Category Archives: Sensitivity & feedbacks

Emergent constraints on climate sensitivity: Part I

by Nic Lewis

Emergent constraints on climate sensitivity:  their nature and assessment of validity.

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Recent research on aerosol forcing of the CMIP5 models

by Frank Bosse

A few days ago a paper (Sato et al) dealing with some aspects of the “Aerosol Cloud Interactions”, (ACI, also called “aerosol indirect effects”) was released. It bolsters the conclusions of earlier papers: the effective radiative forcing from ACI (ERFaci) is smaller than thought, perhaps near zero .

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Nature Unbound VIII – Modern global warming

by Javier

Summary: Modern Global Warming has been taking place for the past 300 years. It is the last of several multi-century warming periods that have happened during the Neoglacial cooling of the past 3000 years. Analysis of Holocene climate cycles shows that the period 1600-2100 AD should be a period of warming. The evidence suggests that Modern Global Warming is within Holocene variability, but the cryosphere displays a non-cyclical retreat that appears to have undone thousands of years of Neoglacial ice advance. The last 70 out of 300 years of Modern Global Warming are characterized by human-caused, extremely unusual, rapidly increasing CO2 levels. In stark contrast with this rapidly accelerating anthropogenic forcing, global temperature and sea level appear to have continued their rising trend with no perceptible evidence of added acceleration. The evidence supports a higher sensitivity to CO2 in the cryosphere, suggesting a negative feedback by H2O, that prevents CO2 from having the same effect elsewhere.

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Marvel et al.’s new paper on estimating climate sensitivity from observations

by Nic Lewis

Recently a new model-based paper on climate sensitivity was published by Kate Marvel, Gavin Schmidt and others, titled ‘Internal variability and disequilibrium confound estimates of climate sensitivity from observations’.[1]

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Reply to Patrick Brown’s response to comments on his Nature article

by Nic Lewis

My reply to Patrick Brown’s response to my my comments on his Nature article.

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Greater future global warming (still) predicted from Earth’s recent energy budget

by Patrick Brown

A response to Nic Lewis’ post A closer look shows global warming will not be greater than we thought.

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Brown and Caldeira: A closer look shows global warming will not be greater than we thought

by Nic Lewis

A critique of a recent paper by Brown and Caldeira published in Nature that predicted greater than expected global warming.

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