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Post by richdo on Apr 12, 2009 0:27:44 GMT
...and this just in from Mauna Lao... ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txtmeasured CO2 conc. hits another "all time record high" for this data set. Coming in at an avg (seasonally corrected) for the month of March 2009 at 387.24 ppm So the divergence with temperature and CO2 continues to widen. ?
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Post by steve on Apr 13, 2009 17:49:47 GMT
3. Well, CO2 mitigation will help solve the global energy imbalance too. What imbalance are you talking about? I just used gridley's word. I assumed he was referring to the fact that our energy usage may be growing faster than new sources of energy are arriving.
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Post by steve on Apr 13, 2009 18:09:55 GMT
I think you make good points. The key flaws in what you say are these: 1. Even though the model projections are flawed (yes I admit that), we have the basic physics that says CO2 causes warming all else being equal. We also have observational evidence that feedbacks to warming are positive - the evidence is by far from being wholly model-based. 2. The costs of mitigation are, I think, deliberately overstated. Our economy changes radically year on year, so arguments stating that "business as usual" is the only way to go are flawed (particularly in the current environment); there will be business advantages that arise from whatever method of carbon pricing evolves. If it improves capital flows towards energy efficiency, renewable energy and so forth we can start the long job of putting human civilisation on a footing for a post-oil future. 3. The reason we got hit by a truck was because we borrowed too much money from China to buy consumer crap from China. Yes it was nice to have, but Western civilisation would have survived just fine even if it had had to wait an extra couple of years for the latest Ipod. I see no reason why we can't fix the economy *and* tackle energy efficiency at the same time - it's called thrift. Look what trying to avoid the inevitable has done to the US car industry! I accept that all other things being equal, additional CO2 causes some small amount of warming, but I question whether "we have observational evidence that feedbacks to [CO2] warming are positive." 1) You have said that GHG's warm the earth some 30 degrees above what it would be without them. My understanding of GHG theory is that the current concentration of GHG's would warm the earth by a further 30 degrees or so if it weren't for the negative feedback of weather, Ocean Currents, albedo, etc. There isn't a cumulative positive feedback to GHG forcing. This doesn't prove that forcing from additional CO2 does not have a positive feedback, but it does bring it into question. The 30 degree figure is theoretical. Essentially, if you calculate the temperature of the earth from space, you get about 250 Kelvin as you are measuring it based on the temperature of the upper layers of the atmosphere. If you remove the greenhouse gases, you'd be measuring the surface of the earth, and get a temperature of about 280 Kelvin. But at 280 Kelvin, the earth would be emitting far more radiation than it is absorbing, and would therefore want to cool to about 250 Kelvin. Given our limited observations, I'm not really sure whether we know to what degree PDO, ENSO etc actually cool the earth, and to what degree they just cool the atmosphere by bringing cooler water to the surface. If you have references for the above I'd be interested. [/quote] 3) And, if one looks only at the recent years, there is little sign of warming despite the growing CO2 concentration. Again no sign of positive feedback. This is particularly cogent for those who downplay the affect of Ocean Currents on Global Temperatures.[/quote] There is no question that ENSO and PDO can significantly influence atmospheric temperatures. By significantly, I mean larger than the 0.1-0.2C per decade rise expected from CO2 increases. While we are still getting "top ten" warm years despite sustained negative ENSO etc. it would be optimistic to assume warming had gone away. An observationally based estimate of the climate sensitivity JM Gregory, RJ Stouffer, SCB Raper, PA Stott, NA … - Journal of Climate, 2002 ams.allenpress.com/amsonline/?request=get-document&doi=10.1175%2F1520-0442(2002)015%3C3117:AOBEOT%3E2.0.CO%3B2There are also studies based on the size of the ice age cycles that suggest that it is hard to explain the size of the cycles on albedo and CO2/methane effects alone (the Milankovitch cycles don't affect the TSI much).
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Post by gridley on Apr 14, 2009 16:10:34 GMT
What imbalance are you talking about? I just used gridley's word. I assumed he was referring to the fact that our energy usage may be growing faster than new sources of energy are arriving. Yup, imbalances was my word. There are a number of imbalances in our (the human race's) energy use, just look at the electrical power kwh and their source generated by country for one example. Then ask yourself how the rest of the world can achieve energy parity with US (or other 1st world country) energy levels without evil CO2-emitting sources? I really don't see how any CO2 mitigation plan is going to improve the world energy situation, though I'll grant that crippling the US is certainly one way to achieve parity in poverty. Hydro power is great, but opportunities are limited. Nuke is great, but it isn't a bootstrap technology. Fusion is perpetually 10 years away (though I think it may be getting down to perpetually 8 or 9 years away), and isn't a bootstrap tech. Wind, solar, wave... all unreliable (requiring power storage methods), and location limited.
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Post by duwayne on Apr 15, 2009 0:02:50 GMT
Given our limited observations, I'm not really sure whether we know to what degree PDO, ENSO etc actually cool the earth, and to what degree they just cool the atmosphere by bringing cooler water to the surface. If you have references for the above I'd be interested. There is no question that ENSO and PDO can significantly influence atmospheric temperatures. By significantly, I mean larger than the 0.1-0.2C per decade rise expected from CO2 increases. While we are still getting "top ten" warm years despite sustained negative ENSO etc. it would be optimistic to assume warming had gone away. An observationally based estimate of the climate sensitivity JM Gregory, RJ Stouffer, SCB Raper, PA Stott, NA … - Journal of Climate, 2002 ams.allenpress.com/amsonline/?request=get-document&doi=10.1175%2F1520-0442(2002)015%3C3117:AOBEOT%3E2.0.CO%3B2There are also studies based on the size of the ice age cycles that suggest that it is hard to explain the size of the cycles on albedo and CO2/methane effects alone (the Milankovitch cycles don't affect the TSI much). You concur that Ocean Currents have significant impacts on Global Temperatures but for ask refences on "How much?" You probably have seen several articles recently which call for little or no warming during the next 20 years or so because of the expected negative PDO. The magnitude of the PDO forcing would then be at least equal to CO2 and in this instance in the opposite direction. Joseph D' Aleo has published articles which show a good correlation between temperature change and PDO's/AMO's (and almost almost no correlation with CO2). The magnitude can be seen in these correlations. Your reference above on "observationally based estimate of the climate sensitivity" didn't provide any evidence that I could see that there is a positive warming feedback to CO2 forcing. The low end of your expected 0.1 to 0.2C would seem to allow for little or no positive feedback as well. And your comment that it would be"optimistic to assume warming has gone away" doesn't seem to have anything to do with our discussion on feedback or anything I've said. I think we have come a long way from the days of a forcast of warming by the end of this century of 3 to 8C and are approaching the point where there will be general agreement that there is no positive feedback to CO2 forcing.
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Post by steve on Apr 15, 2009 11:59:32 GMT
Given our limited observations, I'm not really sure whether we know to what degree PDO, ENSO etc actually cool the earth, and to what degree they just cool the atmosphere by bringing cooler water to the surface. If you have references for the above I'd be interested. There is no question that ENSO and PDO can significantly influence atmospheric temperatures. By significantly, I mean larger than the 0.1-0.2C per decade rise expected from CO2 increases. While we are still getting "top ten" warm years despite sustained negative ENSO etc. it would be optimistic to assume warming had gone away. An observationally based estimate of the climate sensitivity JM Gregory, RJ Stouffer, SCB Raper, PA Stott, NA … - Journal of Climate, 2002 ams.allenpress.com/amsonline/?request=get-document&doi=10.1175%2F1520-0442(2002)015%3C3117:AOBEOT%3E2.0.CO%3B2There are also studies based on the size of the ice age cycles that suggest that it is hard to explain the size of the cycles on albedo and CO2/methane effects alone (the Milankovitch cycles don't affect the TSI much). You concur that Ocean Currents have significant impacts on Global Temperatures but for ask refences on "How much?" You probably have seen several articles recently which call for little or no warming during the next 20 years or so because of the expected negative PDO. The magnitude of the PDO forcing would then be at least equal to CO2 and in this instance in the opposite direction. Joseph D' Aleo has published articles which show a good correlation between temperature change and PDO's/AMO's (and almost almost no correlation with CO2). The magnitude can be seen in these correlations. The correlations I've seen are somewhat numerological. They provide no physical basis for causation, and do not allow for causation from other sources (such as CO2, the sun or aerosols). Unless they can do that, I'll reserve judgement. It's in the Q term. Agreed, the low end implies very little positive feedback. But it is also optimistic to depend on the low end.
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