Comments on: CO2 and Temperature: which predicts which? http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/ "All manner of statistical analyses cheerfully undertaken." Tue, 19 Aug 2008 22:23:37 +0000 http://wordpress.org/?v=2.3.3 By: Larry Huld http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-7337 Larry Huld Fri, 04 Jul 2008 05:58:50 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-7337 This is a quite late comment and I am not sure if William already has performed the following calculations. How do the monthly (?ies) graphs look like when you compare them with land measurements for the same time 1979-2007? I am curious. This is a quite late comment and I am not sure if William already has performed the following calculations.
How do the monthly (?ies) graphs look like when you compare them with land measurements for the same time 1979-2007?
I am curious.

]]> By: Peter Gallagher http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-7253 Peter Gallagher Sat, 14 Jun 2008 08:41:36 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-7253 I've just caught up with this post, William. A lovely piece of empirical enquiry. Straightforward, simple and graphic. I had been asking myself (incoherently) these questions about the direction of causality for months. Your dissection of the data clarifies things (despite the limits, which you acknowledge, of the analysis). Thank you . Peter I’ve just caught up with this post, William. A lovely piece of empirical enquiry. Straightforward, simple and graphic. I had been asking myself (incoherently) these questions about the direction of causality for months. Your dissection of the data clarifies things (despite the limits, which you acknowledge, of the analysis). Thank you .

Peter

]]> By: Ferdinand Engelbeen http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4231 Ferdinand Engelbeen Tue, 29 Apr 2008 07:35:41 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4231 It seems difficult to include working references to the net... The Vostok CO2/T covariance can be seen at: <a href="http://www.ferdinand-engelbeen.be/klimaat/correlation.html" rel="nofollow">http://www.ferdinand-engelbeen.be/klimaat/correlation.html</a> It seems difficult to include working references to the net… The Vostok CO2/T covariance can be seen at:

http://www.ferdinand-engelbeen.be/klimaat/correlation.html

]]> By: Ferdinand Engelbeen http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4230 Ferdinand Engelbeen Tue, 29 Apr 2008 07:31:43 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4230 The link in #66 doesn't work, here is the complete URL: http://www.ferdinand-engelbeen.be/klimaat/correlation.html The link in #66 doesn’t work, here is the complete URL:
http://www.ferdinand-engelbeen.be/klimaat/correlation.html

]]> By: Ferdinand Engelbeen http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4229 Ferdinand Engelbeen Tue, 29 Apr 2008 07:28:01 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4229 Bernie, The increase of CO2 as result of temperature changes indeed is far too small to induce a runaway reaction (the feedback factor is far less than 1). Further, the largest feedback mechanism with increasing temperatures is ice/snow albedo, which played an important role during ice age - interglacial transitions (and reverse), far less today, as we are already in an interglacial. Thus increasing CO2 levels may have a (limited) influence on temperature, but I don't see that it will introduce a runaway reaction... We should have a look at the high-CO2/T periods like the Cretaceous to see what the CO2/T ratio was (still without a Venus-like runaway atmopshere), although the data from that period have wide error margins... Bernie,

The increase of CO2 as result of temperature changes indeed is far too small to induce a runaway reaction (the feedback factor is far less than 1).

Further, the largest feedback mechanism with increasing temperatures is ice/snow albedo, which played an important role during ice age - interglacial transitions (and reverse), far less today, as we are already in an interglacial. Thus increasing CO2 levels may have a (limited) influence on temperature, but I don’t see that it will introduce a runaway reaction…

We should have a look at the high-CO2/T periods like the Cretaceous to see what the CO2/T ratio was (still without a Venus-like runaway atmopshere), although the data from that period have wide error margins…

]]> By: Mike D. http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4225 Mike D. Tue, 29 Apr 2008 06:26:48 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4225 The intellectual equivalents of strip clubs are strip clubs. But what about strange attractors? Mandelbrot sets? What is the fractal dimension of clouds? Random is just another word for nothing left to lose; chaos has charisma. And why Poisson? The intellectual equivalents of strip clubs are strip clubs.

But what about strange attractors? Mandelbrot sets? What is the fractal dimension of clouds? Random is just another word for nothing left to lose; chaos has charisma.

And why Poisson?

]]> By: Bernie http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4209 Bernie Tue, 29 Apr 2008 02:15:36 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4209 OK, but bottom line that sounds like you do not see a runaway GHG effect? So what does this mean with respect to dCO2 ==> dT as opposed to dT ==> dCO2. It appears that you are saying that the magnitude of the change in CO2 must be the primary driver, rather than any feedback mechanism inducing ever increasing amounts of CO2. If so, then no short term catastrophic warming> OK, but bottom line that sounds like you do not see a runaway GHG effect?
So what does this mean with respect to dCO2 ==> dT as opposed to dT ==> dCO2.
It appears that you are saying that the magnitude of the change in CO2 must be the primary driver, rather than any feedback mechanism inducing ever increasing amounts of CO2. If so, then no short term catastrophic warming>

]]> By: Ferdinand Engelbeen http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4182 Ferdinand Engelbeen Mon, 28 Apr 2008 23:18:25 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4182 Bernie, If we take the last about million years as base, there seems to be an upper limit for the influence of temperature on CO2 levels of about 8 ppmv/?C. That includes (very) long feedback times like changes in vegetation growth (including area limits), ice cover and (deep) ocean currents. That doesn't include very high temperatures and CO2 levels like we have had during the Cretaceous, but it includes the Eemian, about 120,000 years ago, when temperatures at high latitudes probably were 5?C higher (Alaska), and a (large) part of the Greenland ice sheet was melted. The interesting part is that despite the highly non-linear reaction of a lot of biological and physico-chemical processes on temperature changes, the sum of al these reactions looks quite linear in the Vostok (and the Epica) ice cores... See <a>here</a>. Bernie,

If we take the last about million years as base, there seems to be an upper limit for the influence of temperature on CO2 levels of about 8 ppmv/?C. That includes (very) long feedback times like changes in vegetation growth (including area limits), ice cover and (deep) ocean currents.

That doesn’t include very high temperatures and CO2 levels like we have had during the Cretaceous, but it includes the Eemian, about 120,000 years ago, when temperatures at high latitudes probably were 5?C higher (Alaska), and a (large) part of the Greenland ice sheet was melted.

The interesting part is that despite the highly non-linear reaction of a lot of biological and physico-chemical processes on temperature changes, the sum of al these reactions looks quite linear in the Vostok (and the Epica) ice cores… See here.

]]> By: Bernie http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4175 Bernie Mon, 28 Apr 2008 22:04:44 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4175 Ferdinand: I didn't understand this bit: "These play a smaller role on longer term, as most levels out. For the past 50 years of CO2 data, the temperature influence is less than 2 ppmv for a 60 ppmv increase. " Are you putting a bound on the positive feedback loop from increase temperature on additional increases on CO2 from stored sources? Ferdinand:
I didn’t understand this bit:
“These play a smaller role on longer term, as most levels out. For the past 50 years of CO2 data, the temperature influence is less than 2 ppmv for a 60 ppmv increase. ”
Are you putting a bound on the positive feedback loop from increase temperature on additional increases on CO2 from stored sources?

]]> By: Ferdinand Engelbeen http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4172 Ferdinand Engelbeen Mon, 28 Apr 2008 20:07:09 +0000 http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/#comment-4172 Some (late) comment here... What I am missing is that one need quite different lags for different time frames. For the long-term (Vostok based) influence of temperature on CO2 levels is about 8 ppmv/?C, with lags of 800 +/- 600 years during a ice age - interglacian transition and several thousands of years the other way out. The 8 ppmv/?C also holds for the past 1,000 years, until the start of the industrial revolution (Law Dome ice core data), with a lag of about 50 years. Current short time influence of temperature on CO2 levels is about 3 ppmv/?C, not on CO2 levels, but modulating the CO2 increase <strong>speed</strong>, with a lag of about a month, while the bulk of the increase is caused by the emissions. If you want a formula: Catm(new) = Catm(old) + 0.55*CO2(emissions) + 3*dT The concentration of CO2 in the atmosphere increases with about 55% of the accumulated emissions, modulated by temperature differences. These play a smaller role on longer term, as most levels out. For the past 50 years of CO2 data, the temperature influence is less than 2 ppmv for a 60 ppmv increase. The correlation between accumulated CO2 emissions and increase in the atmosphere is a near fit (R^2 over 0.99). The other way out, the influence of temperature on CO2 is more difficult to know, as there is a (probably) very small signal within a lot of noise. Thus it will take much more time to know the real impact of CO2 temperature. From the far past (Vostok), we know that the influence is small, as a drop of 40 ppmv at the end of the Eemian (the last interglacial) had no measurable influence on temperature, within the measurement accuracy... Some (late) comment here…

What I am missing is that one need quite different lags for different time frames.

For the long-term (Vostok based) influence of temperature on CO2 levels is about 8 ppmv/?C, with lags of 800 +/- 600 years during a ice age - interglacian transition and several thousands of years the other way out. The 8 ppmv/?C also holds for the past 1,000 years, until the start of the industrial revolution (Law Dome ice core data), with a lag of about 50 years.

Current short time influence of temperature on CO2 levels is about 3 ppmv/?C, not on CO2 levels, but modulating the CO2 increase speed, with a lag of about a month, while the bulk of the increase is caused by the emissions.

If you want a formula:
Catm(new) = Catm(old) + 0.55*CO2(emissions) + 3*dT

The concentration of CO2 in the atmosphere increases with about 55% of the accumulated emissions, modulated by temperature differences. These play a smaller role on longer term, as most levels out. For the past 50 years of CO2 data, the temperature influence is less than 2 ppmv for a 60 ppmv increase. The correlation between accumulated CO2 emissions and increase in the atmosphere is a near fit (R^2 over 0.99).

The other way out, the influence of temperature on CO2 is more difficult to know, as there is a (probably) very small signal within a lot of noise. Thus it will take much more time to know the real impact of CO2 temperature. From the far past (Vostok), we know that the influence is small, as a drop of 40 ppmv at the end of the Eemian (the last interglacial) had no measurable influence on temperature, within the measurement accuracy…

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