Climate Etc.

A new paper by Andrew Dessler et al. claims, based on 100 simulations of the historical period (1850 to date) by the MPI‑ESM1.1 climate model, that estimates of climate sensitivity using the energy-budget method can vary widely due to internal climate system variability.
I calculated what effect the uncertainty implied by the internal variability affecting the MPI‑ESM1.1 simulations had on the distribution of the primary climate sensitivity estimate in the recent Lewis & Curry energy-budget paper.

The result was a marginal narrowing of the Lewis & Curry sensitivity estimate. This is because the allowance for internal variability by Lewis & Curry is larger than internal variability in MPI‑ESM1.1.
Since historical period energy-budget sensitivity estimates are much more imprecise for other reasons, internal variability contributes little to their total uncertainty; it is an unimportant factor.
Nothing in the new Dessler et al. paper indicates that the Lewis & Curry energy-budget climate sensitivity estimates are likely to be biased low.

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509 Comments

Posted in Uncategorized

Impact of recent forcing and ocean heat uptake data on estimates of climate sensitivity

Posted on April 24, 2018 by niclewis | 283 comments

by Nic Lewis

We have now updated the LC15 paper with a new paper that has been published in the Journal of Climate “The impact of recent forcing and ocean heat uptake data on estimates of climate sensitivity“. The paper also addresses critiques of LC15.

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283 Comments

Posted in Sensitivity & feedbacks, Uncategorized

Week in review – science edition

Posted on April 20, 2018 by curryja | 495 comments

by Judith Curry

A few things that caught my eye this past week.

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495 Comments

Posted in Week in review

Four questions on climate change

Posted on April 18, 2018 by curryja | 201 comments

by Garth Paltridge

An essay on the state of climate change science.

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201 Comments

Posted in Sociology of science

Sea level rise acceleration (or not): Part VII U.S. coastal impacts

Posted on April 15, 2018 by curryja | 96 comments

by Judith Curry

The final installment in the CE series on sea level rise.

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96 Comments

Posted in Climate change impacts, Oceans

ENSO forecast for 2018

Posted on April 5, 2018 by curryja | 115 comments

by Jim Johnstone and Judith Curry

Attempting to breach the ENSO springtime ‘predictability barrier.’

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115 Comments

Posted in Prediction

Sea level rise acceleration (or not): Part VI. Projections for the 21st century

Posted on April 2, 2018 by curryja | 333 comments

by Judith Curry

The concern about sea level rise is driven primarily by projections of future sea level rise.

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333 Comments

Posted in Oceans

Emergent constraints on climate sensitivity in global models. Part III

Posted on March 29, 2018 by curryja | 78 comments

by Nic Lewis

The two strongest potentially credible constraints, and conclusions.

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78 Comments

Posted in Sensitivity & feedbacks

Emergent constraints on climate sensitivity: Part II

Posted on March 23, 2018 by curryja | 32 comments

by Nic Lewis

The four constraints that Caldwell assessed as credible.

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32 Comments

Posted in Sensitivity & feedbacks

Sea level rise acceleration (or not). Part V: detection & attribution

Posted on March 21, 2018 by curryja | 134 comments

by Judith Curry

In looking for causes, I have applied the ‘Sherlock Holmes procedure’ of eliminating one suspect after another. The procedure has left us without any good suspect. Thermal expansion was the candidate of choice at the time of the first IPCC review. The computed steric rise is too little, too late, and too linear. – Walter Munk

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134 Comments

Posted in Attribution, Oceans

Emergent constraints on climate sensitivity: Part I

Posted on March 19, 2018 by curryja | 119 comments

by Nic Lewis

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

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119 Comments

Posted in Sensitivity & feedbacks

Recent research on aerosol forcing of the CMIP5 models

Posted on March 11, 2018 by curryja | 169 comments

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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169 Comments

Posted in Sensitivity & feedbacks

What are the main sources of heat that account for the incremental rise in temperature on Earth?

Posted on March 9, 2018 by curryja | 227 comments

by Judith Curry

Suggestions for the climate ‘red team’ response.

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227 Comments

Posted in Attribution

Will advances in groundwater science force a paradigm shift in sea level rise attribution?

Posted on March 4, 2018 by curryja | 117 comments

by Jim Steele

A better accounting of natural groundwater discharge is needed to constrain the range of contributions to sea level rise. The greater the contribution from groundwater discharge, the smaller the adjustments used to amplify contributions from meltwater and thermal expansion.

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117 Comments

Posted in Attribution, Oceans

The Rise and Fall of Central England Temperatures: Part II

Posted on March 3, 2018 by curryja | 140 comments

by Tony Brown

This article examines the continued cooling of CET this century

Looks at a similar scenario of regional cooling in America
Examines CET related urbanisation issues, and the current Met office allowances for this
Notes the centuries long general warming of our climate.
Notes considerable English seasonal variability over the centuries
Examines the key component parts of the weather that affect the British Isles
Queries whether wind direction, strength and longevity are major factors in shaping our climate over the centuries.

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140 Comments

Posted in Attribution, Data and observations, History

Nature Unbound VIII – Modern global warming

Posted on February 26, 2018 by curryja | 871 comments

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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871 Comments

Posted in Attribution, Sensitivity & feedbacks

Sea level rise acceleration (or not): Part IV – Satellite era record

Posted on February 17, 2018 by curryja | 207 comments

by Judith Curry

Part IV of the Climate Etc. series on sea level rise focuses on the satellite era (since 1993), including the recent causes of sea level variations and arguments regarding the acceleration (or not) of recent sea level rise.

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207 Comments

Posted in Data and observations, Oceans

Update: libel cases and the ‘climate wars’

Posted on February 14, 2018 by curryja | 139 comments

by Judith Curry

Big news in the world of ‘climate wars’ – the libel case of Andrew Weaver versus Tim Ball has been dismissed by the judge — for a rather surprising reason.

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139 Comments

Posted in Sociology of science

Sea level rise acceleration (or not): Part III – 19th & 20th century observations

Posted on February 10, 2018 by curryja | 95 comments

By Judith Curry

“We are in the uncomfortable position of extrapolating into the next century without understanding the last.” – Walter Munk

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95 Comments

Posted in Data and observations, Oceans

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

Posted on February 5, 2018 by curryja | 784 comments

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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784 Comments

Posted in Sensitivity & feedbacks