Comments on: Clarifying the Role of the Sun and Global Temperatures http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/ a forum for the discussion of issues concerning the natural environment Sun, 21 Mar 2010 05:45:29 +1000 http://wordpress.org/?v=2.8 hourly 1 By: Ett par viktiga studier « Klimatmatt http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-129174 Ett par viktiga studier « Klimatmatt Sun, 16 Aug 2009 03:23:21 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-129174 [...] Marohasy påpekar att Baker understryker att solens magnetiska fält, via en omvänd relation till grad av jonisering [...] [...] Marohasy påpekar att Baker understryker att solens magnetiska fält, via en omvänd relation till grad av jonisering [...]

]]> By: R James http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-74285 R James Fri, 12 Dec 2008 02:33:19 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-74285 Why try to do linear regression to a non-linear system? I agree there's been no warming over the past 11 years - 2008 certainly will drag it down. There still may be a continuing upward trend. (nothing to do with CO2). I'm yet to find any data that substantiates the hypothesis that increasing CO2 concentration increases temperature (outside models that haven't worked). However, it's hard to ignore the solar/Maunder correlation. Based on solar activity, and long term historical data, I'd predict we're now coming into a minor cooling period, with a severe cooling trough anytime in the next 1,000 years, Why try to do linear regression to a non-linear system? I agree there’s been no warming over the past 11 years – 2008 certainly will drag it down. There still may be a continuing upward trend. (nothing to do with CO2).

I’m yet to find any data that substantiates the hypothesis that increasing CO2 concentration increases temperature (outside models that haven’t worked). However, it’s hard to ignore the solar/Maunder correlation. Based on solar activity, and long term historical data, I’d predict we’re now coming into a minor cooling period, with a severe cooling trough anytime in the next 1,000 years,

]]> By: Eli Rabett http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73999 Eli Rabett Wed, 10 Dec 2008 02:26:02 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73999 The higher the number of parameters you need for a fit, the fewer degrees of freedom you have (e.g. the number of data points gives a degree of freedom, if they are autocorrelated there fewer), a fit parameter takes away one degree of freedom. Given that you want to fit with as few parameters as possible consistent with the trend. The higher the number of parameters you need for a fit, the fewer degrees of freedom you have (e.g. the number of data points gives a degree of freedom, if they are autocorrelated there fewer), a fit parameter takes away one degree of freedom. Given that you want to fit with as few parameters as possible consistent with the trend.

]]> By: Bernard J. http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73934 Bernard J. Tue, 09 Dec 2008 13:28:29 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73934 "Wouldn’t a preference for a linear fit also involve assumptions. Specifically, it would fail to pick up any reversal in trends." John. There are a number of ways of testing one's fitting of a LoBF, ranging from a simple eyeballing of the spread of points that all first-years are taught to do, through to monitoring the trend in residuals and to more complex computations of the 'appropriateness' of the model's fit. In all instances Ockham's razor applies, and a fourth-order polynomial is hardly this. Most important to recall is that lines of fit are only applicable to the data used to derive them, and not to portions of the x-axis that lie outside the analysed section. If such inappropriate extrapolations WERE done, linear regressions (where they fit the data) are less fraught with the confoundment of what might be happening in the near neighbourhood outside of the fitted section, compared with high order polynomials that just fall over like drunken sailors. “Wouldn’t a preference for a linear fit also involve assumptions. Specifically, it would fail to pick up any reversal in trends.”

John.

There are a number of ways of testing one’s fitting of a LoBF, ranging from a simple eyeballing of the spread of points that all first-years are taught to do, through to monitoring the trend in residuals and to more complex computations of the ‘appropriateness’ of the model’s fit.

In all instances Ockham’s razor applies, and a fourth-order polynomial is hardly this.

Most important to recall is that lines of fit are only applicable to the data used to derive them, and not to portions of the x-axis that lie outside the analysed section. If such inappropriate extrapolations WERE done, linear regressions (where they fit the data) are less fraught with the confoundment of what might be happening in the near neighbourhood outside of the fitted section, compared with high order polynomials that just fall over like drunken sailors.

]]> By: SJT http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73896 SJT Tue, 09 Dec 2008 02:31:12 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73896 "I’m not saying the trend is reversing. I’m just saying that a linear fit isn’t always appropriate." Fair enough. Are you actually trying to have a rational conversation here on the pros and cons of the actual debate? That would be nice for a change. :) “I’m not saying the trend is reversing. I’m just saying that a linear fit isn’t always appropriate.”

Fair enough. Are you actually trying to have a rational conversation here on the pros and cons of the actual debate? That would be nice for a change. :)

]]> By: John Humphreys http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73873 John Humphreys Mon, 08 Dec 2008 23:10:08 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73873 Wouldn't a preference for a linear fit also involve assumptions. Specifically, it would fail to pick up any reversal in trends. I'm not saying the trend is reversing. I'm just saying that a linear fit isn't always appropriate. Wouldn’t a preference for a linear fit also involve assumptions. Specifically, it would fail to pick up any reversal in trends.

I’m not saying the trend is reversing. I’m just saying that a linear fit isn’t always appropriate.

]]> By: SJT http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73835 SJT Mon, 08 Dec 2008 09:43:34 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73835 <blockquote>SJT: as you are sure you are always right, what have you to fear? My reference was of course to Hansen proposing Nuremburg for the CEOs of Exxon etc. and you are clearly a Hansenite.</blockquote> Haven't got a clue, have you?

SJT: as you are sure you are always right, what have you to fear? My reference was of course to Hansen proposing Nuremburg for the CEOs of Exxon etc. and you are clearly a Hansenite.

Haven’t got a clue, have you?

]]> By: SJT http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73834 SJT Mon, 08 Dec 2008 09:23:10 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73834 In other words, you have nothing. Worked out the difference between an observation and a proxy yet? In other words, you have nothing. Worked out the difference between an observation and a proxy yet?

]]> By: Eyrie http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73830 Eyrie Mon, 08 Dec 2008 08:18:31 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73830 Still digging I see, SJT. Dear God but you are breathtakingly stupid. Do you have trouble remembering how to breathe? Still digging I see, SJT. Dear God but you are breathtakingly stupid. Do you have trouble remembering how to breathe?

]]> By: Tim Curtin http://jennifermarohasy.com/blog/2008/12/clarifying-the-role-of-the-sun-and-global-temperature-trends/comment-page-3/#comment-73826 Tim Curtin Mon, 08 Dec 2008 05:00:00 +0000 http://jennifermarohasy.com/blog/?p=3499#comment-73826 SJT: as you are sure you are always right, what have you to fear? My reference was of course to Hansen proposing Nuremburg for the CEOs of Exxon etc. and you are clearly a Hansenite. If the cap fits wear it. But here as ever you seize on any esxcuse to avoid answering my questions. Again, what is the optimal level of [CO2] for world food production? Is Hansen right, 350, when world food production was 50% less than it is now at 385? But if you can't stand the heat keep out! Best SJT: as you are sure you are always right, what have you to fear? My reference was of course to Hansen proposing Nuremburg for the CEOs of Exxon etc. and you are clearly a Hansenite. If the cap fits wear it. But here as ever you seize on any esxcuse to avoid answering my questions. Again, what is the optimal level of [CO2] for world food production? Is Hansen right, 350, when world food production was 50% less than it is now at 385? But if you can’t stand the heat keep out!

Best

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