Reconciling Model-Observation Reconciliations

Climate Audit

Two very different representations of consistency between models and observations are popularly circulated. On the one hand, John Christy and Roy Spencer have frequently shown a graphic which purports to show a marked discrepancy between models and observations in tropical mid-troposphere, while, on the other hand, Zeke Hausfather, among others, have shown graphics which purport to show no discrepancy whatever between models and observations.  I’ve commented on this topic on a number of occasions over the years, including two posts discussing AR5 graphics (here, here) with an update comparison in 2016 (here) and in 2017 (tweet).

There are several moving parts in such comparisons: troposphere or surface, tropical or global. Choice of reference period affects the rhetorical impression of time series plots.  Boxplot comparisons of trends avoids this problem. I’ve presented such boxplots in the past and update for today’s post.

I’ll also…

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Steve Koonin: A Deceptive New Report on Climate

Climate Etc.

by Judith Curry

Red-teaming the the U.S. government’s Climate Science Special Report on the topic of sea level rise.

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Stanford Prof sues scientists who debunked him – demands $10M

Climate Etc.

by Judith Curry

Mannian litigation gone wild. — Steve McIntyre

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Are Climate Models Overstating Warming?

Climate Etc.

by Ross McKitrick

A number of authors, including the IPCC, have argued that climate models have systematically overstated the rate of global warming in recent decades. A recent paper by Millar et al. (2017) presented the same finding in a diagram of temperature change versus cumulative carbon emissions since 1870.

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Warm periods in the 20th century are not unprecedented during the last 2,000 years

Watts Up With That?

Public Release: 8-Aug-2017

From Eurekalert

Institute of Atmospheric Physics, Chinese Academy of Sciences

147467_webIMAGE: 2,000-year temperature reconstruction in China. view more

Credit: Yang Liu & Jingyun Zheng

A great deal of evidence relating to ancient climate variation is preserved in proxy data such as tree rings, lake sediments, ice cores, stalagmites, corals and historical documents, and these sources carry great significance in evaluating the 20th century warming in the context of the last two millennia.

Prof. Quansheng Ge and his group from the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, collected a large number of proxies and reconstructed a 2000-year temperature series in China with a 10-year resolution, enabling them to quantitatively reveal the characteristics of temperature change in China over a common era.

“We found four warm epochs,” says Prof. Ge, “which were AD 1 to AD 200, AD 550 to AD 760, AD…

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Nature Unbound IV – The 2400 Bray cycle. Part C

Climate Etc.

by Javier

A possible mechanism for the effect of solar variability on climate, whereby solar variability acts over the stratospheric pressure system transmitting the changes top-down, and over ocean temperatures bottom-up.

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Update on the strength of aerosol forcing

Climate Etc.

by Frank Bosse

Increasing evidence of small aerosol forcing supports the importance of internal variability in explaining inter hemispheric differences in temperature variability.

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