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  2051  2052  2053  2054  2055  2056  2057  2058  2059  2060  2061  2062  2063  2064  2065  2066  Next

Comments 102901 to 102950:

  1. Renewable Baseload Energy
    actually thoughtfull, More's Law does not apply. These are very high cost systems with long life times and so turn over and learning takes decades. The costs you quoted for energy for wind and unprintable are not comparable. Not printable is baseload and dispatchable (meaning it can be called up any time as needed by the energy market operator). That is not the case for wind. Here is a rough comparison on an equal basis: http://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108 The "Zero Carbon Australia - Stationary Energy Plan - Critique" provides a more thorough comparison. Grid storage is not unexplored. It is simply totally un economic. The link above covers this too. Placing a link between unprintable electricity generation technology and weapons is a furphy. Sorry. Waste of time even discussing it. Go to BraveNewClimate if you want to discuss that. "I think the short term answer is you have to do both (ANYTHING to get us off of coal!) - but this rational person is putting his long terms bets on technology that improves over time." Why would you bet on something that has low energy density (much lower than fossil fuels) and is not viable now and never likely to be? Why not bet on the technology that has 20,000 time higher energy density, is proven, and has been proven for 50 odd years? Why delay any longer. Saying "I am prepared to accept unprintable will have a role but I want to put my efforts into renewables" is in reality just a way to continue to block unprintable. This is what has been happening for the past 40 years. When I see this sort of argument, I believe the people pushing it, and pushing CAGW, are not serious about CAGW. They are more interested in pushing their beliefs. You talk about doubling. Have you thought of applying the same logic to unprintable. For 40 years development has been blocked in the western democracies. We are still using the technology that uses only 1% of the available energy in the fuel. Consider why you really prefer renewables. Is it rational or emotional? I know the answer, but can you recognise it?
    Moderator Response: [Daniel Bailey] For posterity, please define what it is you mean by CAGW. Thanks!
  2. Climate's changed before
    Try this page . Some good stuff to start you off and some links that might help.
    Moderator Response: Indeed, that is probably the best place for any further discussion of positive feedbacks and "runaway" warming.
  3. Climate's changed before
    Re: reluctant skeptic (141) I've posted the answers to your questions over here where I first saw them. To make things easier, when you have questions, please use the search feature in the upper left portion of any page here. This will give you a narrowed choice of where to post your question. Just pick the one that seems most appropriate & post it there. If multiple questions, follow this procedure for each. It'll get easier the more you do it. The Yooper
  4. Stratospheric Cooling and Tropospheric Warming
    Interestingly, the article by the German scientist is what drove me crazy. He correctly explains why cooling of the stratosphere takes place and explains that heat is trapped in the troposphere. This is correct but suppose the CO2 level were to miraculously stabilize at 390 ppm. The earth would continue to heat up until the IR leaving the troposphere into the stratosphere was the same as before all this started. This has to be because of conservation of energy. The total solar energy coming into the troposphere from the sun must equal the total IR energy leaving the troposphere in the steady state. I asked the question "Why wouldn't the temperature of the stratosphere go back to what it was originally since the same amount of IR energy is leaving. The German scientist doesn't address this. The reason that it doesn't go back to the original temperature is that there is now more IR energy in the atmospheric window and less in the absorption band and only the energy in the absorption band can can react with the CO2 in the stratosphere and the absorption of IR by CO2 is what heats up the stratosphere. Less absorption means a lower temperature permanently. By the way, I wasn't concerned about the cooling due to thinning of the ozone layer because that is easy to understand. It's much more difficult to understand how CO2 causes cooling of the stratosphere. Is this making sense? I'm already thinking about revising this post into two very distinct parts. First, the steady state solution which my post addresses and second, getting to that steady state solution which I'm talking about here. Bob
  5. Stratospheric Cooling and Tropospheric Warming
    Re: reluctant skeptic (4)
    "Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again?"
     Off-topic, but deserving of an answer. Just ran across this brief, but apt, summary from Bob (Sphaerica) over on RC. Check it out. As far as the runaway effect, see here. As far as heading back to another ice age:
    "Our research shows why atmospheric CO2 will not return to pre-industrial levels after we stop burning fossil fuels. It shows that it if we use up all known fossil fuels it doesn't matter at what rate we burn them. The result would be the same if we burned them at present rates or at more moderate rates; we would still get the same eventual ice-age-prevention result. Ice ages occur around every 100,000 years as the pattern of Earth's orbit alters over time. Changes in the way the sun strikes the Earth allows for the growth of ice caps, plunging the Earth into an ice age. But it is not only variations in received sunlight that determine the descent into an ice age; levels of atmospheric CO2 are also important. Humanity has to date burnt about 300 Gt C of fossil fuels. This work suggests that even if only 1000 Gt C (gigatonnes of carbon) are eventually burnt (out of total reserves of about 4000 Gt C) then it is likely that the next ice age will be skipped. Burning all recoverable fossil fuels could lead to avoidance of the next five ice ages."
     Source here [Sorry, Bob, for going so far OT] The Yooper
  6. Stratospheric Cooling and Tropospheric Warming
    Bob Thermal energy flows are determined by temperature gradients. In the atmosphere there are two sinks that collect the aforesaid flows to radiate them to space: the tropopause and the mesopause. If the atmosphere has to dispose of more energy it will have to increase the temperature of its sinks. Then no cooling of the stratosphere but warming of tropopause/mesopause and drop of the lapses rates in the whole atmosphere.
  7. A basic overview of Antarctic ice
    72 Albatross You still prefer to ignore the V09 data and snipe instead?
  8. Renewable Baseload Energy
    actually thoughtfull - Can you repost that link to the cost estimates?
  9. actually thoughtful at 17:18 PM on 1 December 2010
    Renewable Baseload Energy
    Peter Lang: "One problem is that many people have very little understanding of economics, costs, financing. It is impossible to have a rational discussion with people who want to talk about their beliefs and hopes but cannot or will not consider the cost of what they advocate." This is very true. But either side can make this case - I would argue the renewable folks have the better case. I presented DOE/EIA data that showed wind, coal and gas all between US$53 and US$55/unit, the unmentionable at $60/unit and solar PV at $100/unit (best current case). CSP was not in that particular analysis, but usually weighs in roughly equal to wind. We also have a "Moore's law" type phenomena where the more PV and CSP you do, the cheaper it gets (there will be limits to this). We also have the fact that grid storage remains unexplored. Pilot projects have already been successful (as opposed to "clean coal" - which doesn't exist anywhere, for any amount of money, on planet earth). Do you bet on the known technology with huge negatives (as we spend the weekend contemplating a rehash of the Korean war, only this time with nuclear weapons)? Or do we look ahead to different, better technology? I think the short term answer is you have to do both (ANYTHING to get us off of coal!) - but this rational person is putting his long terms bets on technology that improves over time. Or maybe you would be willing to give me a penny today, and then double it tomorrow, repeat each day for one year? How about for one month? (a month would only be 5.3 MILLION dollars!). The power of compound efficiency increases/cost reductions swings this one way in favor of renewables. And the real world experience of PV, CSP and wind prove this is no pie-in-the-sky, but our best possible future (OK, with a helping of the unmentionable power as well).
  10. Stratospheric Cooling and Tropospheric Warming
    It's late at night and so much has been mentioned above but other things do cause cooling. The ozone layer has thinned out and ozone absorbs incoming solar energy which causes the stratosphere to warm up. As I understand it, ozone is responsible for the stratosphere and for the temperature inversion of the stratosphere. Since there is less ozone, less incoming solar radiation is being absorbed. Less solar energy being absorbed means that it is cooler. As I understand Venus, the runaway greenhouse effect on Venus was caused by evaporation of water. The sun then broke the water molecules apart and the hydrogen escaped into space. So the water is gone forever. I believe that CO2 was a feedback as it has been on earth for the past million or so years. Of course the contrarians use this to imply that CO2 is not a problem. This cannot happen on earth because earth's atmosphere is sufficiently cool such that water vapor condenses and rains back to earth. I'm saying a lot here but I must stress that I am very much an amateur at this and may not be totally correct. I'm also a bit tired and may not be writing very clearly. Bob
  11. Renewable Baseload Energy
    Bern, If we ignore cost, I guess anything is "possible". But I doubt you could get more than about 1 to 5% firm power if you had wind farms spread all over Australia. The problem is that the wind just doesn't blow much in the places where wind farms are not being built. Furthermore, the cot of transmission alone would be many time higher than the cost of simply using the unprintable technology. It is just plain silly. Regarding cost benefit of emissions reductions, the externality costs per MWh are included in the ExternE link I provided up thread. Numbers like $1,240 trillion are meaningless and probably come from a 'biased' researcher anyway. I wonder if this estimate of cost benefit may not be more realistic: http://johnhumphreys.com.au/2010/06/05/benefit-cost-analysis-for-the-ets/ What it really boils down to is that we should aim to cut emissions in the least cost way. If we keep hammering renewables and being anti-(unprintable), the vast majority of middle people are going to question the veracity of everything being advocated. Being economically irrational about how to cut emissions leads to questions about how rational and objective is the rest of the stuff being advocated by the groups with the same leanings. One doubt leads to another.
  12. A basic overview of Antarctic ice
    Daniel @75, To take your metaphor further, I heard someone the other day say that "skeptics" are now scraping the rust off the bottom of the barrel.
  13. A basic overview of Antarctic ice
    Thanks, Albatross! BTW, it appears the level of replies to a 'basic overview' have gotten pretty in-depth. It seems da bottom of da barrel is now being scraped, eh? (yes, that's UP humor) The Yooper
  14. Renewable Baseload Energy
    Peter Lang - Even on a quick read, the critiques do have some serious points. The ZCA proposal seems to grossly underestimate power demands (it will take quite some time and regulatory/pricing impetus to change heating/cooling methods), transportation energy needs, and quite possibly the build costs of the solar plants. The ZCA schedule is completely unreasonable, but that's not as much of a cost issue. I found the wind comments a little thinner - there's certainly a decent amount of 1.4-1.5MW generator costing available for consideration - but still a ZCA underestimate. On the other hand, having looked at references such as Czisch (have you read this?), studying power availability using a large catchment basin, I think the wind availability numbers are really low. Not enough to overcome the optimism of the ZCA proposal, but still an underestimate. As Bern noted, renewables do appear to be able to supply baseline power, albeit at what may be a higher cost. Of course, business as usual will have an extremely high cost too, just not in terms of energy...
  15. Climate's changed before
    Sorry, this is a repeat of a post today, which I should have included with this topic, but placed under stratospheric cooling. My first blog--I haven't found such an interesting site before. I have reviewed some old posts and found one under "climate's changed before" with a question that I have also wondered, from jebjones42. It did not seem to have been addressed in any subsequent posts. "I'm curious. Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again? Clearly, despite CO2 having a positive feedback loop, we didn't get runaway warming. We're not living on Venus. Even if we're headed for higher temps, rising sea levels, drought, mass extinctions, catastrophic loss of human life, etc. At some point won't it top out an head back to another ice age? What's prevented a runaway greenhouse effect in the past?" I am also interested in this question. Is it sun cycles and precession/sun obliquity, and is the prevailing thought that we will overwhelm these historical cyclical temp. changes ?
  16. Renewable Baseload Energy
    I'd go with KR's comment at #193, about the wind farms all being in the same wind pattern. If you look at the locations of the windfarms on that Landscape Guardians site (thanks for that link, Peter Lang!), you'll see that they're all on the south-east coast of Australia, and are all sited to pick up the winds coming off the southern ocean. Great place to put a wind farm, if you get paid a fixed amount per kWh irrespective of when it's produced. Not so great to put them all there if you're interested in producing something closer to a base-load profile - the correlation between sites along the southern coast of Australia is often going to be very positive, and dependent almost entirely upon the weather patterns at the time. On the other hand, that's where the greatest wind resource is, so a means of storing that power (or having fast-reacting backup that can fill in the gaps) would be great. As I understand it, that's more-or-less what the ZCA people are proposing with their solar thermal with storage. Cost is a different issue - and, while an important consideration as to whether 100% renewables is the way to go, it doesn't actually affect the question of whether renewables are *capable* of providing baseload. The answer to that question seems to be "yes". It may be very expensive to do so, and we may be far better off with a large contribution by nuclear, but just because it might be unacceptably expensive doesn't mean it's not possible. :-D BTW, I read an old post on Climate Progress earlier, linking to a study suggesting the annual cost due to climate change effects of "business as usual" will be something around $1.5 trillion by the middle of the century. Net present value of the next 80 years worth of climate change costs was something like $1,240 trillion. Scary numbers.
  17. Stratospheric Cooling and Tropospheric Warming
    This is a tough problem that I have long struggled to grasp and I thank you for trying to explain it and for provoking me to think about it some more. However, I can't help thinking that your model is a bit too simple to allow you to conclude that increasing CO2 is the only possible mechanism to explain stratospheric cooling. For one thing, I'm not sure that there even would be a stratosphere (ie with temperatures increasing with height) if there was no oxygen/ozone in the atmosphere as there is in your model. So it may not make sense to talk about a warmer lower atmosphere causing an even cooler upper atmosphere in such a simplified case. Also, I understand that other variations, in water vapour, volcanic aerosols, chlorofluorocarbons and methane concentrations, can cause temperature changes in the stratosphere. Having said that, I don't actually doubt that rising CO2 does result in a cooling stratosphere, I'm just struggling to understand how exactly and by how much. There's a helpful article by some German scientists here: They conclude: We now know that stratospheric cooling and tropospheric warming are intimately connected and that carbon dioxide plays a part in both processes. At present, however, our understanding of stratospheric cooling is not complete and further research has to be done. ....
  18. Stratospheric Cooling and Tropospheric Warming
    This is a nice simple model, explains the absorption for us non-experts. I have reviewed some old posts and found one under "climate's changed before" with a question that I have also wondered, from jebjones42. It did not seem to have been addressed in any subsequent posts. "I'm curious. Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again? Clearly, despite CO2 having a positive feedback loop, we didn't get runaway warming. We're not living on Venus. Even if we're headed for higher temps, rising sea levels, drought, mass extinctions, catastrophic loss of human life, etc. At some point won't it top out an head back to another ice age? What's prevented a runaway greenhouse effect in the past?" I am also interested in this question. Is it sun cycles and precession/sun obliquity, and is the prevailing thought that we will overwhelm these historical cyclical temp. changes ? I apologize if I am posting this in the wrong place. I am new to blogging.
  19. Renewable Baseload Energy
    Peter Lang - I'm still running the numbers from the critiques, I'll comment when I have a better feel for them. As to site placement, unless there is large scale (national) oversight, I suspect that the individual power companies will not chose the best mix of sites, but rather load sites to the highest wind levels regardless of large scale correlation.
  20. Renewable Baseload Energy
    KR, You say "But even if the costs are off by a factor of two, even if the energy requirements are off by a factor of two." You clearly did not read the critique or else you did not understand it.
  21. Renewable Baseload Energy
    KR, If you are not prepared to look at the links that have been suggested to you, then there is little point in the discussion. The points you are making have been covvered manny many times elsewhere. None of it is new.
  22. Renewable Baseload Energy
    Peter Lang - Looking at Quokka's links, the proposal discussed includes 60% concentrating solar and 40% wind. This is already reducing correlation considerably. I'll also note that this proposal (I'm sure it's optimistic, no worries about that) estimates that when global concentrating solar (CSP) reaches 8-9GW the costs will drop below coal energy costs. This proposal alone has 42GW of CSP. The timeline critiques are quite reasonable - I cannot see action occurring on that schedule. But even if the costs are off by a factor of two, even if the energy requirements are off by a factor of two - this is one potential approach to reducing CO2 consumption.
  23. A basic overview of Antarctic ice
    Hi all, OK, so I have been to the NSIDC FTP site and downloaded some data for sea ice area over the Arctic and Antarctic for January and February (peak of Austral summer) and July through September (Boreal summer) for all years between 1979 and 2010. Daniel and Tamino have also looked at this, but since HR wants us all to be critical ;) Great post Daniel by the way. Some things to note off the bat-- nobody is dismissing the presence of Antarctic sea ice during the austral summer. What I think people have been unsuccessfully trying to communicate to the "skeptics"/contrarians here is the significance of the difference in the rate of change in the sea ice extent. The distribution of land mass is also important, but more about that later. Some numbers: In the Arctic in August and September the rate of loss has accelerated in recent years-- in fact, a quadratic fit provides a much superior fit to the data for July and August and September. But for ease of comparison I will refer only to trends derived using an OLS model. Here statistically significant is set at 95% (p-value < 0.05). Arctic sea ice area trends 1979-2010: January: about -37 000 km/decade (not statistically significant) February: about -34 000 km/decade (not statistically significant) July: about -330 000 km/decade (statistically significant, p-value = 0.000) August: about -390 000 km/decade (statistically significant, p-val =0.000) September: -429 000 km km/decade (statistically significant, p-val =0.000) Antarctic sea ice are trends 1979-2010: January: about +74 000 km/decade (not statistically significant, p-value = 0.219) February: about +75 000 km/decade (not statistically significant, p-value = 0.132) July: about +158 000 km/decade statistically significant, p-value = 0.02) August: about +100 000 km/decade (not statistically significant, p-val =0.072) September: about +100 000 km km/decade (not statistically significant, p-val =0.117) So hopefully this clarifies the point that Robert and others have been trying in vain to make-- the statistically significant and accelerating rate of loss of sea ice during the boreal summer far exceeds the small (statistically insignificant) increase of sea ice during the austral summer. During the boreal summer, the minimum Arctic sea ice area is currently around 3.2 million km^2, compared to 4.5 million km^2 in the early eighties (down 1.3 million km^2). By comparison, the Antarctic sea area minimum during the austral summer is currently around 2 million km^2, compared to 1.8 million km^2 in the early eighties (up 0.2 million km^2 and that trend is not statistically significant). Another issue that I alluded to earlier (here, but I was clearly being too subtle) is that the Arctic ocean is essentially surrounded by a continental land mass which heats up rapidly during the summer. In contrast, the Antarctic ice sheet is thousands of metres high and surrounded by a band of very strong westerlies which essentially isolate it. That is why, for now at least, there has been little polar amplification over most of the Antarctic (not to mention the complicating factor of ozone loss). In contrast, in part because of the albedo feedback, there has been very marked polar amplification of the Arctic. The loss of sea ice from the Arctic during the boreal summer is easily offsetting any gains in the Antarctic sea ice during the austral summer. It will be interesting to see how long it takes before the Antarctic sea ice starts responding to the warming en mass, right now decreases have mostly been regional.
  24. Renewable Baseload Energy
    KR, The best wind sites are selected. All of what you are talking about is well known. The investors and the regulator want the best sites. But I suggest you take a look at the costs. You cannot deal with this in the absence of cost. That is the crunch. One problem is that many people have very little understanding of economics, costs, financing. It is impossible to have a rational discussion with people who want to talk about their beliefs and hopes but cannot ore will not consider the cost of what they advocate.
  25. Renewable Baseload Energy
    Ogemaniac, "Economically competitive vs what? Subsidized-up-the-ying-yang fossil fuels, whose free public garbage dumping rights alone are worth something on the order of a trillion dollar per year?" It is renewables that are "Subsidized-up-the-ying-yang". Try putting properly comparable figures on your assertions (per $/MWh; even better, take it a step further and provide $/MWh of energy that meets our demand for power quality). Regarding the cost of externailites, why don't you provide actual figures instead of adjectives. Read this and get a handle on the actual value of externalities: http://www.externe.info/externpr.pdf Look at the tables at the top and bottom of page 13. The point is that even when the externailities are included, renewables are still many times higher cost that fossil fuels or the other (unmentionable) baseload electricity generation technology. You should also taske into consideration what is the real cost to society of higher cost energy. Have a long hard think about that!!
  26. Renewable Baseload Energy
    Peter Lang - I would be very interested in a wind correlation study for Australia. That would prove or disprove any possibility of reliable power by splitting generation between different regions. Not knowing Australian wind patterns, might it possible that this region is covered by the same strong trade winds? The study I referred to here indicated correlations as low as 0.3 for Australian sites only 375km separation (small by the measures proposed) - if you chose sites in different wind patterns.
  27. Renewable Baseload Energy
    KR, You said: "First, what you want is negative correlation between wind sites." I agree. But that is not what happens in practice over areas of over a thousand km east west as is demonstrated in the Australian National Grid and other large grids. @ 184 I said: "This grid demonstrates high correlation of wind power output." That is, high positive correlation, the opposite of high negative correlation. I thought I was sufficently clear. Solar and wind cannot provide baseload generation at a cost that is anywhhere near viable. Furthermore, they are unlikely to ever be the case. US DOE hasd a goal for solar thermal with energy storage to be able to provide "baseload" generation by 2030. But the costs would appear to be enormous. The costs of providing 24 hour power (as long as there is not more than 1 day of overcast weather in a row and no dust storms) are reasonably estimated in Quokka's first link in post #175.
  28. A basic overview of Antarctic ice
    #70: "Bad data analysis is ..." Here are some key points about the data analysis in Velicogna: For both the Greenland and Antarctica ice sheets, we found that Radj^2 is larger when we use a quadratic fit, i.e., the data are better modeled by a linear increase in mass loss than with a constant mass loss. To verify that the improvement obtained with the quadratic model is significant we used an F-test. The F-test show that the improvement obtained with the quadratic fit is statistical significant at a very high confidence level (99%). Note that if we use the unfiltered GRACE time series instead of the smoothed one, the Radj^2 values drop by 2% and 16% for Greenland and Antarctica, respectively. This illustrates the importance of removing the seasonal variability in the trend estimates. The improvement is much larger for Antarctica than for Greenland. So it doesn't sound 'bad'. But I guess I would accept HR's nitpick: Why wasn't the quadratic function used shown in the paper? That way the 'acceleration' could be determined directly. But here is some 'hedging': The Antarctic filtered data also suggest a slight change in trend around the end of year 2006. It appears that the long term variability could be described by two linear trends, one for the period 2002–2006 and the second during 2006–2009. ... We fitted two straight continuous lines through the data, i.e., connected in the middle. We find that the Radj^2 for the two lines regression model is 0.97, the same than for the quadratic model So to answer HR in #55: It appears that breaking the data into two segments is not arbitrary, nor is it necessarily 'bad'. My key take-away: GRACE supports a flat rejection of the skeptic claim that Antarctica is gaining ice.
  29. The Inconvenient Skeptic at 15:01 PM on 1 December 2010
    Stratospheric Cooling and Tropospheric Warming
    Bob, I agree in keeping it simple for this. It would be interesting to see what would happen with the temperature profile with the model. I tinkered with the one in the link and didn't see anything that would generate a temp profile as a response. I am curious about the convection only model. Nitrogen would have to dissipate heat at the top, but I am curious as the method. Say a planet with nitrogen density comparable to Venus. What would happen there? I don't know, but I am thinking about that model. That is why I ask. Hope to see more like this one.
  30. A basic overview of Antarctic ice
    HR, yes, at least we can agree that your analysis of the V09 data is a distraction.
  31. A basic overview of Antarctic ice
    HumanityRules: Rather than trying to get to the heart of "skeptics" mental state why not try looking at the data critically. The comment you objected to wasn't directed at you specifically. Sorry that wasn't clear. As for your other comment, I've been looking at the data critically since the late 1980s. Please don't make the mistake of assuming that people have not been critical until they've embraced whatever species of "skepticism" you favor.
  32. Stratospheric Cooling and Tropospheric Warming
    Thanks John, It is a completely artificial and impossible situation. However, my objective was to make it understandable and to do that I had to keep it very simple. Also, the nitrogen is not necessary. People understand parts per million but the concept of an equivalent CO2 vapor pressure to that of 100 ppm and 1000 ppm would have made it more complicated. I read other explanations on the Internet explaining this but I could not understand any of them. It drove me crazy and then I had one of those Eureka moments when I realized what was going on. It is really not explainable without considering the absorption spectrum. I suppose for simplicity, I cannot allow convective transfer:):) Bob
  33. The Inconvenient Skeptic at 14:31 PM on 1 December 2010
    Stratospheric Cooling and Tropospheric Warming
    Nice article here. I have been looking at this issue as well recently. One thing I would argue is that the tropopause would be much less defined (or possibly not exist) in this situation. The tropopause on Earth is impacted by water vapor and in this case water vapor would not be an issue. As the density of the atmosphere dropped, less energy would be needed to cause a comparable amount of temperature increase. I really don't see how the tropopause would develop in this situation unless full saturation was reached. It is an interesting situation. Also. Curious if you have run a model with just nitrogen. The atmosphere would warm from convective transfer, but after that the model gets odd and I am still sorting through it. This is fun science. John Kehr The Inconvenient Skeptic
  34. Twice as much Canada, same warming climate
    GC - me too.
  35. Renewable Baseload Energy
    "The point of this post, that renewables can provide base load energy, is true. However, it is NOT accurate to claim that renewables can provide economically competitive base load energy" Economically competitive vs what? Subsidized-up-the-ying-yang fossil fuels, whose free public garbage dumping rights alone are worth something on the order of a trillion dollar per year?
  36. A basic overview of Antarctic ice
    #69 muon Thanks for playing. I acknowledged later my data presentation was a distraction from V09 data but I don't think it really matters because as you say it's all about trends. So please stay with V09's original data. It's not just about whether there is a downward trend it's about whether there is an acceleration in that trend. I think V09 (along with Rignot 2008a) appear on the surface to be the strongest supporting data for that outlook based on the Copenhagen Diagnosis figure. So the blip matters here. Look I have to disagree with your final paragraph. Bad data analysis is bad data analysis. There's no running away from that, no matter how inconsequential you think it is.
  37. Twice as much Canada, same warming climate
    Re: gallopingcamel (73) Let me know or send me a link. I'd be interested in hearing your ideas on those topics. Thanks! The Yooper
  38. gallopingcamel at 13:30 PM on 1 December 2010
    Twice as much Canada, same warming climate
    Daniel Bailey, Thanks for your comment. This is a great blog as it does not censor non-conformists (such as camels and BPs). I visited NOAA in Asheville; the most senior person I met was Tom Peterson. What he told me was "very enlightening" and I am still trying to digest it all, especially climate change at high latitudes such as Greenland and arctic Canada. I hope to have my ideas organized in a few weeks with the idea of posting them on "Digging in the Clay".
  39. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel, people have asked you, repeatedly, the simple and essential question "What happens to the photons from sources cooler than the target?" You have ignored those repeated questions, despite them being at the heart of the topic of this thread. Please answer my most recent version of that question: What happens to the photon named Greg?
  40. A basic overview of Antarctic ice
    #67: "nobody has even acknowledged whether they see that short-lived upturn around 2006." HR, I'll play. I see it! And I acknowledge it appears just as you describe: 'a short-lived upturn'. Unfortunately, your graph in #55 is in 'sea level equivalents (cm) anomalies', so there's some appling and oranging going on. However, this blip does not eclipse the downward trend, which is present no matter how you slice and dice these data. Trends, its all about trends. Agnostic at #43 made it quite clear that this is one complicated subject and we're trying to sum it up with one number. It's a bit like a conversation that someone might have over whether the stuff in their freezer is thawing evenly -- while their house burns down.
  41. A basic overview of Antarctic ice
    Re: Steve L (26, 28, 65) Sorry I missed your earlier questions! You are correct in that austral summer solstice is important (due to the sun being the highest above the horizon at that point), but remember that summer minimum ice extent is also important, as even low-angle sun hitting open water late in the melt season still gets absorbed, contributing to warming. As you noted, this then contributes in the Arctic to an extension of the fall melt season (the fact that melt there is now actually lasting into fall is remarkable). In fact, Arctic area and extent have declined in every month: and ice-edge latitude has moved poleward as well: The money shot for the Antarctic is this: poleward retreat of sea ice goes only so far. The continent, with its lofty elevation and citadel of cold (buttressed by the ozone-hole-strengthened circumpolar vortex) is relatively immune for now to the summer suns' direct effects. The Arctic has no such reinforcements at its back. Latitudinal retreat will continue until the pole is reached, and summer ice known to millennia of mankind will be no more. Cryosat-2 data will provide definitive data on Arctic ice mass & will be the final (until we get something better) arbiter for ice data for both poles. Per Tamino's post, Antarctic summer ice minima increase is not statistically significant. When the Southern Ocean warms enough, then we will see an early and longer melt season in the Antarctic (with trends growing similar to those I showed you for the Arctic). Which is bad news for the WAIS in general and the PIG in specific... Thanks for reminding me about Tamino's post! The Yooper
  42. A basic overview of Antarctic ice
    64 Philippe Chantreau My point hasn't got as far as the wider perspective on the subject. It's specifically about the way the data is used in Velicogna 2009. If data is used badly in making an argument there is no defense for that work in the fact that it is in agreement with other studies. I don't disagree with your general argument that there is strength in independant well crafted analysis supporting a particular interpretation. My question is whether we have that in the first place. I'm still looking for a bold defence of V09's method of data analysis given that I recognise important variablity in the data. Of the few people who've responded to my post nobody has even acknowledged whether they see that short-lived upturn around 2006. Philippe please have a go at critiquing my specific criticisms of the data, I'm happy to discuss the merits of mutaully supporting evidence after I've got over the hurdle of whether the V09 estimates are meaningful.
  43. A basic overview of Antarctic ice
    HumanityRules, Perhaps the reason Velicogna uses 2006 as a start date is because the rate of ice loss after 2006 was greater and because Rignot et al. 2008 a,b measured accelerations in glaciers for sure between 2006 and 2007. I also noticed that you have yet to address the issue that multiple methods are supporting the same answer. It is because of the aforementioned uncertainties that we should look for independent measurements in agreement. That is the crux of science. We acknowledge there is the potential for error in analyis but when we see it repeated with similar conclusions and different methods then we conclude that there is a foundation upon which claims can be built.
  44. Renewable Baseload Energy
    An Australian study (very small) on wind speed correlations: Gloor 2010 "Due consideration must be given to local conditions when assessing these correlations. Take Carnarvon and Geraldton for example. Though they are fairly distant from each other (446 km) they show a strong correlation (0.47) as they are in the same wind conditions of the Trade Winds that blow constantly and consistently over a wide area. So wind farms in Carnarvon and Geraldton would tend to go offline at the same time despite being quite well separated in distance. Contrast this with Perth Metro to Albany. Albany is in the southern ocean wind pattern, well out of the trade winds and has a lower correlation (0.33) with Perth Metro despite being only (375km) distant. So wind farms in Albany could continue to provide power to Perth when the wind farms around Perth would be at low output potentially. This is taking advantage of the different wind regimes. ... The graph of correlation with distance for these datasets does show a decreasing correlation with increasing distance however the spread of data is quite large. There is not a neat line of decreasing correlation but more a broad range. However it does support the idea that widely spread wind farms, taking into account the wind regimes of the sites, can be less correlated than closely spaced wind farms. If the correlation relationship held up then these wind farms, if connected together, could perhaps provide more reliable power than a single wind farm or group of closely grouped wind farms."
  45. Renewable Baseload Energy
    Peter Lang - First, what you want is negative correlation between wind sites. If you use sites with negative correlations, when the wind dies at one site it's high at another - say sites on opposite sides of the country. And using a mix of renewables (solar and wind) reduces correlation of down times even more. Second, you are once again focusing on a single area of Australia, the South-East. As I stated in an earlier discussion, widely separated sites are required. I don't know the details of Australian wind samples, it may not be possible to get sufficient negative correlation to supply significant baseline. On the other hand, it quite possibly may. It certainly seems possible in Europe, but again I don't have detailed multi-site wind/sun surveys with correlations in Australia. Third, with sufficient negatively correlated sites, base capacity, and storage, your argument that wind farm backups would burn more gas than straight non-stop natural gas turbines is, frankly, simply ridiculous. That requires near-constant use of the turbines with stop/start cycle energy outweighing the time off due to wind input - and with uncorrelated sites and storage, that's not going to be the case. Personally, I consider Masterresource a strongly biased and poor source (like WUWT) - I would prefer seeing calculations by someone without an axe to grind. The article you pointed out on baseline requirements is interesting - instant loads covered by generators, intermediate by gas turbines. Solar cannot cover the 'generator spin' loads, although wind can. There are certainly some points worth considering there, points directly related to renewables. I would strongly suggest (Moderators - opinions?) that any discussion of nuclear energy pros and cons remain on What should we do about climate change?, where that has been hashed out over 379 comments to date. Please do not hijack this thread.
    Moderator Response: [Daniel Bailey] Agreed. This thread is about Renewable Baseload Energy. Comments about nuclear energy are off-topic here, and should more appropriately be posted on the What-should-we-do-about-climate-change thread. Thank you all in advance.
  46. A basic overview of Antarctic ice
    Re #62 & 63, I posted comments similar to what Bill wrote here (see #26 and 38). My comments were ignored. :( DB(Yooper) -- the fact that Antarctic sea ice melts back to the continent by the end of the austral summer does not contradict the fact that there is sea ice there during the austral summer solstice. Cryosphere today says the current sea ice area there is 10.9 million sq km. There will still be millions on December 21 and even January 21. There could be as much as a half million sq km more ice than the 1979-2008 average over that time period (currently 0.3 million sq km). This anomaly in reflective area may not be as great as is observed in the Arctic during the boreal summer solstice (can someone check?), but we shouldn't pretend that it doesn't exist.
  47. Renewable Baseload Energy
    Rob Honeycutt, Have you heard of the Pareto Principle. One application is to put most of your effort into what can have the largest effect. Non hydro renewables may provide 10% of future power supply - perhaps. Nuclear and pumped hydro can provide 100% now. It has been doing nearly that for the past 30 odd years in France and providing low cost electricity as well. We have a proven way to cut emissions at low cost. Why waste any more time chasing the renewable dream. @180 last paragraph you put out the often stated argument which in effect is "I am not against nuclear, but renewables will be part of the solution so let's focus on them". This has been going on for 20 years in Australia so no one is prepared to remove the impediments to nuclear in Australia. We need to put our main effort where we can get the biggest gains. That is on nuclear. So I'd urge all those who want to cut emissions to put their efforts into changing the opinions of the anti-nukes - the environmental NGOs, media (especially ABC), and the politicians. It is far more important, and urgent, to remove the impediments to nuclear than it is to implement a carbon price. Once a carbon price is implemented then the many impediments to nuclear and favouritism for fossil fuels and renewables will be very hard to remove. We need to focus first on removing the impediments to nuclear.
  48. Renewable Baseload Energy
    Rob Honeycutt, Investor dollars are being poured into renewables because the government is mandating them and subsidising them. Wind power is subsidised by about 100% to 150% and solar by about 1000%. The investors are guaranteed the income from government and consumers for 20 years. Under such conditions of course investors will invest. The point I'd make is, people contributing on Skeptical Science think they can do objective research. But just wishing and wanting is not going to make renewables viable. They are not viable and probably never can be (at more than about 10% of the total generation). There is far too much to explain in the comments field. I'd urge those that are seriously interested to actually read the links from people in the industry, not just the renewable energy advocates. The anti nuclear protesters over the past 40 years (the same people as the renewable energy advocates), by blocking nuclear have caused CO2 emissions to be about 20% higher now than they would have been if the development of nuclear power had been allowed to progress in the Western democracies over the past 40 years. Not only are emissions 20% higher now than they could and should have been but they will remain much higher for many decades because the development process was stalled and it will take decades to recover to catch up. That is what irrational advocacy does. So, I urge you that think you can do objective research to start informing yourselves. Look beyond the spin propagated by the so called environmental NGO's like Greenpeace, WWF, FoE, and the Australian Conservation Foundation.
  49. Renewable Baseload Energy
    KR, There is another really important point to understand. The claims about how much CO2 emissions are avoided by wind farms are bogus. It seems that wind farms avoid littel if any CO2 emissions and can actually cause more emissions than if there is no wind in the system. This explains: http://www.masterresource.org/2010/06/subsidizing-co2-emissions/
  50. Renewable Baseload Energy
    KR, To see the positive correlation across the Australian NEM wind farms look at the charts for - August 2010 (seven cycles of power output from 20% to 80% of capacity), http://windfarmperformance.info/documents/analysis/monthly/aemo_wind_201008_hhour.pdf - May 2010 (Capacity factor averaged less than 5% for a week and was negative on 65 5-minute intervals during that week) http://windfarmperformance.info/documents/analysis/monthly/aemo_wind_201005_hhour.pdf To get the data: http://www.landscapeguardians.org.au/data/aemo/

Prev  2051  2052  2053  2054  2055  2056  2057  2058  2059  2060  2061  2062  2063  2064  2065  2066  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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