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johnd at 15:40 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
muoncounter at 14:28 PM, you are putting the wrong emphasis on the results. The lower yield claim is comparing the FACE trials to those expected by modeling which was based on enclosure trials. It is basically supporting this which I had posted earlier- "Numerous free air carbon enrichment field trials are providing some such data, IIRC, the existing models generally failing to reliably forecast the increased yields many such trials produce." The FACE trials all showed positive responses to the CO2 enrichment for all 3 parameters across all 3 grains. The failure is with the modeling assumptions. Those who actually read the paper will see as much indicated near the end. One of the objectives of the FACE trials was to provide real data that would allow the models to be calibrated rather than just using assumptions. I don't think you'll find the big difference between the greenhouse and the real world, that is fairly well understood by those in the industry. As you have shown, the big difference is between the assumptions being made in the modeler's office and the real world. -
Citizen99 at 15:38 PM on 8 March 2011Human CO2 is a tiny % of CO2 emissions
mikea01 - it is also inaccurate to consider the discussion in these posts as some kind of convocation of "experts" and thus judge that there is little agreement among them. In fact, my perception is that this site tends to be flooded with ramblings from inexpert ideologically motivated denialists whose purpose is to create the exact impression of non-agreement that you are reporting. In fact, it is established beyond doubt that more than 95% of real "experts" (i.e., folks who know what they are talking about) do agree that climate change resulting from the massive combustion of fossilized hydrocarbons is becoming a serious threat to our fragile modern civilization. Please take the time to read one of the excellent books on the subject written by actual experts such as Dr. James Hansen. -
johnd at 15:11 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
adrian smits at 14:18 PM, I agree also. Within agriculture, as with most fields, there is a huge pool of knowledge that has been accumulated along the way. Much of it is considered self evident amongst those who carry it. In many cases, techniques are developed without any formal scientific input, the scientists often left to produce a paper trail long after the practice had become standard procedure. -
actually thoughtful at 14:52 PM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
I am not sure we need to divert 100 billion into researching this new, 24/7 non solar, non fossil, non wind, non nuclear answer. If I could control all government spending, sure I would lower spending on say, fossil fuel subsidies or war and increase on long shot total replacements. But the answers are already here. We have a long, long, long way to run before we've begun to utilize solar, wind and wave to meet our needs, as CAmburn points out, nuclear has a role. Why wouldn't every available penny be dedicated to the tested, here-and-now solutions? That is what you would do if you thought it was a critical problem. So I don't think your point hangs together as you dismiss the technologies that are already working (solar, solar for heat, wind, wave, nuclear, etc) in the search for this new holy grail. { - snip - }Moderator Response: [DB] The referenced comment was deleted. -
muoncounter at 14:28 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
adrian s, "adding c02 to greenhouse air is standard practice" Ironic: Greenhouse gases are good for plants in greenhouses. But we're not necessarily talking about plants in greenhouses here. Here's one of those peer-reviewed thingies everybody talks about. Long et al 2008: Free-air concentration enrichment (FACE) technology has now facilitated large-scale trials of the major grain crops at elevated [CO2] under fully open-air field conditions. In those trials, elevated [CO2] enhanced yield by ~50% less than in enclosure studies. This casts serious doubt on projections that rising [CO2] will fully offset losses due to climate change. Apparently there's a big difference between conditions inside the greenhouse and the outside world. -
johnd at 14:26 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
With at least two contributors to this thread known to be real world farmers, this allows some balance to be bought to the subject which is otherwise only about theoretical models based on a few assumptions, some perhaps not even the most relevant. Theories and formulas founded on laboratory experiments ultimately have to be validated against the knowledge accumulated by such real world farmers who operate in a infinitely more variable environment than any lab can recreate. That knowledge is very often supported by reliable data going back generations covering a wide range of variable conditions in an otherwise constant environment, one that is generally very well measured for all the relevant parameters required. As has already been pointed out, there are many more important variables that have to be taken into account, if not for the projections being made, then certainly to allow the models to be calibrated against past data. Numerous free air carbon enrichment field trials are providing some such data, IIRC, the existing models generally failing to reliably forecast the increased yields many such trials produce. Most of the debate about climate change revolve around statistics, theories and formulas, and peer reviewed papers. But there is a real place in the debate for those people, those with dirt under their fingernails, who are in the unique position to be able see whether the way the climate performs in theory is how it actually manifests itself on the ground. Talking of ground, whilst agriculture depends on conditions that exist at ground level and below, virtually none of the measurements, such as temperatures, CO2 are taken from inside the growing zone. With temperatures, especially the extremes, there is generally a great difference between what is measured 1.2m above the surface and what it actually is right in the growing zone. This in understood by the scientists who work in agriculture, but I don't see anywhere where climate scientists use this different set of data.Moderator Response: For some scientific studies of the effects of CO2 and heat, see the summary by the U.S. Dept. of Agriculture, and other studies, linked in the comments of the thread "CO2 is not a pollutant." -
adrian smits at 14:18 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
Camburn is right Michael I have read similar articles.In fact adding c02 to greenhouse air is standard practice because it increases yields dramatically. -
Camburn at 14:14 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
I will state this and then have to head to bed: Each study I have read concerning co2 and plants results in a higher level of co2 being benifical for plant growth. It appears that plants must have evolved during a time when co2 levels were substantially higher than present. Their growth response to co2 is almost like a growth response to nirtrogen/phosphorous etc. People who grow food in greenhouses have known this for years and elevate the level of co2 to compensate. It is not yet practical on a commercial farm scale to do so. If it was, it would have been done. -
Camburn at 14:10 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
I did a quick google. Here is one result. As you can see, this is complicated. Unless you are a farmer and want to stay abreast of this, most won't care. There have been numerous studies done by universities in the US concerning co2 and growth/health/yeild etc. http://news.illinois.edu/news/09/0209co2.html -
Camburn at 14:05 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
Ok....I was too low. This from an article in a farm magazine. I will have to dig to find the experiments done. "•Cereal grains including rice, wheat, barley, oats and rye average between 25 and 64 percent higher yields under elevated CO2 levels." -
HumanityRules at 14:02 PM on 8 March 2011Blaming the Pacific Decadal Oscillation
I wonder if you could go into the relationship between PDO and ENSO a little more?
It appears that to a large extent PDO may just be a measurement of one of the impacts of ENSO in an appear outside of the 'tradional' ENSO region. Is this what you mean?
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michael sweet at 13:56 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
Camburn: "If memory serves me" is not a reference. Please give a link that supports your unusual claim. Peer reviewed papers are convincing. "memory" is not. -
HumanityRules at 13:56 PM on 8 March 2011Blaming the Pacific Decadal Oscillation
Riccardo, "Thus, the PDO is a response to something else; treating it as a forcing must be taken with caution." I'm not sure the point you're trying to make with this? You think that because PDO maybe a feature or related to ENSO that this undermines it's possible role in forcing climate? I can see if we knew the whole truth about PDO that would help in understanding it's role but I don't get why we should specifically treat it with caution because it is related to ENSO? -
HumanityRules at 13:43 PM on 8 March 2011Blaming the Pacific Decadal Oscillation
"The question is, then, how to reproduce Spencer's result." Did you consider e-mailling him and asking him what he did? -
Camburn at 13:31 PM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
There is an answer to building a mostly non carbon energy system. It is available, and has been tested. It is called nuclear. -
Camburn at 13:23 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
muoncounter: I agree, water vapor is by far the most powerful greenhouse gas. Everything else pales against it. What research has shown is that the plants require substantially less moisture with higher co2 levels to produce the same yield. The hope is that if moisture stays somewhat constant that yields will increase by 18-22% if memory serves me.Moderator Response: [DB] Actually, CO2 is the Star Actor (the principal control knob) on the planetary thermostat stage; water vapor plays a supporting role in warming the atmosphere. If one removes the CO2 from the atmosphere, global temperatures plunge by more than 30°C in the first 10 years alone (and the resulting increase in global ice turns the planetary albedo a whiter shade of pale):
Lacis et al 2010 -
Camburn at 13:20 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
But now we have drifted into agonomy rather than this application. -
muoncounter at 13:20 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
adrian s, "My understanding about rising c02 levels and precipitation ... the two will largely mitigate each other" Your understanding appears to be incomplete. See the thread Water vapor is the most powerful greenhouse gas, where you will find that water vapor amplifies CO2-driven warming in a process known as 'feedback.' This is the water vapor that is the precursor to what you hope for in terms of relief from rainfall. -
Camburn at 13:19 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
adrian: That is what current research shows. The higher levels of co2 result in fewer stoma which results in less transpiration. There are wild wheat grasses that have this gene that show this effect presently. Wheat and corn breeders have been trying to incorporate this gene for some years now into new hybrids. The thinking is that there should be an impressive yield response to this. -
Mike1637 at 13:17 PM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
@14. What's your point stevee? I don't think it ultimately matters if they were hacked or leaked, though hacking seems far more probable as it is known that they were downloaded from a backup server - hardly the way your average "leaker" would obtain them. In any case, none of it changes the fact that the explanation for the "hide the decline" email has not even a whiff of conspiracy about it (other than to the woefully misinformed). Nor that the "decline" is not, and never has been, a scientific secret to anyone. -
muoncounter at 13:06 PM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
daisysm, "perhaps you are missing the point." That is one way to look at it. Perhaps the points made here differ in substance from the ones you are trying to make. You might consider doing some reading on warming issues. Start with the Newcomers guide then move on to Most used skeptic arguments. "what’s the thrust of the Federal response to this dire situation? …To make electricity only when the wind blows and the sun shines" Are there no renewable electric projects funded by corporate interests? Ever hear of T. Boone Pickens? "Let’s not forget that Californians are not paying the full cost for renewable energy, thanks to massive Federal subsidies." Hardly anyone in the US pays the full cost of energy. Know about massive Federal subsidies (aka tax breaks) to the oil industry? "I wondered if the threat to humanity posed by reliance on carbon fuels was real, since Government wasn’t looking for a new, full time, 24/7 energy source" I have to admit, that's a unique point of view. Because govt isn't doing something (in your view), it isn't a real problem? How about this for a reason that govt's search for replacement fuel is so slow: There is a massively funded industry lobby against that initiative! "I still insist that the “threat to humanity” is an overblown alarmist cry." Mere insistence on something doesn't qualify as evidence, scientific or otherwise. See the threads Its not bad for some examples of what 'alarmism' is trying to say. -
adrian smits at 12:30 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
My understanding about rising c02 levels and precipitation is that the two will largely mitigate each other.If there is a reduction in rainfall that should be compensated for somewhat by crops that are more drought resistant because of higher c02 levels. -
RW1 at 12:20 PM on 8 March 2011Blaming the Pacific Decadal Oscillation
scaddenp (RE: 73), "Perhaps we should takes this "CO2 lags temperature" if wish to continue to argue that GHGs are unimportant for glacial/interglacial cycle." Yes, I'm arguing the evidence doesn't support that GHGs (i.e. CO2 levels) are a significant factor in the glacial/interglacial cycle. Do you wish to discuss this further over there?Moderator Response: Definitely not here. -
adrian smits at 12:13 PM on 8 March 2011Interactive animation of the climate change impact on agriculture
The problem with this graph is that it models local temperatures.However the models indicate almost no warming at lower latitudes with increased warming at higher latitudes where millions of acres of land will suddenly become arable because of increases in temperature.A careful study of the graph would seem to indicate a huge net gain in food production for the planet in a warming world.As a farmer I know that you need heat units to grow crops and the corn belt in north America has been moving north for years.We consider this a blessing that allows us to grow crops with higher yield and it gives us a greater choice as to what we can grow. -
Alexandre at 11:27 AM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
ClimateWatcher #15 said How about asking him about certainty of AGW when the measurements of solar, albedo, and output LW are all greater than CO2 forcing? Excuse me?
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Tom Dayton at 11:04 AM on 8 March 2011Renewables can't provide baseload power
One place where baseload power can be provided by wind, is a chain of wind turbines running along the Atlantic coast of the northern U.S. The Atlantic Wind Connection project will take advantage of wind patterns that blow sufficiently at least somewhere along that chain at all times. -
Rob Honeycutt at 11:00 AM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
stevee @ 11... Do you understand how small the CRU is? -
Rob Honeycutt at 10:57 AM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
ClimateWatcher... Trenberth meant that it's a travesty that we can't adequately track the heat energy in the climate system. We need better systems for understanding and tracking where the heat energy moves around the planet. That's very clear if you actually read his emails and his research. The "travesty" is clearly spelled out in his papers. Difference between 1997 and 2009? How about 12 additional years of intensive research. Science advances to create better understanding. In this interview he clearly says the IPCC states that the anthropogenic nature of warming is "unequivocal." He is obviously in agreement with this statement. Do you understand what he's saying about "turning around the null hypothesis?" He means it is clearly shown by the research that we are warming the planet. The evidence is overwhelming. It is up to the skeptics now to prove otherwise. -
daisym at 10:34 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
#69 dana1981: Thanks for the response to my comments @ #68. My position needs some clarification: I prefaced my comments by saying, “I think everyone is missing the point.” Your response shows me that perhaps you are missing the point. 1. I commented that we must find a NEW, full time, 24/7 energy source that could replace carbon fuels. You disagreed, saying that wind and solar (and a few other, lesser technologies) fit the bill. This isn’t factual. These are neither new, nor scalable, nor reliable sources of full time, 24/7 energy. The USA isn’t looking for such an energy source. I reiterate: Why aren’t we looking? The Federal government spent $100 billion for scientific research that blames carbon fuels as a threat to humanity. So what’s the thrust of the Federal response to this dire situation? …To make electricity only when the wind blows and the sun shines, and keep on burning carbon fuels! How will this end the threat to humanity? Why aren’t we spending another $100 billion on R&D to find a full time, 24/7 replacement for carbon energy? Wind, solar, etc. won’t do the job. You missed the point! 2. I commented that investments in energy-saving things had little economic benefit, except for the early investors. Reduced purchases of postage stamps forced the Postal Service to raise the price of stamps. Water consumption in Colorado has gone down, while consumer bills have gone up (not down). These are dynamics of the market system. If as you say, California rates have increased as per capita consumption has decreased, you and I implicitly agree on these very dynamics. Let’s not forget that Californians are not paying the full cost for renewable energy, thanks to massive Federal subsidies. Without subsidies to reduce the cost of manufacture, these rates would be much higher! 3. You also had problems with my closing comment, where I wondered if the threat to humanity posed by reliance on carbon fuels was real, since Government wasn’t looking for a new, full time, 24/7 energy source to replace carbon fuels. You claimed that the RGGI States spent 11% of their carbon funds on renewable energy. But was this for R&D to find the “holy grail” of energy sources (to replace carbon fuels)? Of course not. Not mentioned was that these same States spent 17.4% of their carbon funds to prop up their operating budgets. Given no interest at the Federal or State level to find such a replacement for carbon fuels, given interest only in reducing (not eliminating) use of carbon fuels with part time wind and solar energy, and given the proclivity to use energy revenues for non-energy purposes, I still insist that the “threat to humanity” is an overblown alarmist cry.Moderator Response: It is not necessary to have a single technology provide 24/7 energy. See "Renewables can’t provide baseload power." -
Glenn Tamblyn at 10:29 AM on 8 March 2011Interactive animation of the climate change impact on agriculture
Sphaerica's comment about precipitation is critical, and it is unclear wheter this model includes that. It is relevent that the crop that does best at high temps is rice, which is the highest water user. -
Marcus at 09:52 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
...oh, & actually thoughtful is dead right. Seems you-like most denialists-want to have your cake & eat it too. You're usually first in line to tell us that global warming isn't real-or isn't the result of burning fossil fuels (oh no, its all the fault of that relatively tiny waste heat effect). Yet here you're claiming the opposite. So which is it? -
ClimateWatcher at 09:30 AM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
This is polemic not science. How about actually asking Trenberth what he meant by the 'Travesty'? How about asking him why there is so much difference from Trenberth 97 to Trenberth 2009 energy budget? How about asking him about certainty of AGW when the measurements of solar, albedo, and output LW are all greater than CO2 forcing? These are science questions but not asked here. And "Turn around the null hypothesis?" Great advancement for science. -
Paul D at 09:27 AM on 8 March 2011Interactive animation of the climate change impact on agriculture
Generally, agriculture is an 'artificial' system that can be manipulated to a certain extent by humanity to mitigate climate change, largely by planting different crops as climate changes, or 'engineering' new varieties. A bigger problem is crop migration to the point where some areas may not be suitable any more for any agriculture. SO it isn't a case of less productivity from a crop, but elimination of some land from the agriculture 'bank'. This has nothing to do with traditional agriculture cycles and seasons, posed by Camburn. It is more to do with a complete break down of such cycles in certain areas of the world. Another big problem is the capacity of wild/natural species to adapt. People do not depend solely on agriculture, we are dependent on a wide bio-diverse environment. As that bio-diversity reduces, as one species is lost, it knocks out a whole chain of other species. Alternatively, you can get a massive destructive increase in a species if it's 'predator' is eliminated. Effectively warming is one massive hard to predict experiment, with many risks. -
actually thoughtful at 09:00 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Gilles, I have seen you make the same point on a few blogs - that our actions to reduce fuel use will only hasten the 3rd worlds use of fuel (by lowering the price, and making it affordable). And you analysis is OK, as far as it goes. Which is not far enough. Your analysis misses the key point - that fossil fuels are NOT the only way to improve your lot in life. For example, my customers lower their bills and their carbon footprint by investing in renewable energy. Now will their unused fuel be used by citizens of 3rd world countries? I suggest you look at telephones. It used to be, in Guatemala, that each town would have one phone and people would line up to use it. In more remote sections, the people would walk over to the next town. The problem was the fixed cost of running telephone lines. Now these communities are served by multiple cell phones. It turns out it is cheaper to throw up cell towers than it is to run thousands of miles of copper wire. That is a better analogy, and what the right wing in the US doesn't understand. We can create solutions that are BETTER than fossil fuel. We can lead the world and make serious money, or we can sit on our hands and say "well if we don't use it someone else will." It is a logical fallacy, pure and simple. -
actually thoughtful at 08:53 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
RSVP - you seem to be a good candidate for solar space heating. That would minimize your costs & minimize your CO2 footprint. Don't you sometimes argue that winters are getting worse? But here you say you are paying more for less fuel, meaning that winters are less severe? (Or did you invest heavily in conservation?) -
actually thoughtful at 08:50 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Dana - I said "over 60%" You said "90%" both are correct. My point stands, that the majority of us could, in fact, power our transportation needs with a Nissan Leaf (or equivalent) and 8 solar PV panels. -
RSVP at 07:27 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Marcus #79 "Also, try living here in Australia where every Summer we're getting increasing number of nights that are *above* 20 degrees C-thus forcing us to consume more electricity to keep our homes cool at night." The more people use air conditioners, the warmer it gets. You are in fact saying that more and more energy is going into "cooling", when in reality it is going into heating the ambient temperature (i.e., urban heat island, waste heat problem, etc.)Moderator Response: [muoncounter] As you will no doubt recall, we have a waste heat thread and UHI threads here and here. -
Timothy Chase at 07:05 AM on 8 March 2011Blaming the Pacific Decadal Oscillation
When quoting (82) from the webpage that nofreewind (76) had referred us to:However, the Hadley Centre's real-world plot of radiosonde temperature observations shown below does not show the projected CO2 induced global warming hot-spot at all. The predicted hot-spot is entirely absent from the observational record. http://www.friendsofscience.org/assets/documents/The_Saturated_Greenhouse_Effect.htm
... I pointed out that the Friends of Science claim that "the predicted hot-spot is entirely absent from the observational record" is at best cherry-picking the studies, and gave two examples of studies that claim to have found the "hot-spot" where the warming trend is higher in the mid-troposphere than on the ground. However, I appear to have missed the bit where they referred to the hot-spot as being the "projected CO2 induced" global warming hot-spot. Such words are strongly suggestive of the often-repeated claim that the hot spot is a signature of CO2 induced warming -- and if the temperature profile don't fit you must acquit. Chris Colose reminds us that the hot spot is actually the signature of any global warming, whatever the forcing. Please see:Tropospheric warming in the tropics is a signature of greenhouse warming, but it is more accurate to say that it is not a unique signature (i.e., you get this "hotspot" with all types of forcings). The 'hotspot' arises due to the moist adiabat. In the extra-tropics you do not don't expect the lapse rate changes to be so dominated by moist convective effects. Skeptics/Denialists Part 2: Hotspots and Repetition Posted on December 20, 2008 http://chriscolose.wordpress.com/2008/12/20/skepticsdenialists-part-2-hotspots-and-repetition
He also points out that it is part of a negative feedback, and if the "hot spot" isn't there then global warming will actually be somewhat stronger than we expect. More evidence that Friends of Science should not be regarded as a trusted source of science news... In any case my apologies for not getting this in the first time around.Moderator Response: Also see the Skeptical Science Argument "There’s no tropospheric hot spot." -
stevee3906 at 06:33 AM on 8 March 2011The Climate Show Episode 8: Kevin Trenberth
It sounds like the science is "Mixed" on hacking or leaking....so are those that insist on hacking then "deniers" ? If they were leaked then that would be a team member who for whatever reason didn't like what was going on. The topic is HidetheDecline, thus the source is part of the topic.Moderator Response: [muoncounter] Perhaps you should listen to the show; there are many topics. The flap over "ClimateGate" has a number of existing threads. -
angusmac at 06:32 AM on 8 March 2011Icing the Medieval Warm Period
Moderator @#22, "For posterity and context, current northern hemisphere temps greatly exceed those of the MWP." I suggest you can only come to that conclusion by using current instrumental temperatures and then comparing them with 1000-year old proxies. This methodology can be incorrect. The correct methodology should be to compare current proxies with past proxies. Let me explain further by utilising Ljungqvist's (2010) reconstruction which is shown in Figure 1 below.
Figure 1: 2000-Year NH Temperature Reconstruction (after Ljungqvist, 2010)
I have plotted the MWP peak temperature as the red line and the modern proxy peak as the blue line on the reconstruction in Figure 1. The instrumental data are deleted for clarity. It is evident from Figure 1 that the MWP peak is 0.11 °C warmer than the modern proxy peak decadal mean (1980-1989).
However, Tom Curtis in #136 @ SkS Hockey Stick Own Goal pointed out that the GISS data show that 2000-2009 mean temperature to be 0.18°C higher than 1990-1999 decadal mean. Therefore, I show Ljungqvist's data in greater detail for the modern instrumental period in Figure 2. The data for Figures 1 and 2 is available from NOAA (here).
Figure 2: Modern NH Temperature Reconstruction 1860-1999 (after Ljungqvist, 2010)
I have restored Ljungqvist's instrumental data in Figure 2. I have also added 0.18°C as an estimate of the 2000-2009 instrumental decadal mean. This is shown as the dashed red line. Several features are evident from Figure 2, the most important of which are as follows:
- There is a very good correlation between Ljungqvist's proxy temperatures and the whole of the pre-1990 instrumental data. Thereafter, they diverge. This is a good illustration of the aptly-named "divergence problem."
- The MWP is approximately 0.11°C warmer than the modern-day proxy temperatures, including the 1980-1989 decadal peak.
- The modern instrumental data for 1990-1999 of 0.39°C and 2000-2009 of 0.57°C exceed the MWP proxy peak temperature by 0.19°C and 0.37°C respectively.
- Notwithstanding item (3), the MWP peak is 0.14 °C higher than the 1990-1999 proxy temperature. Therefore, it is possible to infer that an "instrumental" MWP peak would be approximately 0.14°C higher than the 1990-1999 instrumental temperature, if there were a linear response between proxy and instrumental data. However, to be safe, it may be better to use the 0.11°C difference between the MWP and modern proxies. This would correspond to a MWP peak "instrumental" temperature anomaly of 0. 39 + 0.11 = 0.50°C.
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muoncounter at 06:22 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Rob: "how is all that coal going to be extracted from the ground and transported?" I'd be happy to leave coal exactly where it is; in the ground. There are LPG-powered vehicles in use; school buses, light-duty trucks, even a 5.9L big rig engine. What about biodiesel, which could stretch dwindling fuel stocks for some years? All I'm saying is that the sum total of what Gilles seems to favor results in a do-nothing attitude. It is born out of the pre-conception that atmospheric CO2 is not an urgent problem, so we can get by on fossil fuels as long as they last. That is unfortunately a path we are taking, but not one we should be taking. Counter the argument 'we can't afford to reduce emissions' with 'we can't afford what will happen if we don't'. -
Chris G at 06:14 AM on 8 March 2011Interactive animation of the climate change impact on agriculture
Camburn, "I was not surprised to see a rise in production from more warmth. That is pretty much a given." Yes, because we've all seen how the increased warmth in Russia lead to higher yields last year. On a more serious note, I'm curious to know if the model accounts for precipitation shifts. I'm guessing not really, but I would expect that changes in the pattern of precip would have a more dramatic affect that changes in mean temperature. For instance, this year China is having a drought that will affect their wheat production. There are good indications from the field lately that rain bands are on the move in response to higher temperatures. -
logicman at 06:02 AM on 8 March 2011Icing the Medieval Warm Period
Re: comment #78 - moderator response. Many thanks for the warm welcome! Yes, I did mean the Spielhagen et al paper. I mistakenly copied from my recent urls list the one above Spielhagen. The link I mistakenly posted is a paper suggesting the possibility of sea ice recovery in 2 years after an ice free summer. I have been 'lurking' here for far too long and thought it was about time I signed on/in/up. Best regards, Patrick Lockerby http://www.science20.com/chatter_boxModerator Response: [DB] Patrick, I think your html for the no follow code string in your SkS Sign-on ID is hashed (plus I'm not sure that the no follow string will work there anyway, but it's worth a try; for some reason it shows up as logicman w/ no link in the Recent Comments window, but it's hashed up on the actual threads). Between the left-arrow symbol and the right-arrow symbol should be this string: a rel="nofollow" href="http://www.science20.com/chatter_box" -
Rob Painting at 05:56 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Muoncounter @ 83 - According to World coal: "there is enough coal to last us around 119 years at current rates of production." Not going to be exhausted any time soon. Probably not, but if oil runs out, how is all that coal going to be extracted from the ground and transported?. -
Rob Painting at 05:53 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Dana 1981 @ 82 - No it's not. Transportation can be accomplished with electric vehicles to a large degree Personal transport?. Yes. Heavy machinery?. No. We still have a long way to go, and better get cracking in creating something to replace it. -
hank at 05:22 AM on 8 March 2011Climate sensitivity is low
http://www.barrettbellamyclimate.com/page17.htmModerator Response: Please provide some context for links. Link-only comments will be deleted. -
muoncounter at 05:18 AM on 8 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Gilles #66: "Even if they halved their energy consumption ... I'm just saying this will not reduce the overall consumption. And it won't either reduce the total amount of fossil fuels that we can extract" I don't follow that reasoning at all. Gilles#72 "I am arguing that we MUST do anything we can to spare FF, first because they are being exhausted ... " According to World coal: "there is enough coal to last us around 119 years at current rates of production." Not going to be exhausted any time soon. Add in (from USEIA): "The combustion of coal, however, adds a significant amount of carbon dioxide to the atmosphere per unit of heat energy, more than does the combustion of other fossil fuels" and your argument reduces to one of failure to act. -
Bob Lacatena at 04:57 AM on 8 March 2011Interactive animation of the climate change impact on agriculture
I think one major failing in the model, one which can make climate change seem good by increasing crop yields, is the question of appropriate precipitation ("appropriate" as in how much, how often, and at what time of year from the crop's perspective). That is probably part of the difference in the low/mid/high latitude setting, but since precipitation changes aren't entirely governed by latitude, I'd rather see something just a little more elaborate... either a "precipitation gauge" which responds in concert to altering temperature (i.e. not a control itself -- you change temperature, and that changes precipitation) with a range of changed values, and therefore a range of expected crop yield due to the precipitation range, or else perhaps more simply 3 or 4 separate "crop yield" boxes (zones), to represent various general climate zones ("wet", "arid", etc.), perhaps each with a percentage to show how much of the world will fall into that category in various scenarios. I guess my main point is that I think that changes in precipitation are a far more important and damaging factor in the long run, and it's the intersection of the two (temperature and precipitation changes) that are going to really hurt crop yields... you have to get better temperatures and better precipitation to increase crop yields, while only one of those two needs to drop to greatly reduce crop yields. And in fact, in some circumstances what would otherwise be a productive increase in temperature but combined with a reduction in precipitation, even if only for a several week span during an important part of the growing season, could exacerbate the precipitation problem and make things worse. That is, the effects of changes in temperature and moisture aren't simply additive, but interact in a complex way. -
hank at 04:32 AM on 8 March 2011Climate sensitivity is low
http://www.gfdl.noaa.gov/blog/isaac-held/2011/03/05/2-linearity-of-the-forced-response/ hat tip to: http://scienceblogs.com/stoat/2011/03/dr_roy_spencer_is_sad_and_lone.php -
hank at 04:29 AM on 8 March 2011Climate sensitivity is low
> what's next, redefining the laws of physics ....? Chuckle. Yep. http://www.google.com/search?q=%2Bspencer+%2Bpoptech+%2Brefute
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