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Tom Curtis at 02:08 AM on 11 June 2011The Critical Decade - Part 3: Implications for Emissions Reductions
One thing that perplexes me about the second diagram is the elevated end point for the 2011 start. By eye, each curve has the same area underneath it. That means each strategy uses the full permissible Carbon budget by 2050, but that in turn will mean the early start/ slower reduction approach will need to cease all remaining production instantly in 2050. Presumably a better approach would to be to have slightly higher initial reductions and to reach zero emissions some time after 2050. In that case the rate of reduction for a 2011 start will be higher than 3.7%, but still less than 5.3%. -
Tom Curtis at 01:52 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
chris @56, thank you for the link. I was not previously aware of that paper, which is interesting. Sphaerica @54, I went through the rounds on his material some time last year. Luckily for me some of it stuck. Dikran Marsupial, thanks. -
Alexandre at 01:51 AM on 11 June 2011The Critical Decade - Part 3: Implications for Emissions Reductions
Important data, in a form that is easy to communicate. Great post, Dana. -
Eric the Red at 01:46 AM on 11 June 2011Climate Consensus on a T-shirt
Tom, Detroit, I think the change from global warming to climate change just caused confusion. Using global climate disruption will add even more fuel to the fire. Out of habit, I have stuck with global warming, but see people using the terms interchangeably. As far as the shirts and mugs go, I dislike them all. Mainly because I am not a big fan of using the Doran survey. -
Bob Lacatena at 01:43 AM on 11 June 2011Climate Consensus on a T-shirt
Consider this (although maybe it still could be a little darker, or more saturated, on the lettering): -
KR at 01:36 AM on 11 June 2011Climate sensitivity is low
MajorKoko - Feedbacks are amplifications (positive) or dampenings (negative) of a forcing change. So they're related to changes in T, not T itself. That said, there are definitely phase changes (melt of clathrates, lack of summer ice in the Arctic, etc.) where feedback levels can be expected to change. As to the original statement: "basically if there is some large negative feedback which makes the sensitivity too low, it would have prevented the planet from transitioning from ice ages to interglacial periods" The Milankovitch cycle forcing change between ice age and interglacial is estimated to be on the order of 3.4 W/m^2, for a direct forcing change of ~1C. Global temperature changes for those cycles, however, are on on the order of 5-6C or so. So a short term sensitivity of ~3C for a doubling of CO2 (3.7 W/m^2) with additional long term feedbacks (ice melt, vegetative changes, CO2 temperature/solubility changes from deep ocean, etc) matches the feedback amplification seen in the ice age cycle. -
Bob Lacatena at 01:35 AM on 11 June 2011Climate Consensus on a T-shirt
I think the second is more effective because it puts the visual emphasis (many people are visual) on the relative quantities, and the words are there for clarification. The first would be okay, if the figures in the back popped more, maybe by using a lighter shade for the words (or darker shades for the bodies), or by using outlines instead of solid coloring for the words. -
chris at 01:34 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red at 21:58 PM on 10 June, 2011 Eric, remeber that Veizer himself has reinterpreted the sea surface data you cite and concludes that his temperature reconstruction now indicates a coupling to CO2 concentrations, at least throughout the Paleozoic: R. E. Came, J. M. Eiler, Ján Veizer, K. Azmy, U. Brand & C. R. Weidman (2007) Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era Nature 449, 198-201 -
Bob Lacatena at 01:32 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
52, Eric the Red, You response sounds rather dismissive, as if you want to put all of your emphasis Viezer, and see no reason to be skeptical about it. This thread is about climate sensitivity. We're discussing climate sensitivity. Viezer, Royer, Shaviv, etc. are all about climate sensitivity. So suddenly someone doesn't like the idea of discussing the topic? Is it only fun to wander off topic, and bring up things that belong on other threads? WTF... -
Bob Lacatena at 01:30 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
51, Tom, Excellent work (did it take much, or did you know this off the top of your head?), and once again you've demonstrated the need for a database which makes it easy to realize which papers, while published, were later refuted or amended in some way. It's too easy for people to find a paper that says what they want, and then put 100% stock in it (and as I said, my reading of the original paper seemed like the authors were more raising questions, and admitting to gaps in knowledge themselves, and the need for further investigation, rather then putting a stake in the ground and making specific, hard claims). -
Dikran Marsupial at 01:14 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red s/we/I/ ? ;o) -
Eric the Red at 01:10 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Tom, Thank you for the reference and subsequent graphic. I do not think we want to enter the dispute between Viezer, Royer, Shaviv, etc. -
Tom Curtis at 00:50 AM on 11 June 2011Climate Consensus on a T-shirt
detroitsylz @24, if they do, you can point out that one cold day does not a winter make. Everybody knows that a cold day, or week in a Northern Hemisphere May (or Southern Hemisphere November) does not mean that summer has been skipped this year and that Winter has come already. They know the vagaries of weather are not the same thing as the seasonal cycle, and that following that cold day, its going to get warmer, indeed much warmer before summer finally fades. So, if they are open to reason, they will also appreciate that one cold month (or year) does not end the trend of global warming. If they are not open to reason, on the other hand, they've probably heard the claim that scientists changed the name from "global warming" to "climate change" to conceal the fact that their theory had failed in the face of no warming. That, like many denier claims, is transparently false, but it means you do not get any rhetorical advantage from switching names. -
DSL at 00:49 AM on 11 June 2011Climate Consensus on a T-shirt
I like it, but it's still an argument from consensus, and worry that it will be represented as a bandwagoning attempt by doubters and denialists. I'd prefer something a little more direct. Perhaps "Your Hum-Vee is diminishing the quality of life of my grandchildren" is a little too pugnacious. Maybe a top ten list is better: FRONT Top Ten Reasons Why Global Warming is Not a Problem- God will fix everything.
- Technology will save us.
- Companies and corporations will begin to practice “ethical capitalism.”
- Gaia will bring balance back.
- More warming = more destruction = more jobs.
- The Arctic Ocean will be open for shipping.
- The physics is all wrong (that’s what this ex-meteorologist says on his blog).
- More CO2 = more plant food (I’m moving to northern Saskatchewan to grow corn).
- More CO2 = fewer coral reefs = safer surfing (yeah, baby!).
- Extreme weather events will mainly kill poor people, so poverty will end.
- Sea level rise
- Drought
- Flooding
- Water shortages
- Agricultural disruption
- Human migration
- Plant, animal, and insect extinctions and migrations
- Increased weather intensity
- Greater energy demands
- (related) A more acid ocean
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detroitstylz at 00:36 AM on 11 June 2011Climate Consensus on a T-shirt
Cool idea, and I would totally buy one if only you had used the more correct term of "climate change" instead of global warming. We should stop using the phrase "global warming" because it invites more skepticism whenever there are weather events that people point to and say "see its not getting warmer!", as I'm sure you know... -
Tom Curtis at 00:19 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red @45, Viezer et al 2000 did not allow for the change in uptake rate of O18 that results from changes in the pH of water. Royer et al 2004 correct for pH changes due to high levels of CO2, and show almost complete consistency between the temperature record and the CO2 record:A later paper by Dr Royer show that many of the apparent discrepancies are found to not be so once we find high resolution proxies for the relevant periods. He also shows that the combination of changes to solar forcing due to the "faint young sun" plus CO2 forcing correlate exceptionally well with temperatures throughout the phanerozoic:
Even the remaining discrepancies detailed in Royer 2007 have now largely been closed, as noted by Dr Alley in his famous lecture.
Moderator Response: [Dikran Marsupial] sub tags fixed -
Dikran Marsupial at 00:19 AM on 11 June 2011Of Averages & Anomalies - Part 2A. Why Surface Temperature records are more robust than we think
JMurphy An especially good point was that Prof. Jones highlighted the need for trends over longer timescales than the 16 years needed to achieve statistical sgnificance (cherry picking start and/or end dates to get the result you want invalidates the hypothesis test anyway - at least unless you account for the implicit multiple hypothesis testing). -
JMurphy at 00:14 AM on 11 June 2011Of Averages & Anomalies - Part 2A. Why Surface Temperature records are more robust than we think
With regard to CRU, it's good to see Phil Jones finally clearing-up the 'not significant' comment so (wilfully) misunderstood by the so-called skeptics : Global warming since 1995 'now significant' I'm sure we will now no longer see this 'misunderstanding' in such a prominent position all over the Denialosphere... (Oh, is that a flying pig ?) -
Tom Curtis at 00:00 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red @34, for the 20% figure:Attribution of the present‐day total greenhouse effect Gavin A. Schmidt, Reto A. Ruedy, on L. Miller, and Andy A. Lacis Received 30 March 2010; revised 27 July 2010; accepted 3 August 2010; published 16 October 2010. [1] The relative contributions of atmospheric long‐wave absorbers to the present‐day global greenhouse effect are among the most misquoted statistics in public discussions of climate change. Much of the interest in these values is however due to an implicit assumption that these contributions are directly relevant for the question of climate sensitivity. Motivated by the need for a clear reference for this issue, we review the existing literature and use the Goddard Institute for Space Studies ModelE radiation module to provide an overview of the role of each absorber at the present‐day and under doubled CO2. With a straightforward scheme for allocating overlaps, we find that water vapor is the dominant contributor (∼50% of the effect), followed by clouds (∼25%) and then CO2 with ∼20%. All other absorbers play only minor roles. In a doubled CO2 scenario, this allocation is essentially unchanged, even though the magnitude of the total greenhouse effect is significantly larger than the initial radiative forcing, underscoring the importance of feedbacks from water vapor and clouds to climate sensitivity.
(My empahsis PDF) Some indication of the climate sensitivity across a range of conditions is given by work by Pierehumbert et al (2011) from which Chris Colose shows this graph:The climate sensitivity at each point is given by the slope. In the upper section (non-snowball), climate sensitivity is never much below 3, and becomes significantly greater at higher levels of CO2. In the snowball Earth condition, climate sensitivity falls as low as 1.5 to 2 degrees per doubling of CO2. The increase in sensitivity for higher levels of CO2 is due to an increasingly powerful water vapour feedback. Chris Colose advices us to take exact numbers from these graphs with a large grain of salt, but the slopes at least are indicative. Pierrehumbert's graph is, of course, the product of a model. An evidence based approach to historical climate sensitivities can be found in Royer et al 2007. They take the fact that CO sequestration rates are controlled by temperature. Consequently, different CO2 sensitivities will result in different rates of accumulation of CO2 through out history. They model the CO2 cycle for different climate sensitivities and compare the results to the CO2 proxy record. As you can see, low climate sensitivities are inconsistent with the CO2 proxy record through out the phanerozoic, as are very high climate sensitivities.
Admittedly the evidence is tenuous due to limitations in the proxy CO2 and temperature record in the past. But the evidence we have suggests a climate sensitivity around 3 degrees as a robust feature of the Earth's history.
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CBDunkerson at 23:55 PM on 10 June 2011Websites for Watching the Arctic Sea Ice Melt
Thanks for the heads up Idunno! Fairly narrow band of predictions; 4.0 to 5.6 million km^2. Two 'public' contributions this year - one of them from Watts. -
adelady at 23:54 PM on 10 June 2011Climate Consensus on a T-shirt
Well, just to be contrary... I like the Tshirt with the big lettering, and the mug with the text and graphic separated. -
Bob Lacatena at 23:53 PM on 10 June 2011Christy Crock #6: Climate Sensitivity
47, skywatcher, Yes... I actually typed "hypothesis," and thought about it, and forget why I changed it to "theory," but you're right. On the ice sheets coming back... I think my main (natural) view is that in normal climate sensitivity time scales are utterly huge, meaning that thousands of years is a very short time frame. Human time frames of even hundreds of years, let alone ten or five, are utterly silly. So the point is that the ice sheets would grow back, and increase albedo, in their own good time, which to mother earth is more than fast enough. The same thing goes for the very slow transition in CO2 levels under normal circumstances (abrupt glacial termination being a still unresolved exception). At the same time, it puts serious emphasis on exactly how crazy we are to be doing what we're doing. The earth's climate is a machine with a few knobs and levers and dials that the pilot lovingly adjusts, only a nudge here or a smidgeon there, and still he steers the planet between pretty marked extremes. We just barged into the cockpit, grabbed the biggest lever, and shoved it all the way forward, from lowest to highest, shouting "Yeehah! Flank speed! Go, baby, go!" -
Bob Lacatena at 23:47 PM on 10 June 2011Christy Crock #6: Climate Sensitivity
45, Eric the Red, You are reading a lot (when you say "has less to do" rather than "may have less to do") into a letter which admits to and glosses over strong arguments that contradict the findings of their own work, and for which they admit there are large error bars in many areas. That said, the letter is also discussing climate 500 million years ago. I think that certainly there are some scenarios which would wildly vary climate sensitivity and the effects of certain mechanisms (in that case, CO2) then versus today's values (for instance, the lack of an extensive, land based life ecosystem 500 million years ago, to either accelerate or balance many of the chemical interchanges). The authors say as much in their conclusion when they say "climate models ... are calibrated to the present ... and may thus be unable to reproduce correctly the past climate modes". To me, this is less of a comment on climate sensitivity, and more of a comment on the fact that the actual dominant mechanisms at play could have been very different (again, on a planet 500 million years removed from this one, almost as if it were another planet in the solar system). Basically, trying to do climate work today is very hard. Trying to do it for 500 million years in the past is a daunting task, and not what I'd use as a yard stick for evaluating the quality of other science, or values of climate sensitivity. I'm not saying paleoclimate is not valuable, but 500 million years is really stretching it. You also still have not yet posted your evidence and citations for the position stated in post 34 that climate sensitivity is low. -
skywatcher at 23:37 PM on 10 June 2011Christy Crock #6: Climate Sensitivity
Sphaerica #42: a small nit - theories are the parts of science that are generally well-substantiated and tested, so presumably you meant hypotheses? I like your post at #38. I would add that there is an importance in considering the fate of the ice sheets. Regardless of the effects of presence or absence of ice on overall sensitivity (probably small but noticeable), we need to be aware of the fact that the ice sheets would not grow back as they are under present climate conditions. That is, if warming is sufficient that the ice sheets are melted, and then in the far future we are able to stabilise and manage global temperature, the ice sheets would not magically return to their present state merely by returning temperatures to those of the 19th or 20th Century. You would need to cool the climate very substantially lower than at present if you wished to lower the snow equilibrium line enough to grow the sheets back, due to the lost thickness of ice. It's part of the reason the ice sheets are at great risk from current warming, but it's not something that has a great bearing on the question of our climate sensitivity. -
MajorKoko at 23:17 PM on 10 June 2011Climate sensitivity is low
"basically if there is some large negative feedback which makes the sensitivity too low, it would have prevented the planet from transitioning from ice ages to interglacial periods" Doesn't the above assume that the negative feedback is linearly related to T? Is that a safe assumption if so? -
Mark-US at 23:12 PM on 10 June 2011Climate Consensus on a T-shirt
Whatever you do, I strongly prefer the 10x10 over the 5.882x17; especially if the goal is effective messaging to the non-committed public. IMO, I'd like to see the SS.com go to the back, which would free up space to drop the 2 grey and 1 red guys onto their own lines with an explanation ("undecided" and "skeptical"). If you aren't going to explain them, make 'em the same color (grey). Mark USA PS When can we see a shirt with Dana's awesome Observed vs IPCC CO2 graph? -
Tom Curtis at 23:06 PM on 10 June 2011Christy Crock #6: Climate Sensitivity
okatiniko @44, the Northern Hemisphere summer is warmer than the Southern Hemisphere summer despite greater insolation in the SH summer because the ocean has a much greater thermal inertia than does land. Because there is more land than water in the NH, and the reverse in the SH, it takes longer for the SH to approach the equilibrium temperature than does the NH. If insolation where held constant in a SH Summer Solstice conditions, the resulting global temperature would be significantly higher than if the same where done for the NH winter Solstice. In contrast with the seasonal variation, the temperature fluctuations between glacial and interglacial are sufficiently slow that treating temperatures as having approached equilibrium for the level of forcing is a reasonable approximation. Consequently Hansen's method of determining climate sensitivity is valid for that data, but would be invalid if applied to seasonal data where such a presumption is straight forwardly false. So far as I can tell, your entire argument against Hansen's sensitivity calculation is based on the invalid analogy between centenial and seasonal temperature variations. To the extent that is true, you have no valid criticism of Hansen. If it is not true, surely you can repost your argument without appeal to that invalid comparison as a distraction. -
Tom Curtis at 22:49 PM on 10 June 2011There's no room for a climate of denial
OK Norman, @ 46, of the top of your head list the natural disasters of 1954. And also note how many of them where record breaking and near record breaking events. The reason I ask you for the list of the top of your head is that, unless this sort of information is common knowledge, so that it can reasonably be listed "of the top of your head", then it is not relevant as to why people are deniers. If you can't list the events of the top of your head, but think there have been two years comparable to 2010 and 2011 (todate) for natural disasters, by all means discuss those years, but under a more appropriate topic. -
idunno at 22:32 PM on 10 June 2011Websites for Watching the Arctic Sea Ice Melt
Hi all, The SEARCH predictions have now been published. Follow the link @33 if interested. @37 Daniel, looking at the PIOMAS graph, between September 2006 and Sep 2007, sea ice volume fell from 10,000 cubic km to 6,000, a fall of 4,000. In September 2010, ice volume was at 4,000 cubic km. If the melt this year is at the same rate as 2007, that leaves nothing: 4,000 - 4,000 = 0 Also, I have a hunch that the Woodgate paper is part of a broader trend that exaggerates the importance of Pacific waters in Arctic melt, for the following reasons: 1. More English language research is conducted in US and Canadian waters, for obvious reasons; 2. The new sexy topic of ENSO has a huge effect on US weather patterns, but actually, with the Bering Strait being so narrow, has much less effect than the boring old Atlantic currents such as the Gulf Stream; 3. A lot of attention has been paid to 2007; but 2007 was an anomaly, which was related to a strong El Nino. I personally hold that the Arctic is being melted primarily by the influx of consistently warmer water of Atlantic origin; and I suspect that research on the Atlantic side is less well funded, often published in languages that I don't understand and, in the case of Cyrillic texts at least, subject to strong political pressure. -
MajorKoko at 22:22 PM on 10 June 2011Positive feedback means runaway warming
How do we know that the system is limited purely by the nature of its positive feedback? I'm trying to understand how the possibility of negative feedback being a limiting factor has been disregarded? There is a theory that the increasing levels of water vapour in the atmosphere due to increased temperatures might greatly increase cloud cover, increasing the earth's reflectance, reducing heat absorbtion into the system. As far as I know, the question of what the impact of increased atmospheric water vapour has on cloud formation and, therefore, albedo is still very open? So I wonder whether it isn't premature to assume that the system is self-limiting due solely to the reason given above? Particularly as the methane release issue casts further doubt on the idea that the system is self-limiting, without some other unconsidered factor coming into play. Thoughts?Moderator Response: See Water vapor is the most powerful greenhouse gas and Clouds provide negative feedback. -
Mark-US at 22:11 PM on 10 June 2011What's in a Name?
I'd like to re-visit this thread. If the "science" in question is the science of climatology, then I understand the distinction between the two terms just fine. If the "science" in question is on the human cognition side (communications, politics, psychology) then I believe the peer reviewed literature has other interesting things to say about these terms. For example, in the USA the views of those who self-identify with the democratic political party are reportedly much less affected by the choice of terms (global warming vs climate change) than those who self-identify with the republican party. See "It's All in a Name: 'Global Warming' Vs. 'Climate Change'" @ http://www.sciencedaily.com/releases/2011/03/110308173242.htm After visiting that article (or the underlying paper) please look at the end of this blog post again, where Dana discusses Luntz' memo and the concept of fear. That reminded me of other recent research comparing neurological responses of conservatives and liberals. See "Political Views Are Reflected in Brain Structure" @ http://www.sciencedaily.com/releases/2011/04/110407121337.htm I suggest that another response to "the myth" is to focus on who "they" refers to. Climate scientists have not changed the term within their purview. Social scientists did, or at least attempted to, within theirs. Those trying to perpetuate the myth are mixing apples and oranges. These studies suggest that on the social science side, there's value to talking "climate change" instead of "global warming", but of course that would come at the price of reinforcing or perpetuating the myth with respect to climatologists. Mark (USA) -
Eric the Red at 21:58 PM on 10 June 2011Christy Crock #6: Climate Sensitivity
Sphaerica, The issue of lower cliamte sensitivity in past eras has less to do with the physical properties of CO2, than in the biological and chemical reactions which increased removed of CO2 from teh atmosphere. Here is one paper that demonstrates that occurrance (note a specific climate sensitivity is not given, but can be presumed). http://mysite.science.uottawa.ca/idclark/courses/Veizer%20Nature%202001.pdf -
John Bruno at 21:33 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
Hi Rob, how about "seaweed". My point is that labeling a critical and normal component of reef ecosystems "slime" to telegraph a message of a yucky, unwanted protoplasm is not exactly helpful or scientific. And yes, a few misguided coral reef scientists subjectively refer to "slime" on reefs, but they are referring to microbes not seaweed/algae. Regarding the extreme pH values, indeed, they make up a small amount of the total measured, but are the driving force of the extant community state. Same with climate change; eg, it is the very rare extreme high values that cause coral bleaching, so it would be misleading to look at mean temp and relate that to reef state. Ill dig up the papers on the extreme values at some of the world's CO2 bubblers. -
Chris S at 20:58 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
Of interest to this topic: SAHFOS page on acidification, and paper linked therein. -
Norman at 20:57 PM on 10 June 2011There's no room for a climate of denial
DB and Albatross, Thanks for the explanation. But in the issue of denial as related to DB video, my point was that if you took all the extreme weather of a particualar year, say 1954, could you create a similar video about how extreme things are? Albatross, this thread is asking why so many doubt AGW's dire predictions. By bringing up historical data it may help to explain this. Climate scientists may be well aware of severe weather events of the past but the creator of the DB video link may not be so fully aware. -
JMurphy at 20:28 PM on 10 June 2011Climate Consensus on a T-shirt
I think the top design (10x10) looks more logical and pleasing to the eye (proportionally), and immediately presents the message graphically. Although maybe the text would be a little less bold, so that the design stands out more - but that would just be nit-picking ! It would be nice to see a design using the 10 Temperature Records, or one with the various 'hockey-sticks' - the Hockey Team ? And what about the penguin and the seedling... -
sime at 20:02 PM on 10 June 2011Climate Consensus on a T-shirt
Like the T-Shirt - I suspect these clever people would like it to, have a watch... http://www.thelancet.com/climate-change Clear concise and to the point by individuals who are qualified and have genuine experience and are therefore considered experts ergo they qualified to perform risk analysis for us. -
MA Rodger at 19:52 PM on 10 June 2011Impacts of a melting cryosphere – ice loss around the world
In the top link @#20, half the agrument put is the 5% rise in the proportion of winter-maximum multi-year ice since 2009 as per the NSIDC graphic. What the NSIDC graphic fails to show is the decline in Ice Extent over the same period. Multi-Year ice in sq km has not risen much if at all. Yes, I do rather dislike those NSIDC multi-year ice graphics. -
ScaredAmoeba at 18:40 PM on 10 June 2011Monckton Myths - a one-stop-shop for Monckton misinformation
Monckton is appearing at the Association of Mining and Exploration Companies Inc., the peak industry representative body for mineral exploration and mining companies in Australia. AMEC Convention. Perth WA 28-30 June 2011 www.amecconvention.com.au http://amec.org.au/wp-content/uploads/AMEC0031_WEB.pdf -
Riccardo at 18:01 PM on 10 June 2011Can we trust climate models?
trunkmonkey actually the term THC is less general than MOC. The latter doeas not specify one particular physical mechanism thus including wind and tidal drivers. Apart from this, they are commonly used interchangeably and even though the term "meridional" may cause some misunderstanding, as you're showing, it does not mean in any way that it includes just the atlantic latitudinal motion. But maybe we should get back on topic. -
zacharyshahan at 17:51 PM on 10 June 2011Climate Consensus on a T-shirt
bcs the visual impact, i think, is key -- & it's very easy to miss that with the top one (i did at first) -
zacharyshahan at 17:50 PM on 10 June 2011Climate Consensus on a T-shirt
i definitely vote for the bottom (original?) one! -
Rob Painting at 17:49 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
Norman @ 6 - in addition to the advice you have received above, note that the rate of CO2 increase is important to global ocean pH. In the past, increases in atmospheric CO2 have often happened over much longer timescales than is currently taking place (thousands, or tens of thousands of years vs hundreds), therefore silicate weathering, is able to buffer the extra CO2 dissolved into the oceans. The boost in alkalinity provided by silicate weathering is able to offset much of the acidification if the rise in CO2 is slow enough, because the weathering process operates on timescales of tens to hundreds of thousands of years. An additional consideration is, if the process happens slowly enough, the extra CO2 is able to be distributed to the deep ocean, offsetting the effects of acidity in surface waters. What is happening today is that humans are adding so much CO2 to the atmosphere, so fast, that the natural buffering processes, and circulation to deeper waters, cannot keep up. CO2 is building up in the surface ocean; causing pH to fall rapidly. The oceans have not been this acidic for at least 20 million years, probably much longer, and the rate of decline in ocean pH is probably unprecedented. Hope this helps. We'll have some posts touching on this within the next month. -
y-not at 17:17 PM on 10 June 2011Climate Consensus on a T-shirt
As an invisible sks supporter I recently had a T-shirt made with the "indicators of warming" graphic on it. Underneath it has the question "what are we doing?" and the sks web address. It was a one off, it is a bit busy, but hopefully is good advertising and the question forces people to think. -
ribwoods at 16:37 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
In my preceding comment, "I take that to mean that the corals that synthesize calcium carbonate (CaCO3) evolved during the last 25 million years." should have been "I take that to mean that the corals that synthesize enough calcium carbonate (CaCO3) to build reefs evolved during the last 25 million years" since the NOAA article further says, "Although all corals secrete CaCO3, not all are reef builders. Some corals, such as Fungia sp., are solitary and have single polyps that can grow as large as 25 cm in diameter. Other coral species are incapable of producing sufficient quantities of CaCO3 to form reefs." -
sailrick at 16:33 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
What about shelled zooplankton, coccolithophores? Aren't they a major carbon sink, which acidification could threaten? -
ribwoods at 16:22 PM on 10 June 2011Ocean acidification: Some Winners, Many Losers
Norman, The NOAA information page says, "Appearing as solitary forms in the fossil record more than 400 million years ago, corals are extremely ancient animals that evolved into modern reef-building forms over the last 25 million years." I take that to mean that the corals that synthesize calcium carbonate (CaCO3) evolved during the last 25 million years. Now look at the CO2 level in your graph, as of 25 million years ago. It was already lower than at any earlier time in the past 500 million years. Putting these together, it appears to me that, while solitary corals were alive during the high CO2 levels, the _modern reef-building, (CaCO3)-synthesizing_ forms did not evolve (nor have lived) during especially high CO2 conditions, according to the graph you present. -
Mike Palin at 16:00 PM on 10 June 2011Geologists and climate change denial
As a "hard rock" geologist with interests in mineral deposits (and mineral carbon sequestration), I find this meme extremely tedious. Yes, some geologists are in denial about AGW, so are some physicists, electrical engineers, doctors, etc. Get over it. Also, the notion that geologists are lacking in the basic sciences and math depends on where they have gone to university. In the US, most geology majors are required to take a year each of calculus, chemistry and physics. That is unfortunately not true here in New Zealand. -
winner at 15:50 PM on 10 June 2011Geologists and climate change denial
As long as we are all coming out :) I hold qualifications in geology and geophysics. To be honest I haven't worked in the field for a good ten years having moved back to a real life with kids and family in a big city. Anyway to cut a long story short as a former geologist I have been surprised at the number of my fellow "geologists" on the denial side of the argument. I admit when I first heard of GW I thought I had heard it all before but when I took time to read the work going on into GW I quickly came around to the consensus view. This is where I find it hard to understand why "geologists" would doubt the science. For me anyway knowing the earth's history better than most helped me better understand the difference between past events and what is occurring today. -
trunkmonkey at 15:50 PM on 10 June 2011Can we trust climate models?
Riccardo The common notion of MOC was developed in the Atlantic where the Gulf Stream was identified long ago, and slowly evolved into the concept of a large convection cell extending through both hemispheres along a meridion somewhat west of Greenwich. I think in the 1960's people began to realize that this was part of a larger thermohaline circulation, but the details were vague. When the benthic foram and ice core data came on line people noticed that when Greenland was colder during DO events, Antarctica was warmer. This led to the idea that the MOC and inded the THC were hemispheric temperature balancing mechanisms with the Geenland-Antarctic axis criical to the overall circulation. A large literature is devoted to how MOC may have been shut down or restricted during Bond events and when vast glacial lakes suddenly dumped fresh water ino the nordic sinking area. I believe that THC differs from MOC in three important ways: The Atlantic is not the most important axis and the overall circulation is driven by the Antarctic beltway. The circulation loops in the Pacific and Indian oceans move in the opposite direction from the Atlantic. The most important axis of THC is lattitudnal rather than longitudinal (meridional); that is, it serves to balance the ocean basins rather than the hemispheres. There, you see? I can be one of those math challenged arm waving geologists!
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