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Eric the Red at 02:58 AM on 22 June 2011When scientists take to the streets it’s time to listen up
dhogaza, You must have missed it. Maybe KR say it before it was deleted. -
Rob Honeycutt at 02:54 AM on 22 June 2011IPCC Report on Renewable Energy
Eric... This is already being discussed here. -
Eric the Red at 02:51 AM on 22 June 2011IPCC Report on Renewable Energy
Not everyone seems to think this report is accurate or even good science. http://www.marklynas.org/2011/06/new-ipcc-error-renewables-report-conclusion-was-dictated-by-greenpeace/ http://www.marklynas.org/2011/06/new-allegation-of-ipcc-renewables-report-bias/ -
KR at 02:05 AM on 22 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
Eric the Red - Tom Curtis is quite correct. The recent instrumental estimates have a larger spread, and generally lower values, but are only capable of measuring the climate change that occurs in short time periods. Therefore they have a tendency to underestimate longer term climate sensitivity. When you have multiple independent measurements (as is the case here, as various paleo measures, modellings, and recent instrumental work are using different inputs) that each produce a similar spread of uncertainties, the uncertainty is reduced with each estimate, not amplified. The median values are tightly clustered around 3ºC. Probabilities of significantly lower or significantly higher values for climate sensitivity are extremely small. So, Eric, this makes me rather curious. You've essentially asserted (repeatedly) that we are not certain, and that more study is required. The evidence says otherwise. Why should we (in a risk management sense) not act upon the data we have? Your attitude strikes me as a "Yes, but..." form of denial, and in particular of delay of action. -
Miriam O'Brien (Sou) at 01:42 AM on 22 June 2011When scientists take to the streets it’s time to listen up
Oh yes, I often witness deniers making up stuff and qualifying it with 'it's just my opinion' - or 'I seem to recall' - and never backing up the falsehood with evidence, obviously, because they can't. (I've been the target of such attacks myself for being an 'alarmist'.) It's a widely used tactic and I usually make the effort to counter it, because it's worth it even though it's tedious. (Same thing happens with gossipers - it's a tried and true technique throughout time immemorial probably, to start a rumour and then say 'no smoke without fire' - even though the gossiper was the one that made the smoke in the first place.) -
Albatross at 01:37 AM on 22 June 2011How would a Solar Grand Minimum affect global warming?
Sorry, messed up the RealClimate link. This should work. They also link to a previous paper (Wigley et al. 1990) that is consistent with their findings. If a Maunder-like minimum comes to pass it is not going to be the silver bullet that some hope for, we still urgently need to start reducing our GHG emissions. -
Tom Curtis at 01:22 AM on 22 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
Eric the Red @203: First, the following are the climate sensitivity studies analysed in AR4:
The triangles represent the most probable individual value on each Probability Density Function, but the important value, the median shown by a circle, is the value such that there is an equal probability that the true value will be above that point, or below it, given the evidence in the study. It is quite clear that for 11 out of 15 studies with a displayed median, the median is very close (within 0.5 degrees) of 3 degrees. Only one study, Andronova 2001, shows a median more than 1 degree from 3 degrees.
It is, therefore, quite plain that combining the evidence from these separate studies will result in a median close to 3. In fact, this can be seen graphically by the region in which the curves for the cumulative probability intersect:
The large spread of the red curves, estimates based on 20th Century data, show such estimates to be very unreliable - primarily because temperatures do not reach equilibrium which introduces an additional source of uncertainty compared to paleo studies.
Given this data from the IPCC, I would say your contention of wide divergence is refuted unless you can show such a wide divergence in more recent studies. Please not that because of the various shapes of the PDFs, giving confidence intervals does not provide us with enough information. We need to know the median values of the PDF for each estimate.
Second, I note that the marking feature of climate change deniers is that that all agree that we should take no expensive action against the threat of global warming. They may claim that the evidence is clear that there is no threat; or they may claim that the evidence is unclear and that therefore we should take no action. The former have at least the advantage that their position is rational, though it is flatly contradicted by the evidence. The later have neither the advantages of evidential support nor a rational position.
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Eric the Red at 01:13 AM on 22 June 2011How would a Solar Grand Minimum affect global warming?
Tom, KR, Albatross, The 97 / 100 thread seems to have gone dead.Response:[DB] There are no dead or closed thread posts here at Skeptical Science, just some with no current participation.
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Eric the Red at 01:11 AM on 22 June 2011How would a Solar Grand Minimum affect global warming?
The discussion on RC has linked to some earlier papers whcih described the potential for a solar minimum. http://www.schulphysik.de/klima/landscheidt/iceage.htm http://sesfoundation.org/dalton_minimum.pdf -
Utahn at 01:04 AM on 22 June 2011Australia’s contribution matters: why we can’t ignore our climate responsibilities
"The view that one country’s actions have no effect on other countries is present in all but the largest countries, " Ridiculously, even here in the USA, it's "it won't matter because of India and China"... -
Albatross at 01:00 AM on 22 June 2011Linking Extreme Weather and Global Warming
JMurphy and Tom Curtis, The Munch Re have their 2010 report available online. You can download it here. From the report: "We need look no further than this past year for evidence showing that climate change is real and continuing. The year 2010 sets the trend towards ever warmer years and an ever decreasing ice cover in the Arctic Ocean. Globally it was one of the warmest years since records began 130 years ago. The ice cover during the annual minimum in September was the third-lowest, reaching an absolute minimum for the month of June. Data collected by Munich Re also show that (after 2007) 2010 brought the second highest number of loss related weather catastrophes since 1980, when our data series began." -
Albatross at 00:58 AM on 22 June 2011Linking Extreme Weather and Global Warming
Tom @116, I have to agree with Actually Thoughtful @126. Great post, sad that its contents and message are lost on some. -
Albatross at 00:54 AM on 22 June 2011How would a Solar Grand Minimum affect global warming?
RealCimate has a post on the kerfuffel surrounding the statements made during the meeting of the Solar Physics Division. It is still not clear what Ken is trying to get at, other than perhaps to fabricate debate and muddy the waters. The post is about the ludicrous claims that the denialosphere (including some media outlets) and "skeptic" spin machine have made concerning the possibility that the sun could enter a Maunder-like minimum around 2020. It also presents the findings of research undertaken to address just such a question/scenario. Does Ken think that should the sun enter a Maunder-like minimum that we will enter a period of global cooling or another Little Ice age? If he broadly accepts the paper's findings then we are all mostly in agreement, his arguments are largely moot. If he disagrees, then he seems to be of the opinion that we are in for a period of prolonged global cooling. Or it might be something in between, in which case I look forward to his paper quantifying how much he thinks a Maunder-like minimum might affect global temperatures. Which is it? Because this bickering and pontificating and arguing in circles is getting very annoying. I might suggest Ken goes and tries to argue his points with the authors at RealClimate. -
Tom Curtis at 00:19 AM on 22 June 2011How would a Solar Grand Minimum affect global warming?
Ken Lambert @75, given that you now show every evidence of understanding the difference in uncertainty for absolute measurements of TSI and for relative TSI (ie, change of TSI with time), I am now at a complete loss to explain why you should quote the irrelevant uncertainty for absolute measurements rather than the directly relevant uncertainties for relative TSI when attempting to rebut KR #62. -
JMurphy at 00:05 AM on 22 June 2011Linking Extreme Weather and Global Warming
More information (from Oxfam) on 'extreme weather events', going back to 1980 : There is a statistically significant increase in all disasters, and this trend is driven mainly by a rising number of floods in all regions and by more storm events in Asia and the Americas. Changes in population do not fully explain the rising number of floods, nor can the trend be entirely attributed to changes in how disasters are recorded. It was not possible to directly analyse the effect of climate change on disaster trends; however, there is insufficient evidence to exclude the possibility that climate change is increasing hazards and hence trends in reported disasters. This effect is unlikely to be very large, because the magnitude of climate change over the past 20-30 years is relatively small when compared with (for example) the growth in the world’s population over that time. Trends in the number of reported natural disasters -
Bob Lacatena at 23:47 PM on 21 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
203, Eric the Red,There are clusters of values depending on the method used; models tend to yield higher values, temperature data lower, etc., resulting in several peaks within the distribution.
I don't see this statement to be at all true, and I'm afraid I must challenge its veracity. Can you back it up by listing the studies that you believe find a most likely value for climate sensitivity of less than two, versus those greater than two? This sort of anecdotal contention, which is so at odds with everything that I myself have read, requires supporting evidence. -
Bob Lacatena at 23:41 PM on 21 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
203, Eric the Red,Risk management may be fine for politicians and insurance agents, but is fruitless in scientific work.
I think that this is the biggest point of contention for me. We're not talking about cold, pure science. We're not trying to discover the double helix, or riddle out quantum theory in a purely abstract detached-search-for-knowledge sense. Your (as in you, personally) understandings and decisions are going to affect the course of civilization. This is not abstract. This is not trivial. This is, in every sense of the word, risk management. It is one thing to arrive at a logically consistent conclusion that there is no risk. It is another to irrationally and arbitrarily minimize that risk, dismissing it as inconvenient. You be the judge of where you lie in that spectrum, but the mere fact that you don't even choose to recognize it as a risk management issue speaks volumes. -
skywatcher at 23:22 PM on 21 June 2011CO2 Currently Rising Faster Than The PETM Extinction Event
Jerry #63 - excellent comment, well worth reading thoroughly. Seeing as modern civilisation could be described as 'well adapted' to current conditions, and more critically, can be described as 'tightly tied' to current conditions, in terms of the locations of global agriculture, coastal cities etc. We don't have the luxury of the camels or primates of Jerry's example, where we can simply migrate ourselves and all our infrastructure and agricultural zones to somewhere more pleasant. Regrettably maybe we're more like the plesiodapids, except that perhaps we can do something about the CO2 emissions? -
Ken Lambert at 23:20 PM on 21 June 2011Australia’s contribution matters: why we can’t ignore our climate responsibilities
Quoting from the works of Ross Garnaut can be fraught with exaggeration and flawed logic: "Since it is not possible for Australia to be a leader in reducing greenhouse gas emissions because others are already too far ahead, we should do our fair share in what the world needs to do. Let us look forward to a future in which Australia is doing its fair share in a global effort" Who are the leaders in reducing Greenhouse gases in the world? France? with 80% nuclear power? Certainly not the major emitters - China, USA nor Europe! China is adding 10 times Australia's total coal fired electricity capacity over the next 10 years. In 2020 China will have 28 times Australa's total coal fired capacity - so a drop of 5% in Australia's emissions will be insignificant. The USA has no plan for a carbon tax or emissions trading scheme and none will be passed in the forseeable future. That accounts for the two countries with 40+% of the planet's carbon emissions. Now I know Australia is renowned for punching above its weight - but we are completely deluded if we export carbon emissions offshore in a vain attempt to have an effect on the rest of the planet. Our main natural advantages are cheap energy from coal, efficient agriculture via energy intensive cultivation, export of natural gas etc, and digging up red dirt. Kill off these industries with a unilateral carbon tax and face a popular revolt over the sharp drop in living standards from loss of our main exports. -
jerryd at 22:53 PM on 21 June 2011CO2 Currently Rising Faster Than The PETM Extinction Event
Regarding the above points, Abundant evidence suggests that a massive input of CO2 occurred during the onset of the PETM (this could include oxidation of CH4). There were no mass extinctions (except in many benthic foraminifera). HOWEVER, There were profound changes in the environment during the event. One only has to look at the sedimentary record. The PETM now has been clearly documented in about 150 locations from around the world (McInerney and Wing, Ann. Rev. Earth Sci., 2011, nicely show most of them on a map). At almost all these locations, the PETM is marked by an anomalous horizon. The lithological changes across the PETM relate to several factors. For example, in the deep-sea (>2000 m paleo-water depth), there is typically a drop in carbonate content caused by carbonate dissolution (aka ocean acidification). In several shallow marine sections, there is a black organic-rich shale, probably caused by enhanced runoff and water column stratification. There were also numerous prominent changes in biota. Indeed, this is why there exists an epoch boundary (i.e., the Paleocene/Eocene boundary) at the start of the event! Fro example, in Wyoming, the mammal fossils found before the event are completely different than the mammal fossils after the event. We don't really think of this as a mass extinction, though, because the number of orders does not drop precipitously. Instead, it is a wholesale migration (or perhaps even origination) of animals. So "fared well" depends on what you mean. Certainly, if you were a Plesiodapid living in Wyoming, the world was not a kind place; on the other hand, if you were a camel or a primate living somewhere unknown, Wyoming suddenly became the land of bounty. In any case, Rob's main point is entirely valid. In the last 65 million years, the PETM was by the most extreme short-term event associated with rapid warming and massive carbon input. It was marked by profound environmental changes. All indications are that carbon inputs are changing significantly faster at present-day than during the PETM. This has been spun in two different ways by many people: we're heading for catastrophe; things will be okay as Earth has been through this before. I'll just stick to the facts on this point, but note that, to suggest that changes will be minimal, is not consistent with the geological record. Jerry -
Ken Lambert at 22:44 PM on 21 June 2011How would a Solar Grand Minimum affect global warming?
Tom Curtis #72 Satellites are gererally thought to have high precision but low absolute accuracy. They can give good day to day, months to month or year to year variations - but not good absolute values. If the TSI from SORCE was an accurate absolute value then Dr Trenberth's energy balance diagram would need to be adjusted. The Incoming Solar Radiation would drop from 341W/sq.m to 340W/sq.m which would require re-adjustment of the outgoing longwave and reflection terms to give a +0.9W/sq.m warming imbalance. The SORCE people had a go at this re-balance here: http://lasp.colorado.edu/sorce/instruments/tim/tim_science.htm Whatever you can make of this Tom - it had Dr Trenberth rather puzzled. -
Eric the Red at 22:42 PM on 21 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
Actually Tom, I find the opposite to be true. There are clusters of values depending on the method used; models tend to yield higher values, temperature data lower, etc., resulting in several peaks within the distribution. KR presented a nice listed of climate sensitivity studies in #188. Those that used primarily CO2 to determined climate sensitivity arrived at the highest values as the Sanderson paper had a range of 2.45 - 7.32 and Hergerl 1.5 - 6.2. Those that incorporated higher natural components arrived at much lower estimates; Schneider 1.08 - 2.3 and Harvey 1 - 2. In some of these studies the most likely value was less than 2, in other it was greater than 4. To accept a mean value at this point is unwarranted, as it has a high probability of being wrong by more than 0.5C. Risk management may be fine for politicians and insurance agents, but is fruitless in scientific work. I would advice politicians, or anyone else, to bet on any value for climate sensitivity, either high, low, or middle. -
Bern at 22:42 PM on 21 June 2011Australia’s contribution matters: why we can’t ignore our climate responsibilities
Dikran, that's a good image to use. I'll keep that in mind, next time I hear this argument. -
CBDunkerson at 21:57 PM on 21 June 2011Websites for Watching the Arctic Sea Ice Melt
Heh... was just on my way here to post that map les. Also an article on it here. The map you included above seems to show that the really thick sea ice (5 to 10 meters) which used to cover a large portion of the Arctic ocean is essentially gone (just a few scattered dots of 5 meter ice) and most of the remainder is 3 meters or less. This doesn't seem radically different from past estimates so I suspect the PIOMAS volume values have been in the right ballpark. The article above also has an interesting ice thickness graphic for Antarctica. Looks like they are going to start their data record from January 2011. They launched in April 2010, but presumably they don't want to use data from the calibration and early validation period so 1/1/11 is a good start point. They've been validating the satellite readings against plane and ground measurements and have completed that through February. Will likely continue validation for several more months before releasing satellite results without extensive cross-checking. -
Bob Lacatena at 21:42 PM on 21 June 2011Websites for Watching the Arctic Sea Ice Melt
As a side note, melt pools first appeared this year on North Pole Web Cam 1 on 6/19 about a week ahead of last year (6/25). -
les at 21:24 PM on 21 June 2011Websites for Watching the Arctic Sea Ice Melt
33,35,65... Cryosat-2 just around the corner!
I share your excitement - not least because I used to work with some of the team on envisat... evil bastards, working to become millionaris using this stuff to take over the world via the UN on the back of the scam known as AGWgreat scientists, thrilled for them. -
Norman at 20:58 PM on 21 June 2011Linking Extreme Weather and Global Warming
Tom Curtis @ 129 I did look at the third graph and went to the web site it came from. This chart does show an increase in frequency of catastropic events related to weather but I can't find supporting documentation to interpret the information. What do they mean by catostrophic, how do they define the events, what are they looking at. It looks like an insurance company put this out so is it dollar value related? If I have more information on what the graph means it could be a strong point in showing an increase in frequency of extreme events. -
Anne-Marie Blackburn at 20:55 PM on 21 June 2011Introducing the Skeptical Science team
Quality not quantity, Hoskibui ;) -
Rob Painting at 20:05 PM on 21 June 2011CO2 Currently Rising Faster Than The PETM Extinction Event
Arkadiusz - "conclusion that nature has "fared" surprisingly well during the PETM of ocean acidification and warming" Yes, but the current rate of ocean acidification is unprecedented in the last 65 million years. In fact, if the PETM carbon is from methane, acidification could be happening around 27 times faster today than during the PETM. Additionally, during the PETM ancient corals appeared to cop a bit of a hammering from bleaching events. Links for peer-reviewed papers, supporting these claims, are in the post. A global civilization did not exist during the PETM, but if it did, how do you think they would have fared given even that slow rate of change? -
Michele at 20:03 PM on 21 June 2011The Planetary Greenhouse Engine Revisited
@ Patrick Not at all, the mesosphere has to be convective as well as the troposphere. If the tropopause emits as BB the outgoing power should be σT^4= 138 W/m² and, assuming the CO2 is the sole emitting gas with a width of band of 1% of the total spectrum (we well know it is very higher), the real outgoing power should be 13.8 W/m² and this can be obtained with a δT/δz = 13.8/(2.5e-3) = 55284 K/m !!!!!!!! The same compute for the mesopause gives δT/δz = 6.8/(2.5e-3) = 2480 K/m !!!!!!!! Any other comment becomes worthless. The emitting CO2 is able to make up the convective upwelling motion and so the quasi adiabatic lapse rate with an outgoing power a little greater than (2.5e-3)10/1000 = 2.5e-5 W/m², i.e. always. The brightness temperature diagram ”(see here)” point up the fact that broadening of the CO2 band is quasi the same for the three planets having CO2 densities abysmally different. That means that the CO2 limits its action to set up the altitude from where the lapse rate starts, obtained by the balance of incoming and outgoing fluxes, and to do that are enough only a few ppm. Its effect is merely qualitative, not quantitative. -
skywatcher at 20:03 PM on 21 June 2011A visual deconstruction of a skeptic argument
What you miss is that 17GT of natural absorbtion of carbon only occurs because there is an excess of 29GT amount in the atmosphere. Without the excess human-produced carbon, absorbtion would approximately equal emission. Surely you're glad that the Earth is capable of absorbing at least half of our emissions, and thus reducing the rate our atmospheric impact by half... but sadly it's at the price of acidifying the oceans. -
Hoskibui at 19:57 PM on 21 June 2011Introducing the Skeptical Science team
I sneaked my way in with just one post (and few translations) - but yeah, great to see the faces behind the names :) -
Arkadiusz Semczyszak at 19:10 PM on 21 June 2011CO2 Currently Rising Faster Than The PETM Extinction Event
The conclusion is simple, works cited by R.P. give a very incomplete picture of the topic: what science says about PETM (despite citing the fundamental work). Among other things, Gavin Schmidt says that the changes were extremely rapid p.CO2. The second position (which I quote) is the conclusion that nature has "fared" surprisingly well during the PETM of ocean acidification and warming. -
JMurphy at 18:25 PM on 21 June 2011Linking Extreme Weather and Global Warming
Anyone wanting to look into record high and low temperatures could start at Maximiliano Herrera's site, although it might take further searching to actually find the dates for each country. However, national and continental records, with dates, can be found on one of his Wikipedia pages, showing that most of the records have been set in the last 50 years - and most of those since the 80s. -
Dikran Marsupial at 17:42 PM on 21 June 2011Australia’s contribution matters: why we can’t ignore our climate responsibilities
Whenever I hear the argument that our emissions in country X are too small compared those from country Y that there is no point doing anything about it, I always think of this demotivational poster
Which does a nice job of pointing out what a dumb argument it is. If none of us do anything, nothing will get done, and why should country Y (which usually has low per-capita emissions and lower standard of living) do anything to reduce emissions if country X (which usually has high per-capita emissions and standard of living) does nothing?
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les at 17:32 PM on 21 June 2011Who's your expert? The difference between peer review and rhetoric
28 - Chris: Regarding the changes in how publishing works etc. It's interesting to note that in HEP, ePublising started way ahead of many other disciples, for various reasons, not least of all access to cutting edge computing in the 80's. The result of that was - apart from the invention of the web - a vast increase in community based peer review. Almost ever paper published in HEP was/is issued as pre-print and widely circulated within and between labs and departments. I think folks a kind of missing a big part of the point of a/ publishing and b/peer review. An acceptable paper isn't, in any way, shape or form required to be definitively true. They are expected to advance knowledge through the introduction of new data or application of methods. Peer review is, principally, that prior art has been considered reasonably completely so that there is originality and that results which conflict with prior published work are considered satisfactorily. So, 'peers' are people who are well versed in the relevant field and would know the state of the art - or at least be able to competently check the facts as required. It's not hard. In the climate world I see two problems. First it is widely multidisciplinary. That makes it hard for someone up to their elbows in ice to know the full state of the art with sun-gazers. That's not new in academia and seems pretty well under-control. However, it is from this fact we get a lot of "it's the sun", "it's natural cycles" etc. pronouncements. The other issues is the wide range of material being hoofed around as 'new' which neither contains new methods nor new data; and which has neither originated from within a world of seminars, coffee hour chats, conferences, pre-prints and publications; let alone been subject to (narrowly speaking) peer-review. i.e. rubbish. -
Tom Curtis at 17:32 PM on 21 June 2011Linking Extreme Weather and Global Warming
Norman @120, the 2010 Chinese floods were not record breaking, but neither where they run of the mill. The displaced over 15 million people, and a 240 million people where affected by them. The problem here seems to be that you do not appreciate how global warming must impact in a chaotic system. Put simply the fact that the mean global surface temperature is 0.6 degrees warmer than it was a century ago impacts on every weather system. As the regional expression of that temperature increase is part of the initial conditions for every weather system on Earth, every weather system is a consequence of global warming. Note that this is a trivially true fact - it follows from the definition of "chaotic"; and it is also uninteresting. But not remembering it means you will hopelessly miss frame any search for the effects of global warming on extreme weather events. What is interesting is that for every weather system we currently experience, many, similar weather systems would be experienced on some other day, or some other year, or at some other hour; or possibly at the same day or hour but coming from a slightly different direction if the Earth was 0.6 degrees cooler. But they may not have occurred at the same frequency. Now it is true that for some weather systems we can look at them and see a direct reason why global warming makes them more frequent. For others, however, we can only say why global warming would make them more frequent with no hope of making any particular connection for any particular storm or flood or drought. Technically this is true even for the extraordinary events such as the Russian Heatwave, or the Brisbane floods. But it is true of all the other events as well. Therefore it is only by looking at changes of frequency that we can truly detect the signal of global warming. Because the extra 0.6 degrees is a factor in the genesis of every weather system, and because equivalent events in most cases would have happened in a cooler Earth, you don't show global warming was not a factor by saying that some other equivalent storm happened in the past. You can only show that global warming does not increase the frequency of extreme events by showing there has been no increase in the frequency of those events. Which brings us again to the third graph in my 116. Ignore the red events, which are geophysical and not impacted significantly by any plausible mechanism of global warming. (There is a slight connection between soil humidity and risk of earth quake, so I can't say no connection.) But all of the other events are events that can be impacted by global warming. Now if you ask which of them was caused by global warming, the answer is all of them. There is no other logically coherent answer. So ask instead the relevant and informative question, does the frequency of the extreme events increase with increasing temperature? The answer is plainly, yes! Not only does it increase with the overall trend in global temperatures over the period, but there is even a partial correlation with the temperature variations of individual years. -
Tom Curtis at 16:56 PM on 21 June 2011Linking Extreme Weather and Global Warming
Norman @118, the claim that humans contributed (other than by global warming) is a standard denier response to any flood. Immediately after the Brisbane floods of 2011 a skeptic of my acquaintance made that claim as a knee jerk response regarding Brisbane. In fact what humans had done to make the Brisbane floods worse was, they had built two major flood mitigation dams in the headwaters of the Brisbane river, the large of them designed to be able to safely abate 1 in 500 year floods; they had dredged the river to allow a freer flow of water; they had removed several small rocky islands, and broadened the channel at key locations for the same purpose; and they had removed the bar at the mouth of the river which in the past had acted as a natural dam to flood waters, greatly increasing flood heights in the city. But, not knowing anything about that, and not, in fact, knowing anything about the geography of Brisbane this skeptics reflex response was to immediately blame human activity. In Pakistan the situation is not so clear cut. First, in Pakistan there has been a number of major river works, including the installation of barrages to mitigate floods. On the other hand, the river had been allowed to silt up a little, and some forest hills had been heavily cleared for timber. So, human activity may or may have not been a net help, and certainly could have done more to mitigate the flood. What is certain is that these factors pale compared to the nature of the precipitation that caused the flood. When you have record breaking rainfall - in one city smashing the previous daily record by nearly 50% - the story of the flood is not how much silt was in the river. When the rain falls near the arid western frontier rather than in the typical wooded eastern mountains, the story of the flood is not deforestation. In this case the reason for the flood is very well known. It is a combination of the the blocking pattern that caused the simultaneous Russian heat wave, and record breaking sea surface temperatures in the Northern Indian Ocean. What humans did, or did not do may have influenced the depth of the flood by an inch or so - but the flood was caused by whatever caused that blocking pattern, and whatever caused the record breaking sea surface temperatures. Record breaking Sea Surface Temperatures. Global Warming. Hmmm! What possible connection could there be? -
Mike Palin at 16:33 PM on 21 June 2011Who's your expert? The difference between peer review and rhetoric
With all due credit to Churchill: peer-review is the worst form of scientific gatekeeping except all the others that have been tried.Moderator Response: [Dikran Marsupial] c.f. Newtongate ;o) -
Rob Painting at 16:24 PM on 21 June 2011What is Global Warming and the Greenhouse Effect?
Signmaster - simple answer is that CO2 is well-mixed in the atmosphere, because parcels of air rise as they are heated. Temperature gradients between warm and cool places creates wind which helps to mix CO2 in the atmosphere. Scientific explanation would cause your eyes to glaze over. As for volcanic eruptions these are localized events, and the rate of CO2 emissions can be very intense. You will note that when out-gassing finishes CO2 levels can drop rapidly as CO2 is carried away by winds/mixing. Fossil fuel combustion, by comparison, is a global phenomenon. Here's a pic of CO2 satellite measurements well above ground level:
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James Wight at 16:05 PM on 21 June 2011Australia’s contribution matters: why we can’t ignore our climate responsibilities
Australia can still be a leader. The Zero Carbon Australia 2020 Stationary Energy Plan made a convincing case that Australia can transition to a 100% renewable energy economy within ten years, by rapidly scaling up concentrating solar power technology. A follow-up report covering Australia’s transport sector is due out this year. It is an ambitious vision to transform the nation. It would stimulate the economy and get more people into the workforce. And if we lead the world in developing solar thermal technology, we will be in a position to sell it to the world, instead of scrambling to buy it from Spain at the last minute. If any country should take a leadership position, surely it is Australia. Australia is a rich nation relatively unaffected by the Great Recession. We do not have China’s problem of a rapidly exploding economy. We have an abundance of sunlight to harness. We have very high per capita emissions so we need to start earlier. We are the world’s 16th highest domestic CO2 emitter, largest exporter of coal, and soon-to-be second largest exporter of LNG. We have the world’s fourth largest proven coal reserves, 9% of the global total. Paleoclimate evidence shows that in the long term, slow positive feedbacks greatly amplify climate sensitivity, meaning the world must aim to reduce CO2 to 350 ppm to be sure of preventing dangerous anthropogenic interference. Using the cumulative emissions budget approach (which the Garnaut Review had no good reason for rejecting), even for a short-term 2°C target our global budget runs out in 20 years. That means the entire world, rich and poor, needs to be carbon-neutral by 2050 (or earlier). The richest, highest per-capita emitters like Australia need to transition the fastest to give the poorest countries more time. Australia’s per-capita share of the global budget, if you start counting now, runs out in just a few years. So Australia’s true proportionate contribution is to get to zero emissions in a decade. -
Stevo at 15:25 PM on 21 June 2011Linking Extreme Weather and Global Warming
Tom curtis @122 My apologies. I didn't read the graph correctly. That graph is exactly what I was asking for. Thankyou. -
actually thoughtful at 14:53 PM on 21 June 2011Linking Extreme Weather and Global Warming
Tom Curtis - (116) another great comment! Thank you for your contributions - I am really enjoying them. -
Tom Curtis at 14:30 PM on 21 June 2011Linking Extreme Weather and Global Warming
Norman @119:
First, the Moscow July average for 2010 was about 8 degrees C above average, not 5. It was literally off the scale for NOAA's chart. In contrast, the Siberian cold region was only 4 degrees below average (the circles do not touch, so the largest circles in that region are only the second largest on the scale).
Second, for the Moscow heatwave, 17 cells are shown with a value of 5 degrees plus; while for Siberia only two cells show a - 4 degree anomaly. Around the fringes of the Moscow heatwave are another 12 cells with a plus 4 degree anomaly, so even the fringes of that event constitute a far more significant heatwave than the Siberian cooling.
Third, as is fairly obvious, the Siberian cold snap is in fact part of the same weather pattern which caused the Moscow heat wave. Because of the anti-cyclonic pattern of NH weather systems, if one part is bringing hot air up from the south, than at a different latitude, the same weather system will be bringing colder air down from the north. Consequently whether a weather system is considered as bringing heat or cold overall should depend on the overall intensity of the system. In this case there is no question.
Finally, if just picking the Moscow heatwave and saying ergo global warming is cherry picking, which it is; then just picking the Siberian cold snap and saying ergo not global warming is also cherry picking. In 2010 there were four or five record breaking heat waves, most covering multiple nations. There were was one record breaking cold snap covering just one nation, and another very intense cold snap in part of Antarctica (and an intense heatwave in another part, though not as strong).
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dhogaza at 14:24 PM on 21 June 2011When scientists take to the streets it’s time to listen up
'Eric the Red wrote: "I have seen that happen repeatedly here."' Waiting, waiting ... particularly for an example that isn't an own goal for denialists, because we are subject to the occasional flooding of posts pointing to papers that contradict the contrarian points a poster attempts to make... Oh, wait! Maybe that's what you're trying to say! You've seen *denialists* repeatedly fail here ... -
scaddenp at 14:09 PM on 21 June 2011Linking Extreme Weather and Global Warming
"Many of the events in the graph in #116 are not cause by global warming, so a correlation is difficult." Well we can rule out the "geophysical events". However, what makes you so sure other events are not caused by global warming? Because you can assign another proximate cause without considering ultimate causes? -
scaddenp at 14:04 PM on 21 June 2011Infographic: 97 out of 100 climate experts think humans are causing global warming
Public policy in the face of incomplete data/understanding is a bet which needs to incorporate most likely and also the precautionary principle. At the moment, policy (do nothing) appears to be gambling on sensitivity less than 2 (less than 1 even), which fails in both regards. Me, I would bet on the sensitivity of the models which most accurately track temperature trend on 30 year cycle over period where we have reasonable accurate temperature and forcing data. -
signmaster at 13:59 PM on 21 June 2011What is Global Warming and the Greenhouse Effect?
I just have a question, as CO2 is heaver than air how does it get up into the higher atmosphere? When there is a volcanic eruption there is often warnings for people to keep out of the lower areas due to build up of CO2. -
Eric the Red at 13:56 PM on 21 June 2011Linking Extreme Weather and Global Warming
Norman, The Pakistani floods are nothing out of the ordinary, as they occur roughly every decade. The Russian heat wave was certainly an anomaly, shattering the previous record which stood for over 70 years. Both of these events appeared to have been caused by the same blocking pattern. Many of the events in the graph in #116 are not cause by global warming, so a correlation is difficult. Many of the nations reporting record high temperatures in 2010 do not have consistent temperature records of more than 50 years, so that a comparison with earlier periods of the 20th century is impossible. -
Tom Curtis at 13:55 PM on 21 June 2011Linking Extreme Weather and Global Warming
Stevo @117, the graph in my 116 shows an increase of between 50 and 100% in the number of extreme weather events from 1980 to 2008. That certainly seems statistically significant and over enough time to me.
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