 PM on 15 May 2010Species extinctions happening before our eyes
It's diffult to me to understand the point of local vs global extintion. Afterall it seems quite obvious. For sure, if not extinct, other terms could be used; for example "disappeared" or "are not to be found", but then what? Aren't they synonyms? Should i not use extint volcano or fire until all the active volcanoes or fires disappear from the earth? English is not my mother language so maybe I'm missing this subtlety. But as far as I can tell it's quite a silly argument.Response: I think the point of the comments on local extinction/species extinction is that if we can get into a trivial debate about semantics, people will be distracted from the fact that animal species are currently being wiped out by warming temperatures all over the world. -
neilrieck at 23:19 PM on 15 May 2010Species extinctions happening before our eyes
I hadn't heard of this until yesterday (Friday May 14) when I heard a piece on NPR's program "Science Friday" www.sciencefriday.com/program/archives/201005141 Then it was covered again today on CBC's program "Quirks and Quarks" www.cbc.ca/quirks/archives/09-10/qq-2010-05-15.html Personal Comment: mammals are not naturally attracted to cold-blooded animals but if we get over that bias we quickly come to the realization that these creatures are still an indicator species (indicating that 6.9 billion people are changing the environment). So here is a question for people who are still okay with the extinction of lizards: these creatures eat a lot of insects. When one of our enemies (insects in our crops) looses their enemy (lizards), then we have lost a friend. -
J Bowers at 23:10 PM on 15 May 2010Species extinctions happening before our eyes
@ 11 thingadonta Seems to me that locally extinct is distinctly distinguishable from globally extinct. I think you may be picking up more on semantic issues given that local extinction is just another (informal) way of describing extirpation -
chris at 23:10 PM on 15 May 2010Species extinctions happening before our eyes
thingadonta at 21:02 PM on 15 May, 2010 thingadonta, light is rarely shed on a subject by ranting. Wouldn’t it help to read the paper before blasting off inappropriately? (i) “local extinction”. This is a perfectly sound and useful descriptor. The observation of the loss of a species from a particular regional habitat allows for a rational analysis of cause (habitat destruction, ecosystem imbalance, climate change, disease etc.). If causal influence(s) are identified then it’s possible to predict what is likely to happen to the same or related species in similar habitats elsewhere in response to similar perturbation. (ii) “warming-induced local extinction”. Not sure what your “blaming it on the CO2 bandwagon” refers to! In reality, Sinervo et al. analyzed populations in 200 sites in Mexico. In these otherwise intact habitats the common element of lizard species loss is a large increase in Winter Spring temperature. The temperature rise and associated local loss of lizard species maps onto the independently determined “climate surface” (i.e. warming map). This association of high Winter Spring warming with local extinction allows for a predictive model. Simply put, one can assess regional Winter Spring temperature rises throughout the world and predict regional habitats where related lizard species will be expected to struggle. This was done and existing and new records of lizard species loss throughout the 5 continents of the world were compared with the predictions. The match is strong. In other words throughout the entire world, global warming, especially enhanced Winter Spring warming is causing the loss of lizard populations. (iii) local re global extinction. Several lizard species are already extinct (globally) during the last 100 years. This may not be due solely or even predominantly to global warming (I’m not an expert in this subject!). However it is obvious that extinctions are generally not “on-off” “here today, gone tomorrow” events (outwith bolide impacts, and mass slaughter; e.g. the final passenger pigeon populations already denuded by habitat loss). Global extinctions, especially under the influence of progressive environmental insult (global warming; habitat fragmentation and destruction) are very likely to be observed locally in advance of progressive spread to other habitats as the environmental impact (global warming in this case) advances. And of course in an increasing number of cases global and local extinctions are synonomous since many species are only defined by a local population – this is increasingly the case as a result of habitat fragmentation. -
John Mason at 22:04 PM on 15 May 2010Vote for Climate Denial Crock of the Week at Brighter Planet
Given Pete my votes! He does a brilliant job! -
thingadonta at 21:02 PM on 15 May 2010Species extinctions happening before our eyes
One should never use the term 'local extinction' in any form or context. It is an oxymoron. The day that some over-zealous academic biologists took up the term was a step backward in science and the public understanding of it. If something is only 'locally exctinct', then it is not extinct, by definition. The use of the term should be banned from all biological literature becuase it creates so much distortion and exageration. I have repeatedly come scross this problem in policy circles when various pro-green advocates want to make and enforce various policies based on something that is by definition, not only ambiguous, but variable both in time and space. Without the time and space context, the data gets distorted, misapplied, and misused. Not only does the use of such a term ensure a whole bunch of out of touch academics (whose main job function seems to be to jump on every minutely possible thinly justified exageration of ambiguities), create all sorts of useless exagerations and distortions, but broader society then also suffers from the misuse and abuse surrounding the term. And once the term gets recycyled in various models etc in the fabulous peer reviewed literature system, all hope of anything approaching normality and reality is lost. Ants are locally extinct in my kitchen every day, until the next day, as well as cockroaches, mosquitoes etc etc. The peer reviewed literature is riddled with this sort of nonsense, so many species have been catergorised as threatened, endangered, 'extinct', locally extinct, partially informally locally exctinct, (like informally partially pregnant), and so on, based on oxymorons and such like, that all resemblance to reality has been lost in the confusion. Time and spatial context of both species and broader ecosystem factors has to be applied to any discussion of species decline, but it usually isnt. Populations are dynamic, they decline and increase, they merge and split, but they don't go 'locally extinct', ever, not even once. The same goes for the Mexican paper on lizards. No only does it ignore the issue of local decline, or local 'non-extinction', but it blunders further by blaming it all under the c02 bandwagon. -
HumanityRules at 20:27 PM on 15 May 2010Species extinctions happening before our eyes
"Species extinctions happening before our eyes" John is this strictly accurate? Does this paper describe extincts or range changes? I have a real issue with the liberal use of the word extinction in this paper.Response: I had a whole section distinguishing between local extinction (the dying out of a species in a region) and species extinction. I left it out to keep the post streamlined, figuring it would come up in the comments. The 12% of extinctions in Mexico refers to local extinctions. They predicted that local extinctions will reach 39% by 2080. This equates to 20% of total species extinctions. -
J Bowers at 19:32 PM on 15 May 2010Species extinctions happening before our eyes
@ #8 chriscanaris No. There is little "wilderness" left in England, but there are plenty of bulldozers. Primate tool use is fine, for example chimpanzees and termites where the termite species is not "tooled" into extinction. -
chris1204 at 19:02 PM on 15 May 2010Species extinctions happening before our eyes
J Bowers @ 7 Did no chainsaw or bulldozer ever encroach upon the lands wherein you dwell living in perfect harmony set within pristine wilderness? -
J Bowers at 18:39 PM on 15 May 2010Species extinctions happening before our eyes
chriscanaris: "However, extinctions are a reflection of natural selection without which evolution would not occur. More adaptable organisms thrive - the less adaptable decline or occupy specialised ecological niches and are hence vulnerable as conditions change." Do you include rainforest in that, and can I conclude that trees are just an inconsequential victim of the highly adapted organisms known as the chainsaw and bulldozer? -
There is no consensus
Poptech @210, That link failed to address the key flaw in the Petition Project, so you could hardly call it a "complete" rebuttal. Namely, by the standards of the petition, 31000 represents about 0.3% of the targeted population, even with the most generous calculations. -
chris1204 at 17:36 PM on 15 May 2010Species extinctions happening before our eyes
doug_bostrom @ 4 Aw, shucks! ;-)
Prev 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 Next
