Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2029  2030  2031  2032  2033  2034  2035  2036  2037  2038  2039  2040  2041  2042  2043  2044  Next

Comments 101801 to 101850:

  1. actually thoughtful at 05:23 AM on 11 December 2010
    Renewable Baseload Energy
    Michael Sweet - I would like to know the insolation levels during the summer - does the heat come with notable cloud cover? Here is an overview of the idea: http://en.wikipedia.org/wiki/Solar_air_conditioning#Solar_thermal_cooling (also look at the desiccant bit higher on the Wikipedia page). One possibility I would examine is a ground source heat pump (GSHP) and PV to balance out the solar load (in other words, after the GSHP reduces the load by ~75%, use PV to supply the electricity to run that GSHP compressor). You can't put enough PV on a rooftop to natively provide AC or heating (too much load). But once you apply a renewable strategy to eviscerate the load, you can use PV or residential wind to mop it up. Note this strategy relies on "grid banking" - putting more in than you use for 6 months of the year, balance for 3, and withdraw for high summer. If your house is well insulated, you might over-cool the house during peak solar (9-5 (summer)) and let it slowly warm through the evening (this is only to match PV output to AC load - it doesn't serve any other function, and may not be desirable when you look at the whole picture - I am keeping us relevant to the original post...). The cheapest "solar cooling" is evaporative cooling - little application in FL, but huge in the southwest (although it ought go hand-in-hand with rainwater harvesting so as to not stress water supplies).
  2. Ice data made cooler
    JG I would like to see units. Just something my profs drove into me from day one. There is insolation and there is albedo. Where the albedo is extremely low the energy will be retained at the surface and not re-radiated. Where the albedo is moderate to high the insolation energy will try to get back out by radiation. Is there some way you can show albedo at various latitudes over time?
  3. A Cloudy Outlook for Low Climate Sensitivity
    I think it's a waste of time arguing with Camburn over the statistics here. He's clearly demonstrably wrong in many ways, and he's clearly not going to admit that he's wrong. I know we try to avoid the term on this site, but I'm sorry, that's denial. It's not relevant to this article anyway, so I suggest we just let Camburn have his denial and move on. For the record though, Chris G is correct that the generally accepted confidence level of 95% is quite arbitrary, not that it matters since the temperature trend is statistically significant at this level, whether Camburn will admit it or not. Spencer's hypothesis seems rather bizarre to me. Cloud cover is what controls ENSO cycles, yet ENSO cycles generally happen on a pretty regular basis. So what then is causing cloud cover to change on this regular basis? Wait, let me guess - 'natural cycles'?
  4. It's not us
    Continuing a reply to a comment here. "if one presupposes that human activity in some way affects the temperature of the Earth" Let's think of some things that human activity affects that we might agree on. I won't bother to provide citations for these things; you can find them quite easily if you want: a. ozone - remember that 'hole' that we could close by restricting CFC use? b. smog - air pollution controls have successfully reduced smog problems (caused in part by auto exhaust) in Los Angeles. Look also at successful pollution controls in central Europe put in place in the early 90s. c. acid rain - caused by SO2 emissions from industrial activity, reduced by scrubbers. d. dust clouds/storms - over farming in the US dust bowl; coal-fired power plants and urban pollution in Asia. e. CO2 -- there are a lot of studies measuring 'urban CO2 domes' that are directly tied to daily, weekly and seasonal traffic patterns. Of course, there is all that annual CO2 input from fossil fuel consumption. f. clouds - we know how to 'seed' clouds and make rain, at least in limited areas. How many of these human activities 'affect the temperature of the Earth' in some way? Some might say they all do. Here's what the experts say (I've quoted this a number of times and will continue quoting it wherever necessary until John says enough): Weather in a given region occurs in such a complex and unstable environment, driven by such a multitude of factors, that no single weather event can be pinned solely on climate change. In that sense, it's correct to say that the Moscow heat wave was not caused by climate change. However, if one frames the question slightly differently: "Would an event like the Moscow heat wave have occurred if carbon dioxide levels had remained at pre-industrial levels," the answer, Hansen asserts, is clear: "Almost certainly not." The frequency of extreme warm anomalies increases disproportionately as global temperature rises. "Were global temperature not increasing, the chance of an extreme heat wave such as the one Moscow experienced, though not impossible, would be small," Hansen says.
  5. We're heading into an ice age
    #174: "I'm not the one expecting that warming should be linear." Great! That means you admit there is warming going on, which promotes you out of the 'four legs good, two legs bad' 'no, its not' crowd. "if one presupposes that human activity in some way affects the temperature of the Earth." I'll go out on a limb and guess that you don't. There are many threads that more appropriate; you should look at them and see how well your opinion holds up. I'll continue this comment here.
  6. A Cloudy Outlook for Low Climate Sensitivity
    Camburn... Please inform us as to what 93% does not cut it and why? I mean, if you're going to cut down the data set to present a conclusion that falls just short of statistical significance you need to back that up with a meaningful reason why you do so. If there is no specific reason for choosing the 1995 to present data set then, since is falls short of statistical significance for either warming or cooling, then you need to pull back and add data to the set. Pull back until you get a statistically significant data set. Back to say, 1990. Then what do you find? If you absolutely must have 95% confidence or better then you need to use enough data to get to that confidence level. Do this and you absolutely will find unequivocal warming.
  7. There is no consensus
    @NQoA: what's your point, exactly? That we should trust experts on a particular matter because there's relatively few of them? I know deniers usually aren't motivated by logic, but you sir take the cake.
  8. We're heading into an ice age
    @NQoA: I think your point is that you're going to disbelieve the science, whatever it says, as long as it does not conform to your preconceived notions about the reality of AGW. "I'm not the one expecting that warming should be linear." Nor is anyone who understands the science, despite what you seem to be insinuating. Stop trying to set up that strawman argument, no one's buying it. "I didn't miss anything, I was pointing out that the AGW team - up until recently, promoted the expectation that the ice sheets and glaciers would continue to recede" They have, when you look at it globally. Of course, when you engage in such cherry-picking as you've demonstrated, that doesn't really matter, does it? Is that what skeptics have been reduced to? I remember when we had quality opponents, such as BP - not amateurs such as NQoA who still try to say it's not warming...
  9. Renewable Baseload Energy
    Actually Thoughtful, I live in Florida. It is about 94F every day in summer and about 80F at night. Can solar be used to cool the home in these conditions?
  10. A Cloudy Outlook for Low Climate Sensitivity
    Camburn, In addition to what others have posted, if you are going to use statistics, you might as well try to understand what they mean. A 93% confidence means that there is a 93% chance that the observed pattern is 0.93 likely to have not been caused by the inherent variation of the data. That leaves 0.07 for the chance that it is, which in this case, means that at the time the test was made, your statement that "we have not warmed for the past 15 years" had a chance of being correct of 0.07. So, if you are not willing to choose a course of action based on a 0.93 chance of warming, I don't see why you would expect anyone to choose a course of action based on a 0.07 chance of no warming. Yet, that is what you are proposing. Why is that? Nevermind that in the larger context, the window of time that you have chosen to take a stand on is only a fraction of the time for which we have plentiful information about, and the rest of it supports the 0.93 probability position. Lastly, the 5% rule is not really golden; its pretty arbitrary.
  11. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Re: NQ/A (108) That depends. If you are asking me to prove the non-existence of something (which would be a silly request), then I could not do that. Scientists follow the Scientific Method:
    1. Define the question 2. Gather information and resources (observe) 3. Form hypothesis 4. Perform experiment and collect data 5. Analyze data 6. Interpret data and draw conclusions that serve as a starting point for new hypothesis 7. Publish results 8. Retest (frequently done by other scientists)
     The hypothesis that is best supported by all of the data is the one that gains eventual acceptance by other scientists. Over time, an accepted hypothesis can be verified sufficiently to become a theory. That is where the field of global warming is: Theory. Per the National Academy of Science in their publication Advancing the Science of Climate Change:
    "A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems…. Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities."
     “Very likely” means a greater than 90% likelihood of probability. I.e., pretty certain. So, in order to overturn the anthropogenic attribution of global warming, what must a scientist do? Find a viable physics-based alternative to one of the points in this chain:
    1. Increasing the level of a greenhouse gas in a planet’s atmosphere, all else being equal, will raise that planet’s surface temperature. 2. CO2 is a greenhouse gas. 3. CO2 is rising. 4. Therefore (given 1-3 above) the Earth should be warming. 5. From multiple converging lines of evidence, we know the Earth is warming. 6. The warming is moving in close correlation with the carbon dioxide. 7. The new CO2 (as shown by its isotopic signature) is mainly from burning fossil fuels. 8. Therefore the global warming currently occurring is anthropogenic (caused by mankind).
    Plenty have espoused alternative theories on blogs, but none have been able to survive scrutiny in a peer-reviewed publication. So have any scientists, using all of the data, been able to break the above chain? None that I'm aware of. Fossil fuel interests spend hundreds of millions of dollars in the US every year to lobby against any controls on fossil fuels and CO2 emissions. Vast riche$ await anyone who can scientifically break the chain of evidence & show the AGW is a non-worry (I'd chip in a couple of hundred myself). Spencer is probably the closest to a competent scientist among the denialarati. Per the Dessler/Spencer emails, Spencer believes clouds cause ENSO... So the real question is: have you found any scientist that claims to have overturned AGW? If so, who was it? In what peer-reviewed publication was their work published? Have they presented their proof to those meeting in Cancun yet? I have no wish at all for AGW to be real. You have no idea the amount of sleep I've lost over the years because of it. The thought of the world I bequeath to my young children and their children... NQ/A, with the caveat that this is a hypothetical question for thought purposes alone and answering will not constitute an admission of belief in AGW, if AGW is real and all of the predictions come true, what will you say to your grandchildren when they come to you and ask you what you did to try and stop it? Just curious. The Yooper
  12. A Cloudy Outlook for Low Climate Sensitivity
    Norman the disagreement is specifically on ENSO, not generally on warm/cold ocean less/more clouds. It's stated explicitly by both Spencer and Dessler, it's ENSO that causes less clouds or less clouds that produce ENSO? The former mechanism is straightforward, the latter is really misterious and not even guessed by Spencer himself.
  13. A Cloudy Outlook for Low Climate Sensitivity
    #115 syphax, I went to the link you posted (RealClimate). I read the posts below and it is the same I read everywhere including this site. Many questions and a lot of opinions but still no real solid undebatable answers. CO2 will produce warming of the Earth. How much is the big unknown. The cloud issue seems to be the most mysterious of all the factors. No clouds or water vapor feedback and a doubling of CO2 gives a 1.2 C warmup. That is about the only number I see given that most agree to (both camps). On the cloud issue I believe Spencer's view has a logical basis. The observation is less clouds and a warmer ocean. One conclusion feels a warmer ocean produces less clouds, another feels that the fewer clouds warm the ocean (more direct solar radiation gets absorbed). If not for clouds the Earth's total albedo would be around 0.15 and the Earth would be much warmer (The albedo calcualtor indicates about 20F). With clouds the Earth's albedo is 0.3. So some types of clouds may warm the Earth depending upon the thickness, the location and the time of cloud development (night clouds keep the night from cooling as much, thick day clouds in the summer greatly reduce the high temperature, anyone can get this information from personal observations), but overall clouds must cool the earth because of their overall effect on albedo.
  14. How do we know CO2 is causing warming?
    henry justice @226 Problem is, the bottle would need to be as tall as the atmosphere, in order to mimic the pressure gradient. And be perfectly insulated. And be wide enough to allow convection without wall effects. And be connected to a series of other bottles to mimic heat transport through the atmosphere to different latitudes. etc. Let us know how you get on with that one.
  15. Stratospheric Cooling and Tropospheric Warming
    Oh and tom, there is a thread over at Science of Doom about this stuff.
  16. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis at 13:23 says "Specifically, while it only takes a few hours to restore thermodynamic equilibrium in the atmosphere by conduction, it can take as much as 50 days to do the same by radiation." Again, the reason for this, is the opacity, radiation, is an inefficient mover of energy in the lower layers of the atmosphere, where it is opaque, because what is radiated, is absorbed in a very short distance. As the atmosphere thins with altitude, the path length shortens, radiation travels further before it is absorbed. When air convects, it looses its energy, performing work, displacing the air above it, this energy is put into the air it is displacing, this is why it cools... Now if radiation wasn't moving this energy, out of the upper layers of the troposphere at the rate convection was carrying it there, the energy would accumulate. And because energy is still coming into the system, it would lead to a build up of energy in the system, raising the T at all layers. And it would continue to do this, until it had heated the higher layers(shorter path length) up enough until they were radiating the energy away. Convection, cannot take energy out of the system, it does not work in a vacuum. And energy cannot be created or destroyed, it can only come into the system, via radiation, and leave via radiation. If more is coming in, than what is being radiated away, the system will accumulate energy, until it can radiate the incoming away. You are violating, the first law of thermodynamics. For your second point, the same applies, it dosnt matter that at the surface, it is warmer and radiating more, because the energy is simply swapping between molecules, This is why convection occurs, energy accumulates... In the tropics, it receives a lot more energy from the sun than at the poles, there is vastly more water vapor in the atmosphere, to much higher levels(due to convection)... again making the atmosphere opaque to radiation, inhibiting it. Causing convection to much higher altitudes, until the energy can be lost via radiation. The bottom line is, if convection was moving more energy up to the tropopause, than what was being radiated away, it would heat, moving the tropopause up, until it got to a level, that it could radiate the energy away. You have to be able to explain, where your energy is? It doesn't vanish. Now if there was no solar absorption in the upper atmosphere, we would have a T gradient, starting from the surface T, and decreasing until the outer layer at 2.7K The back ground T o space.
  17. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Daniel - I'm curious, in your opinion, are there any "competent scientists" that do not believe in AGW?
  18. We're heading into an ice age
    muoncounter - I'm just wondering, what do you think my point was?
  19. There is no consensus
    " "Do you think human activity is a significant contributing factor in changing mean global temperatures?" (Doran 2009). … 97.5% of climatologists who actively publish research on climate change responded yes." That is exactly 75 people. "There are three kinds of lies: lies, damned lies, and statistics"
  20. The Scientific Guide to Global Warming Skepticism
    Great job on the "Guide." I hope you can do an expanded version and get it in bookstores so the general public will have access and you can generate some income.
  21. We're heading into an ice age
    #174: "I didn't miss anything," Right. Your 'favorite headline' cherrypick stated this glacier was advancing; you tried to make something of the legitimate statement made by a knowledgeable scientist that he couldn't explain everything. As if that's some kind of weakness in the whole picture. And you missed the whole bit about the glacier being in equilibrium -- or else you wouldn't have used that poor an example to illustrate your 'point'. Here's a glaciar nearby that's not in equilibrium: Upsala Glacier, Argentina, 1928 Same spot, 2004: This is not how an ice age is supposed to look. Any questions?
    Moderator Response: {Daniel Bailey} Topical of you to bring this glacier up. Check this out:
  22. We're heading into an ice age
    CBDunkerson (171) - would you be kind enough to send me a couple of links to examples, pre 2005, were the IPCC or friends specifically stated that they expected the sea ice extent to increase, glaciers to increase or record cold temperature to occur post 2005. Not some vague statement that could be interpreted any which way - but, an explicit statement along the lines of: regardless of the current warming trend, we fully expect glaciers to occasionally expand and record cold temperatures to occur. muoncounter (172) - I didn't miss anything, I was pointing out that the AGW team - up until recently, promoted the expectation that the ice sheets and glaciers would continue to recede; as evidenced by the statement: 'We're not sure why this happens'.. On the question of "are we heading into a new ice age?" - that only matters if one presupposes that human activity in some way affects the temperature of the Earth. You, obviously, presuppose that we do. archiesteel (173) - I'm not the one expecting that warming should be linear.
    Moderator Response: Well, you could start with this post: It’s freaking cold!
  23. Arctic icemelt is a natural cycle
    Re: NQuestofApollo (17) Perhaps if you had read Dr. Rivera's extended comments in the longer version of the article here:
    "One hypothesis for the 3-mile-wide (5 kilometer-wide) Perito Moreno's advance is the glacier's apparent insensitivity to changes in what glaciologists call the equilibrium line on glaciers, Rivera said. Roughly equivalent to the snow line, the equilibrium line is the elevation above which the glacier is growing, due to snow accumulation, and below which the glacier is melting. When this line moves higher up a hill or a mountain due to rising temperatures, for example, more of the glacier is situated in the melting zone, and the glacier retreats. But because Argentina's Perito Moreno glacier is so steep in the area where the equilibrium line falls, climate shifts don't impact the line's movement much, at least as it relates to the height of the mountain, Rivera noted. As a result, the amount of of ice lost or gained is minimal. It could also be that Perito Moreno simply hasn't got all that much to lose. The lake where Perito Moreno ends—Lago Argentino—is shallower than the bodies of water at the ends of most glaciers. Most glaciers calve, or release ice, in deep water, but not Perito Moreno, where the calving rates are higher than on other Patagonian glaciers. That means less of the glacier is in the melting zone below the equilibrium line. As heavy snowfall above the equilibrium line pushes the glacier downhill, the glacier breaks up when it hits the lake, Rivera explained. Such impacts kept the glacier from growing longer when the climate was cooler, and thus more likely to expand, he said. If Perito Moreno had extended into a deep lake area, it would have become a longer glacier, and Earth's recent warming trend would be causing the glacier to melt and its ice to retreat more easily, Richard Alley, a glaciologist at Pennsylvania State University in University Park, said in an email. "Instead, we have a shorter glacier, with less [of a] zone where the warming can cause melting, but a large high-elevation [snow and ice] accumulation zone," Alley added."
    Forming an opinion based on an incomplete news article on one glacier that happens to be advancing at a time when glaciers worldwide are in retreat is cherry-picking. No one said glacial retreat would be linear and uniform. Perito Moreno, for the reasons surmised, is one of the exceptions to the overall trend. Noise in the data. For more on glacial changes, go to Mauri Pelto's blog. The Yooper
  24. The human fingerprint in the seasons
    Here's an alternative to the alternative theory: Shown below is a graph of UAH NH data through 11/2010, with 3 month averages for winter (DJF) and summer (JJA). The linear trend for winter (blue) is 0.23 deg/decade vs. 0.14 deg/decade for summer (red). Not to belabor the obvious, but "if greenhouse gases are causing global warming, we expect to see winters warming faster than summer". Yep, 64% faster.
  25. How do we know CO2 is causing warming?
    The real way to run a CO2 warming experiment is to use just one bottle or jug, have a little water in it, use air for the first run of temps and then pump in the CO2 to 760 ppm, then run a 2d set of temps, in both instances using the same probe and warming lamp. Hmmm! I think I will try it myself.
  26. Arctic icemelt is a natural cycle
    @Argus: no one said CO2 was the only forcing. To claim otherwise would be a type of strawman fallacy. The point you're apparently missing is that, no, the climate change we are currently experiencing is not like what has happened before. We have a pretty good idea of why climate changed in the past, and none of the various circumstances that provoked past change is at play today What *is* different, of course, is that this time we're pouring gigatons of CO2 in the atmosphere, and that CO2 is causing temperatures to rise. Just to make things clear, though: are you in fact disagree with NQoA? Because the latter seems to think there is no warming, while you claim the warming is natural. Aren't going to argue with NQoA as well? After all, he's also disagreeing with you. I'd love to see some "skeptics" break the unspoken rule once in a while, but I don't think this is going to happen here...
  27. Arctic icemelt is a natural cycle
    NQuest @17: Perhaps without realizing that the discussion was to be moved to this thread, muoncounter provided you an explanation on the 'ice age' thread. Please note that he cites directly from the link you provided. The article's own tone seems to be in opposition to the use to which you wish to put it, a behaviour which seems lamentably common among contrarians who visit this site. The article suggests that this glacier is certainly anomalous, but since the rest of the world's ice (as documented in this very post or handily summarized with this search of SkS) continues to decline, I hardly see how it can present a major challenge to the science supporting AGW. Certainly I would conjecture that one factor in the Perito Monero glacier's stability would be an increase in precipitation (specifically, snowfall at the glacier's source), which follows from an increase in atmospheric water vapour, which follows from (wait for it...) warming temperatures. Sooner or later, though, if temperatures continue to rise, Perito Monero will follow its fellow glaciers into decline. At any rate, it seems to me that bringing up Argentine glaciers is a complete non sequitur - perhaps even a red herring - when it comes to discussions specifically focused on Arctic sea ice decline.
  28. Arctic icemelt is a natural cycle
    @NQoA: because they're not certain about the particular characteristics of that glacier that make it resist the global trend towards glacier retreat. Again, no one said all glaciers would recede at the same time, or at the same rate. Given the number of glaciers on the world, some are bound to react differently. The fact remains, however, that an overwhelming majority of glaciers are retreating.
  29. Arctic icemelt is a natural cycle
    e (16) - Could you please explain to me why is it that the glacialist, when discussing the expansion of the glacier made the statement, "We're not sure why this happens".
  30. A Cloudy Outlook for Low Climate Sensitivity
    Camburn: As far as staticistical temps.....2010 is not over. I still stand by my statement. Also, 93% does NOT cut it. 2010 will be over in about three weeks. Perhaps you'll concede the point then? I'm sure there are other people here who will remind you, if I forget.
  31. actually thoughtful at 14:23 PM on 10 December 2010
    Renewable Baseload Energy
    Source for PEW data above: http://www.pewclimate.org/technology/overview/buildings
  32. actually thoughtful at 14:21 PM on 10 December 2010
    Renewable Baseload Energy
    Quokka - I run a company that specializes in renewable based heating systems. So the we is me. Design temperature is -2F (-19C). Design temperature means the coldest temperature you reliably get every winter. I will publish my results in the next 6 months (in a trade journal - there is no new science here, just intelligently using current technology, with a few of my own innovations). According to the PEW Center - 51% of a buildings energy usage comes from HVAC and water heating. I found multiple sources for buildings using 39% of total US energy use was for buildings. So by cutting 1/2 of 40% by 75% we have as our total pie 15% of total US energy usage! So, following the basic rule of ethics - is it generalizable? Yes! If all buildings followed our recipe, we could cut emissions by 15% - that is basically the entire Obama commitment to climate change (obviously to weak). Now some caveats - our work reduces natural gas, electricity (for water heaters - site specific) and propane - natural gas is called the "cleanest" of fossil fuels, and propane is slightly worse, but not as bad as electricity. Not all buildings are ideal candidates for solar thermal (but there is always geothermal - more than one way to get to zero energy). However, reducing electrical loads is at least as easy. Obviously reducing the need for heating/cooling and electrical use is the easiest path to reducing building loads. But we can retrofit a building with solar space heating at a similar-if-not cheaper cost than replacing all the glass and upgrading all the insulation (both, with a smaller system from us is most preferred). And these improvements pay for themselves over time. A building's mortgage is fixed (does not go up with inflation) but fuel prices are variable (and in fact, for the last 43 years (as far back as the data goes) have increased at roughly double the average inflation rate (fuel rate of inflation is 6.5% per year). I am 100% against greenwash - and this is, indeed planetary scale. As in think globally, act locally. One greenwash myth is that we need utilities and governments to do this *for* us. Not true. Each of us can and should take action (as should utilities and governments). Our lives are improved by this act. There is a HUGE satisfaction to taking control of your own energy destiny in your own home or place of work. Try it before you talk it down.
  33. A Cloudy Outlook for Low Climate Sensitivity
    Daniel@ 120: I posted the url so that people could read the paper. The url you posted takes you to the publisher, and is not readable unless you are a member. The paper deals with observed cloud feedback verses modeled cloud feedback. Rather than inflect my opinion, I present the literature for each to interpret. As far as 119: We shall see.
  34. A Cloudy Outlook for Low Climate Sensitivity
    Re: Camburn (118) Generally it is both good form to provide some insights (if you have any) into what readers of a linked source can expect to find therein and to provide a link to the published version of the paper, not a submitted version. The Zhang paper is fairly long in the tooth (submitted in 2007, accepted in 2008, published in 2009) for a cloud paper. Compare and contrast it to this recent paper by Dessler et al (to which Albatross has already linked to previously in 114 and to which dana1981 has then referred to above at 117) which find a net positive contribution from clouds. (119) Enough data has come in on 2010 to make even the portion available for 1995-2010 (inclusive) statistically significant. So you are wrong on that. The Yooper
  35. Stratospheric Cooling and Tropospheric Warming
    Joe Blog @196, having now understood what you are saying, I will not procede to criticize it. First, although the mechanism you describe sounds plausible, you fail to account for the characteristic rates characteristic rates of convection and radiant transfer. Specifically, while it only takes a few hours to restore thermodynamic equilibrium in the atmosphere by conduction, it can take as much as 50 days to do the same by radiation. This difference of rates is the primary reason why convection dominates radiation as a means of energy transfer in the atmosphere, and is still relevant at the tropopause. Given the example in 195 of a warm air parcel rising to 8km altitude, this means it would reach an equilibrium temperature by radiation over the period of about a month, or more. But it would still be able to reach an equilibrium temperature with the surrounding air in a few hours by convection, ie, by continuing to rise. Consequently, on these grounds, we would expect convection still to dominate as a heat transfer mechanism within the atmosphere. Second, radiant transfer is related to the fourth power of temperature, while heat conductive heat transfer is related to the difference between the temperature of the heated or cooled air parcel (Tap) and the temperature of the ambient air (Te) by the relation such that, a = g(Tap-Te)/Te , where a is the acceleration on the air parcel, g is the gravitational acceleration, and a is the acceleration of the air parcel. Therefore, given a 1% rise in temperature, we would expect heat transfer by convection to increase by about 1%. Heat transfer by radiation, in contrast, should increas by about 4%. Because radiant transfer becomes more effective with rising temperature, if radiant tranfer dominated, we would expect a rise in temperature to decrease the altitude at which radiant tranfer first started to dominate. Consequently, if the altitude of the tropopause where determined by where radiant energy started to dominate for heat transfer, then incraseing atmospheric temperature should decrease the altitude of the tropopause. Instead, the tropopause is highest in the tropics and lowest at the poles. Indeed, even cold fronts will lower the tropopause. "As can be seen in the figure above, the tropopause altitude steadily drops from about 12.5 km to 11 km as the DC8 flies west from The Azores toward a cold front in the western Atlantic Ocean. At ~10:15 UT there is evidence of stratospheric tracers (O3, NOy up, CO down) from in situ sensors. At the same time, the tropopause altitude drops abruptly more than 1 km and MTP sees a warm finger of air extending through this tropopause drop, apparently because the descending stratospheric air is being adiabatically heated. Later, at 11:17UT the Langley Research Center DIAL lidar saw the beginning of a stratospheric intrusion at the same time that MTP saw a second tropopause altitude drop" (Caption quoted from source.) Finally, I think my comments about the mesosphere in 193 above are still relevant.
  36. A Cloudy Outlook for Low Climate Sensitivity
    Steven: As far as staticistical temps.....2010 is not over. I still stand by my statement. Also, 93% does NOT cut it.
  37. A Cloudy Outlook for Low Climate Sensitivity
    This paper addresses cloud feedback: http://www.esrl.noaa.gov/psd/people/dezheng.sun/dspapers/Sun-Yu-Zhang-JC-revised.pdf
  38. Renewable Baseload Energy
    395 actually thoughtfull Who is this "we" and where does this "we" live? If you want this sort of thing to be taken seriously, provide some data and references. As always, the only thing that actually matters is planetary scale emissions reductions not feel good greenwash.
  39. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis lol, yup, but i did say transparent. Not non radiating, so this energy could be radiated away by magical atmosphere. But i recall coming to a similar conclusion thinking about a non radiating atmosphere.
  40. actually thoughtful at 12:06 PM on 10 December 2010
    Renewable Baseload Energy
    I should point out however, that solar water heaters can heat your home. Most people think about heating hot water - we are able to get over 75% of annual space heating and hot water from the sun. Right now, today. With payback less than a decade (and less than 20 years without rebates - meaning it is financially viable/smart now).
  41. Stratospheric Cooling and Tropospheric Warming
    Joe Blog @214, heat is also passed from surface to atmosphere by evaporation and transpiration. This, together with conduction would be enough to heat the lowest layer of the atmosphere to surface temperature, even in the absence of radiant heat transfer. And that in turn would be enough to generate convection. Even if only conduction were available, that would still raise the lower atmosphere's temperature to near surface temperatures. Because conduction is a slow method of heat transfer, the lower atmosphere would not have a large day-night cycle in temperature, although land surfaces would have a very large cycle. But even this slow method of heat transfer would heat the entire atmosphere up to at least the mesopause in the absence of any absorption of radiant energy by the atmosphere.
  42. Stratospheric Cooling and Tropospheric Warming
    Bob @201, as you surmise, temperature in the stratosphere is partially controlled by the mixing ration of Ozone to CO2, and if the flux of UV was constant with altitude, we would expect the highest temperature in the stratosphere to be where the highest mixing ratio was found. However, UV flux is not constant with altitude. Most UV-a, the most energetic form of UV, is absorbed above the level of maximum O3, apparently by the breakup of O2 (VGT @211). Considering UV-b, the next most energetic form of UV, nearly half is absorbed above 30km. Combined with the energy from UV-a, this should be sufficient to explain the temperature profile in the stratosphere. An interesting consequence of reduced O3 is that UV should penetrate further into the stratosphere. This should show up as a cooling at higher altitudes as they absorb less UV, but a warming at lower altitudes as more UV penetrates to the lower levels to be absorbed. The result is that in the lowest levels of the stratosphere, CO2 cooling is almost balanced by an ozone based warming, while in the upper levels they reinforce each other. PS: In preview, my first two images are not showing. I am leaving them in in case this is just a temporary bug, but in the mean time they can be found at the wikipedia article on the ozone layer.
    Moderator Response: [Daniel Bailey] Fixed links. TIP: When linking to Wiki graphics, make sure you click on the graphic itself, bringing up the page with just the desired graphic and no text. If you see text still, click on the graphic again to bring up the source storage position for that graphic. That should take care of it.
  43. Renewable Baseload Energy
    @392 archiesteel
    Re: RSVP's last bunch of tro...I mean, comments, I'd be curious to hear how quokka would respond to the "argument" put forth.
    I'd say RSVP is numerically challenged. Some things don't pass the smell test. But if pressed, I would suggest that the effects of a rise of 2-3 degrees in global temperatures on renewables is most likely unknown. Changes in cloudiness could affect all types of solar but which way?, PV might be slightly less efficient due to temperature, CSP relying on a heat engine may be slightly less efficent, wind - who knows? Regional climate change might be the major factor. Overall effect likely to be small. As for solar hot water systems heating the planet - don't make me laugh.
  44. Stratospheric Cooling and Tropospheric Warming
    Joe Blog at 214 And on refection I also fully with 214
  45. Ice data made cooler
    JK: the application file is Flash (.swf) which can be run by any browser that supports a flash player plugin. The code is written in Flash's scripting language called ActionScript. Contact me at my blog (http://www.brightstarswildomar.blogspot.com/) and we can figure out how to exchange files. jg
  46. Stratospheric Cooling and Tropospheric Warming
    Joe Blog at 215 I fully agree with that.
  47. Ice data made cooler
    JG: thanks for the comment. of course now everything is clear. The programme I was requesting is the one which generates the graph ... (is it in Java or Javascript or C++ or fortran?)
  48. Ice data made cooler
    RSVP, Oxygen is not very soluble in water while carbon dioxide is very soluble in sea water. Therefor the ocean can outgas a lot of CO2 but not much O2. In addition, since the amount of CO2 in the atmosphere is small relative to oxygen, releasing the same amount of both gases would substantially raise CO2 while leaving O2 essentially unaffected. A person with your level of understanding of science should refrain from speculating about changes in the climate and atmosphere on a science blog.
  49. Ice data made cooler
    The relative important of various feedbacks the magnify the NH milankovic cycle is still significant area of research as far as I know. The lack of land in SH temperature zone has to involved to explain why there global glacial cycle isnt a seesaw between NH and SH. Beside ocean feedbacks, there is of course albedo (limited in SH because little land available to cover with ice. Australia is too low and too far north) but also note the biogenic methane is clearly a feedback. Swamp methane,(increases with warm, decrease with cold) which then oxidises to CO2. The effect of vegetative change on the CO2 feedback also appears to be significant(see Kohler et al
  50. Models are unreliable
    Chris, first note that models are scenarios based on amount of GHG in the atmosphere. ie if CO2 is 450ppm, then climate looks like x. Now if against all paleo icecore data we have situation whereby warming world REDUCED pulls more CO2 from atmosphere than a cooler one, the result would be that the emissions scenarios need revised. ie for a given rate of fossil fuel consumption, then the rate of accumulation of CO2 in the atmosphere would reduce. However,I am unaware of any modern or paleo data to support the idea that increased temperature would decrease CO2 - in fact all of the evidence I have seen to date shows the opposite.

Prev  2029  2030  2031  2032  2033  2034  2035  2036  2037  2038  2039  2040  2041  2042  2043  2044  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us