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Post by duwayne on Dec 13, 2015 18:15:04 GMT
From the link:
"Kyoji Kimoto shows why the basic global warming hypothesis may be wrong. He shows doubling carbon dioxide in the absence of feedbacks will warm the Earth by only 0.14 degrees C."(My bold) This never was the claim. The AGW hypothesis was that increasing CO2 increased temperatures slightly that led to water vapor increasing in the atmosphere that led to more warming that led to water vaoor increasing in the atmosphere.... etc.. And the climate then enters an iterative feedback cycle leading to the oceans boiling. The AGW hypothesis depends on positive feedback. So the paper is arguing against a straw man. (We know that the AGW hypothesis also glosses over the fact that Earth has had thousands of years with higher levels of CO2 and no runaway positive feedback occurred. So the hypothesis does not even have face validity. ) Nautonnier, I may be misreading this, but I don't think he is questioning the "feedback". I think he questions the Planck response(climate sensitivity with zero feedback) which then must be multiplied by the feedback ratio to get the total climate sensitivity. |
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Post by sigurdur on Dec 13, 2015 18:27:21 GMT
www.earth-syst-dynam-discuss.net/4/25/2013/esdd-4-25-2013.htmlTop-of-the-Atmosphere (TOA) net radiative flux anomalies from Clouds and Earth's Radiant Energy Systems (CERES) Energy Balanced and Filled (EBAF) and surface air temperature anomalies from HadCRUT3 were compared for the time interval September 2000–May 2011. In a phase plane plot with the radiative flux anomalies lagging the temperature anomalies with 7 months the phase plane curve approached straight lines during about an eight months long period at the beginning and a five year period at the end of the interval. Both of those periods, but more clearly the latter one, could be connected to the occurrence of distinct El Niño Southern Oscillation (ENSO) episodes. This result is explained by using a hypothesis stating that non-radiative forcing connected to the ENSO is dominating the temperature changes during those two periods and that there is a lag between the temperature change and the radiative flux feedback. According to the hypothesis the slopes of the straight lines equal the value of the climate feedback parameter. By linear regression based on the mentioned five year period the value of the climate feedback parameter was estimated to 5.5 ± 0.6 W m−2 K−1 (± two standard errors).
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Post by sigurdur on Dec 20, 2015 0:59:09 GMT
Many weather and climate models to call their radiation schemes only every 3 h, which we show can lead to a stratospheric temperature overestimate of 3–5 K and wavenumber-8 fluctuations in top-of-atmosphere (TOA) net shortwave flux around the tropics of amplitude 1.6 W m−2 onlinelibrary.wiley.com/doi/10.1002/2015GL066868/abstract |
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Post by duwayne on Nov 27, 2020 17:56:57 GMT
It's hard to believe the last post on "Climate Models" was 5 years ago. There is a new paper with an updated, lower estimate of climate sensitivity. I'd like to see Judy Curry or Anthony Watts put this up on their sites for discussion. link |
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Post by sigurdur on Nov 29, 2020 0:43:58 GMT
www.frontiersin.org/articles/10.3389/feart.2020.559337/fullM20 examine three global sets of temperature data for oscillatory signals, all spanning a minimum length of 158 years: Control simulations (control runs of the IPCC model ensemble CMIP5, using pre-industrial conditions of the atmosphere without any external forcing so that “any apparently oscillatory behavior must arise from internal variability”), historical observations (annualized global monthly average surface temperatures from the HadCRUT4 land and ocean surface temperature dataset), and historical simulations (IPCC model ensemble CMIP5, containing external anthropogenic and natural forcing). They find robust significant spectral peaks in the multidecadal AMO range (period 40–70 years) in the historical observations and the historical simulations, but not in the control simulations. However, the latter data set is the only one that covers a greater length of time, with almost half of the model runs spanning 500 years or more.
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Post by duwayne on Nov 29, 2020 15:13:45 GMT
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Post by sigurdur on Nov 30, 2020 18:01:28 GMT
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