Does this study from Dana Royer et al. rule out high and low values of climate sensitivity?

Question

"Here we estimate long-term equilibrium climate sensitivity by modelling carbon dioxide concentrations over the past 420 million years and comparing our calculations with a proxy record...We conclude that a climate sensitivity greater than 1.5°C has probably been a robust feature of the Earth’s climate system over the past 420 million years, regardless of temporal scaling."

"For [climate sensitivity] < 1.5°C, unreasonably high levels of atmospheric CO2 are required to maintain the necessary feedback effect. In the opposite extreme, if [climate sensitivity] is too large (>6°C), the silicate weathering feedback prevents atmospheric CO2 levels from reaching the high past values indicated by proxy data"
http://www.essc.psu.edu/essc_web/seminars/spring2007/RoyeretalNature07.pdf

'Skeptics' like Spencer and Lindzen have argued that climate sensitivity is closer to 0.5–1°C for a doubling of CO2. Do you think the work of Dana Royer et al. convincingly rules out these lower values of climate sensitivity ?

Answer 1

Another good paper. Put it in the scales with all the others, and it increases the already large weight.



Now up to the amplified feedback denialists to produce evidence for their low values.

Answer 2

Does it have some wieght? Sure.

Does is "convincingly rule out" lower values? No.

To be "convincing in the scientific realm you have to have a testable hypothesis and perfrom the necessary testing that verifies a claim. In addition the work must be published with enough detail such that anyone can duplicate the results of the original test. If said test can not be duplcated by others, even and yes especially skeptics, then it is of no scientific value.



This of course is the scientific method.

Answer 3

Not at all!!!



He has simply shown the correlation between the temps of the past and the CO2 Conc. The answer will still always overestimate due to the portion of the correlation occurring because CO2 increases as temps warm.



Paul B,

That weight is just paper weight until it actually addresses the true questions. Skeptics do not deny the correlation btw CO2 and temps. That is all this guy is showing.



I suggest you start to understand that the greenhouse effect and radiative forces only allows for the amount that CO2 can heat the earth by itself. So want to argue that the earth is going to warm by only 1 degree with a doubling of CO2, then you can ignore everything I have said, but given that you make absurd claims of 7 degrees of warming I suggest you look up what burden of proof means.

Answer 4

<<.To be "convincing in the scientific realm you have to have a testable hypothesis and perfrom the necessary testing that verifies a claim. In addition the work must be published with enough detail such that anyone can duplicate the results of the original test. If said test can not be duplcated by others, even and yes especially skeptics, then it is of no scientific value.>>



I take it then that you do not belive Man evolved from ape-like creatures, or that the Universe was hot and rapidly expanding in early times.

your



I also note that << In addition the work must be published with enough detail such that anyone can duplicate the results of the original test>> assumes all science is experiments, and that the Theory of Relativity (Special and General) as well as the Dirac Equation should not have been published. It isuite proper for theories to make predictions that cannot be immediately verified.



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I've heard this "scientific method" thing on this board a lot and from a high school teacher. I have never heard an actual scientist refer to it...except me referring to it negatively.